/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.io;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayInputStream;
import java.io.CharArrayWriter;
import java.io.Closeable;
import java.io.EOFException;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.URI;
import java.net.URL;
import java.net.URLConnection;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.Selector;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.apache.commons.io.output.ByteArrayOutputStream;
import org.apache.commons.io.output.StringBuilderWriter;

General IO stream manipulation utilities.

This class provides static utility methods for input/output operations.

[Deprecated] closeQuietly - these methods close a stream ignoring nulls and exceptions
toXxx/read - these methods read data from a stream
write - these methods write data to a stream
copy - these methods copy all the data from one stream to another
contentEquals - these methods compare the content of two streams


The byte-to-char methods and char-to-byte methods involve a conversion step.
Two methods are provided in each case, one that uses the platform default
encoding and the other which allows you to specify an encoding. You are
encouraged to always specify an encoding because relying on the platform
default can lead to unexpected results, for example when moving from
development to production.

All the methods in this class that read a stream are buffered internally.
This means that there is no cause to use a BufferedInputStream
or BufferedReader. The default buffer size of 4K has been shown
to be efficient in tests.

The various copy methods all delegate the actual copying to one of the following methods:

copyLarge(InputStream, OutputStream, byte[])
copyLarge(InputStream, OutputStream, long, long, byte[])
copyLarge(Reader, Writer, char[])
copyLarge(Reader, Writer, long, long, char[])
 For example, copy(InputStream, OutputStream) calls copyLarge(InputStream, OutputStream) which calls copy(InputStream, OutputStream, int) which creates the buffer and calls copyLarge(InputStream, OutputStream, byte[]). 

Applications can re-use buffers by using the underlying methods directly.
This may improve performance for applications that need to do a lot of copying.

Wherever possible, the methods in this class do not flush or close
the stream. This is to avoid making non-portable assumptions about the
streams' origin and further use. Thus the caller is still responsible for
closing streams after use.

Origin of code: Excalibur.
/**
 * General IO stream manipulation utilities.
 * <p>
 * This class provides static utility methods for input/output operations.
 * <ul>
 * <li><b>[Deprecated]</b> closeQuietly - these methods close a stream ignoring nulls and exceptions
 * <li>toXxx/read - these methods read data from a stream
 * <li>write - these methods write data to a stream
 * <li>copy - these methods copy all the data from one stream to another
 * <li>contentEquals - these methods compare the content of two streams
 * </ul>
 * <p>
 * The byte-to-char methods and char-to-byte methods involve a conversion step.
 * Two methods are provided in each case, one that uses the platform default
 * encoding and the other which allows you to specify an encoding. You are
 * encouraged to always specify an encoding because relying on the platform
 * default can lead to unexpected results, for example when moving from
 * development to production.
 * <p>
 * All the methods in this class that read a stream are buffered internally.
 * This means that there is no cause to use a <code>BufferedInputStream</code>
 * or <code>BufferedReader</code>. The default buffer size of 4K has been shown
 * to be efficient in tests.
 * <p>
 * The various copy methods all delegate the actual copying to one of the following methods:
 * <ul>
 * <li>{@link #copyLarge(InputStream, OutputStream, byte[])}</li>
 * <li>{@link #copyLarge(InputStream, OutputStream, long, long, byte[])}</li>
 * <li>{@link #copyLarge(Reader, Writer, char[])}</li>
 * <li>{@link #copyLarge(Reader, Writer, long, long, char[])}</li>
 * </ul>
 * For example, {@link #copy(InputStream, OutputStream)} calls {@link #copyLarge(InputStream, OutputStream)}
 * which calls {@link #copy(InputStream, OutputStream, int)} which creates the buffer and calls
 * {@link #copyLarge(InputStream, OutputStream, byte[])}.
 * <p>
 * Applications can re-use buffers by using the underlying methods directly.
 * This may improve performance for applications that need to do a lot of copying.
 * <p>
 * Wherever possible, the methods in this class do <em>not</em> flush or close
 * the stream. This is to avoid making non-portable assumptions about the
 * streams' origin and further use. Thus the caller is still responsible for
 * closing streams after use.
 * <p>
 * Origin of code: Excalibur.
 *
 */
public class IOUtils {
    // NOTE: This class is focused on InputStream, OutputStream, Reader and
    // Writer. Each method should take at least one of these as a parameter,
    // or return one of them.

    
Represents the end-of-file (or stream).
Since:
2.5 (made public)/**
     * Represents the end-of-file (or stream).
     * @since 2.5 (made public)
     */
    public static final int EOF = -1;

    
The Unix directory separator character.
/**
     * The Unix directory separator character.
     */
    public static final char DIR_SEPARATOR_UNIX = '/';
    
The Windows directory separator character.
/**
     * The Windows directory separator character.
     */
    public static final char DIR_SEPARATOR_WINDOWS = '\\';
    
The system directory separator character.
/**
     * The system directory separator character.
     */
    public static final char DIR_SEPARATOR = File.separatorChar;
    
The Unix line separator string.
/**
     * The Unix line separator string.
     */
    public static final String LINE_SEPARATOR_UNIX = "\n";
    
The Windows line separator string.
/**
     * The Windows line separator string.
     */
    public static final String LINE_SEPARATOR_WINDOWS = "\r\n";
    
The system line separator string.
/**
     * The system line separator string.
     */
    public static final String LINE_SEPARATOR;

    static {
        // avoid security issues
        try (final StringBuilderWriter buf = new StringBuilderWriter(4);
                final PrintWriter out = new PrintWriter(buf)) {
            out.println();
            LINE_SEPARATOR = buf.toString();
        }
    }

    
The default buffer size (4096) to use for copyLarge(InputStream, OutputStream) and copyLarge(Reader, Writer) /**
     * The default buffer size ({@value}) to use for
     * {@link #copyLarge(InputStream, OutputStream)}
     * and
     * {@link #copyLarge(Reader, Writer)}
     */
    private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;

    
The default buffer size to use for the skip() methods.
/**
     * The default buffer size to use for the skip() methods.
     */
    private static final int SKIP_BUFFER_SIZE = 2048;

    // Allocated in the relevant skip method if necessary.
    /*
     * These buffers are static and are shared between threads.
     * This is possible because the buffers are write-only - the contents are never read.
     *
     * N.B. there is no need to synchronize when creating these because:
     * - we don't care if the buffer is created multiple times (the data is ignored)
     * - we always use the same size buffer, so if it it is recreated it will still be OK
     * (if the buffer size were variable, we would need to synch. to ensure some other thread
     * did not create a smaller one)
     */
    private static char[] SKIP_CHAR_BUFFER;
    private static byte[] SKIP_BYTE_BUFFER;

    
Instances should NOT be constructed in standard programming.
/**
     * Instances should NOT be constructed in standard programming.
     */
    public IOUtils() {
        super();
    }

    //-----------------------------------------------------------------------

    
Closes a URLConnection.
Params:
conn – the connection to close.
Since:
2.4/**
     * Closes a URLConnection.
     *
     * @param conn the connection to close.
     * @since 2.4
     */
    public static void close(final URLConnection conn) {
        if (conn instanceof HttpURLConnection) {
            ((HttpURLConnection) conn).disconnect();
        }
    }

    
Closes an Reader unconditionally.
 Equivalent to Reader.close(), except any exceptions will be ignored. This is typically used in finally blocks. 

Example code:
  char[] data = new char[1024];
  Reader in = null;
  try {
      in = new FileReader("foo.txt");
      in.read(data);
      in.close(); //close errors are handled
  } catch (Exception e) {
      // error handling
  } finally {
      IOUtils.closeQuietly(in);
  }

Params:
input – the Reader to close, may be null or already closed
See Also:
Throwable.addSuppressed(Throwable)
Deprecated:
As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
suppressed exceptions manually./**
     * Closes an <code>Reader</code> unconditionally.
     * <p>
     * Equivalent to {@link Reader#close()}, except any exceptions will be ignored.
     * This is typically used in finally blocks.
     * <p>
     * Example code:
     * <pre>
     *   char[] data = new char[1024];
     *   Reader in = null;
     *   try {
     *       in = new FileReader("foo.txt");
     *       in.read(data);
     *       in.close(); //close errors are handled
     *   } catch (Exception e) {
     *       // error handling
     *   } finally {
     *       IOUtils.closeQuietly(in);
     *   }
     * </pre>
     *
     * @param input the Reader to close, may be null or already closed
     *
     * @deprecated As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
     * suppressed exceptions manually.
     * @see Throwable#addSuppressed(java.lang.Throwable)
     */
    @Deprecated
    public static void closeQuietly(final Reader input) {
        closeQuietly((Closeable) input);
    }

    
Closes an Writer unconditionally.
 Equivalent to Writer.close(), except any exceptions will be ignored. This is typically used in finally blocks. 

Example code:
  Writer out = null;
  try {
      out = new StringWriter();
      out.write("Hello World");
      out.close(); //close errors are handled
  } catch (Exception e) {
      // error handling
  } finally {
      IOUtils.closeQuietly(out);
  }

Params:
output – the Writer to close, may be null or already closed
See Also:
Throwable.addSuppressed(Throwable)
Deprecated:
As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
suppressed exceptions manually./**
     * Closes an <code>Writer</code> unconditionally.
     * <p>
     * Equivalent to {@link Writer#close()}, except any exceptions will be ignored.
     * This is typically used in finally blocks.
     * <p>
     * Example code:
     * <pre>
     *   Writer out = null;
     *   try {
     *       out = new StringWriter();
     *       out.write("Hello World");
     *       out.close(); //close errors are handled
     *   } catch (Exception e) {
     *       // error handling
     *   } finally {
     *       IOUtils.closeQuietly(out);
     *   }
     * </pre>
     *
     * @param output the Writer to close, may be null or already closed
     *
     * @deprecated As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
     * suppressed exceptions manually.
     * @see Throwable#addSuppressed(java.lang.Throwable)
     */
    @Deprecated
    public static void closeQuietly(final Writer output) {
        closeQuietly((Closeable) output);
    }

    
Closes an InputStream unconditionally.
 Equivalent to InputStream.close(), except any exceptions will be ignored. This is typically used in finally blocks. 

Example code:
  byte[] data = new byte[1024];
  InputStream in = null;
  try {
      in = new FileInputStream("foo.txt");
      in.read(data);
      in.close(); //close errors are handled
  } catch (Exception e) {
      // error handling
  } finally {
      IOUtils.closeQuietly(in);
  }

Params:
input – the InputStream to close, may be null or already closed
See Also:
Throwable.addSuppressed(Throwable)
Deprecated:
As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
suppressed exceptions manually./**
     * Closes an <code>InputStream</code> unconditionally.
     * <p>
     * Equivalent to {@link InputStream#close()}, except any exceptions will be ignored.
     * This is typically used in finally blocks.
     * <p>
     * Example code:
     * <pre>
     *   byte[] data = new byte[1024];
     *   InputStream in = null;
     *   try {
     *       in = new FileInputStream("foo.txt");
     *       in.read(data);
     *       in.close(); //close errors are handled
     *   } catch (Exception e) {
     *       // error handling
     *   } finally {
     *       IOUtils.closeQuietly(in);
     *   }
     * </pre>
     *
     * @param input the InputStream to close, may be null or already closed
     *
     * @deprecated As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
     * suppressed exceptions manually.
     * @see Throwable#addSuppressed(java.lang.Throwable)
     */
    @Deprecated
    public static void closeQuietly(final InputStream input) {
        closeQuietly((Closeable) input);
    }

    
Closes an OutputStream unconditionally.
 Equivalent to OutputStream.close(), except any exceptions will be ignored. This is typically used in finally blocks. 

Example code:
byte[] data = "Hello, World".getBytes();
OutputStream out = null;
try {
    out = new FileOutputStream("foo.txt");
    out.write(data);
    out.close(); //close errors are handled
} catch (IOException e) {
    // error handling
} finally {
    IOUtils.closeQuietly(out);
}

Params:
output – the OutputStream to close, may be null or already closed
See Also:
Throwable.addSuppressed(Throwable)
Deprecated:
As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
suppressed exceptions manually./**
     * Closes an <code>OutputStream</code> unconditionally.
     * <p>
     * Equivalent to {@link OutputStream#close()}, except any exceptions will be ignored.
     * This is typically used in finally blocks.
     * <p>
     * Example code:
     * <pre>
     * byte[] data = "Hello, World".getBytes();
     *
     * OutputStream out = null;
     * try {
     *     out = new FileOutputStream("foo.txt");
     *     out.write(data);
     *     out.close(); //close errors are handled
     * } catch (IOException e) {
     *     // error handling
     * } finally {
     *     IOUtils.closeQuietly(out);
     * }
     * </pre>
     *
     * @param output the OutputStream to close, may be null or already closed
     *
     * @deprecated As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
     * suppressed exceptions manually.
     * @see Throwable#addSuppressed(java.lang.Throwable)
     */
    @Deprecated
    public static void closeQuietly(final OutputStream output) {
        closeQuietly((Closeable) output);
    }

    
Closes a Closeable unconditionally.
 Equivalent to Closeable.close(), except any exceptions will be ignored. This is typically used in finally blocks. 

Example code:

Closeable closeable = null;
try {
    closeable = new FileReader("foo.txt");
    // process closeable
    closeable.close();
} catch (Exception e) {
    // error handling
} finally {
    IOUtils.closeQuietly(closeable);
}


Closing all streams:

try {
    return IOUtils.copy(inputStream, outputStream);
} finally {
    IOUtils.closeQuietly(inputStream);
    IOUtils.closeQuietly(outputStream);
}

Params:
closeable – the objects to close, may be null or already closed
See Also:
Throwable.addSuppressed(Throwable)
Since:
2.0
Deprecated:
As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
suppressed exceptions manually./**
     * Closes a <code>Closeable</code> unconditionally.
     * <p>
     * Equivalent to {@link Closeable#close()}, except any exceptions will be ignored. This is typically used in
     * finally blocks.
     * <p>
     * Example code:
     * </p>
     * <pre>
     * Closeable closeable = null;
     * try {
     *     closeable = new FileReader(&quot;foo.txt&quot;);
     *     // process closeable
     *     closeable.close();
     * } catch (Exception e) {
     *     // error handling
     * } finally {
     *     IOUtils.closeQuietly(closeable);
     * }
     * </pre>
     * <p>
     * Closing all streams:
     * </p>
     * <pre>
     * try {
     *     return IOUtils.copy(inputStream, outputStream);
     * } finally {
     *     IOUtils.closeQuietly(inputStream);
     *     IOUtils.closeQuietly(outputStream);
     * }
     * </pre>
     *
     * @param closeable the objects to close, may be null or already closed
     * @since 2.0
     *
     * @deprecated As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
     * suppressed exceptions manually.
     * @see Throwable#addSuppressed(java.lang.Throwable)
     */
    @Deprecated
    public static void closeQuietly(final Closeable closeable) {
        try {
            if (closeable != null) {
                closeable.close();
            }
        } catch (final IOException ioe) {
            // ignore
        }
    }

    
Closes a Closeable unconditionally.
 Equivalent to Closeable.close(), except any exceptions will be ignored. 

This is typically used in finally blocks to ensure that the closeable is closed
even if an Exception was thrown before the normal close statement was reached.


It should not be used to replace the close statement(s)
which should be present for the non-exceptional case.


It is only intended to simplify tidying up where normal processing has already failed
and reporting close failure as well is not necessary or useful.

Example code:

Closeable closeable = null;
try {
    closeable = new FileReader("foo.txt");
    // processing using the closeable; may throw an Exception
    closeable.close(); // Normal close - exceptions not ignored
} catch (Exception e) {
    // error handling
} finally {
    IOUtils.closeQuietly(closeable); // In case normal close was skipped due to Exception
}


Closing all streams:


try {
    return IOUtils.copy(inputStream, outputStream);
} finally {
    IOUtils.closeQuietly(inputStream, outputStream);
}

Params:
closeables – the objects to close, may be null or already closed
See Also:
closeQuietly(Closeable)
Throwable.addSuppressed(Throwable)
Since:
2.5
Deprecated:
As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
suppressed exceptions manually./**
     * Closes a <code>Closeable</code> unconditionally.
     * <p>
     * Equivalent to {@link Closeable#close()}, except any exceptions will be ignored.
     * <p>
     * This is typically used in finally blocks to ensure that the closeable is closed
     * even if an Exception was thrown before the normal close statement was reached.
     * <br>
     * <b>It should not be used to replace the close statement(s)
     * which should be present for the non-exceptional case.</b>
     * <br>
     * It is only intended to simplify tidying up where normal processing has already failed
     * and reporting close failure as well is not necessary or useful.
     * <p>
     * Example code:
     * </p>
     * <pre>
     * Closeable closeable = null;
     * try {
     *     closeable = new FileReader(&quot;foo.txt&quot;);
     *     // processing using the closeable; may throw an Exception
     *     closeable.close(); // Normal close - exceptions not ignored
     * } catch (Exception e) {
     *     // error handling
     * } finally {
     *     <b>IOUtils.closeQuietly(closeable); // In case normal close was skipped due to Exception</b>
     * }
     * </pre>
     * <p>
     * Closing all streams:
     * <br>
     * <pre>
     * try {
     *     return IOUtils.copy(inputStream, outputStream);
     * } finally {
     *     IOUtils.closeQuietly(inputStream, outputStream);
     * }
     * </pre>
     *
     * @param closeables the objects to close, may be null or already closed
     * @see #closeQuietly(Closeable)
     * @since 2.5
     *
     * @deprecated As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
     * suppressed exceptions manually.
     * @see Throwable#addSuppressed(java.lang.Throwable)
     */
    @Deprecated
    public static void closeQuietly(final Closeable... closeables) {
        if (closeables == null) {
            return;
        }
        for (final Closeable closeable : closeables) {
            closeQuietly(closeable);
        }
    }

    
Closes a Socket unconditionally.
 Equivalent to Socket.close(), except any exceptions will be ignored. This is typically used in finally blocks. 

Example code:
  Socket socket = null;
  try {
      socket = new Socket("http://www.foo.com/", 80);
      // process socket
      socket.close();
  } catch (Exception e) {
      // error handling
  } finally {
      IOUtils.closeQuietly(socket);
  }

Params:
sock – the Socket to close, may be null or already closed
See Also:
Throwable.addSuppressed(Throwable)
Since:
2.0
Deprecated:
As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
suppressed exceptions manually./**
     * Closes a <code>Socket</code> unconditionally.
     * <p>
     * Equivalent to {@link Socket#close()}, except any exceptions will be ignored.
     * This is typically used in finally blocks.
     * <p>
     * Example code:
     * <pre>
     *   Socket socket = null;
     *   try {
     *       socket = new Socket("http://www.foo.com/", 80);
     *       // process socket
     *       socket.close();
     *   } catch (Exception e) {
     *       // error handling
     *   } finally {
     *       IOUtils.closeQuietly(socket);
     *   }
     * </pre>
     *
     * @param sock the Socket to close, may be null or already closed
     * @since 2.0
     *
     * @deprecated As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
     * suppressed exceptions manually.
     * @see Throwable#addSuppressed(java.lang.Throwable)
     */
    @Deprecated
    public static void closeQuietly(final Socket sock) {
        if (sock != null) {
            try {
                sock.close();
            } catch (final IOException ioe) {
                // ignored
            }
        }
    }

    
Closes a Selector unconditionally.
 Equivalent to Selector.close(), except any exceptions will be ignored. This is typically used in finally blocks. 

Example code:
  Selector selector = null;
  try {
      selector = Selector.open();
      // process socket
  } catch (Exception e) {
      // error handling
  } finally {
      IOUtils.closeQuietly(selector);
  }

Params:
selector – the Selector to close, may be null or already closed
See Also:
Throwable.addSuppressed(Throwable)
Since:
2.2
Deprecated:
As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
suppressed exceptions manually./**
     * Closes a <code>Selector</code> unconditionally.
     * <p>
     * Equivalent to {@link Selector#close()}, except any exceptions will be ignored.
     * This is typically used in finally blocks.
     * <p>
     * Example code:
     * <pre>
     *   Selector selector = null;
     *   try {
     *       selector = Selector.open();
     *       // process socket
     *
     *   } catch (Exception e) {
     *       // error handling
     *   } finally {
     *       IOUtils.closeQuietly(selector);
     *   }
     * </pre>
     *
     * @param selector the Selector to close, may be null or already closed
     * @since 2.2
     *
     * @deprecated As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
     * suppressed exceptions manually.
     * @see Throwable#addSuppressed(java.lang.Throwable)
     */
    @Deprecated
    public static void closeQuietly(final Selector selector) {
        if (selector != null) {
            try {
                selector.close();
            } catch (final IOException ioe) {
                // ignored
            }
        }
    }

    
Closes a ServerSocket unconditionally.
 Equivalent to ServerSocket.close(), except any exceptions will be ignored. This is typically used in finally blocks. 

Example code:
  ServerSocket socket = null;
  try {
      socket = new ServerSocket();
      // process socket
      socket.close();
  } catch (Exception e) {
      // error handling
  } finally {
      IOUtils.closeQuietly(socket);
  }

Params:
sock – the ServerSocket to close, may be null or already closed
See Also:
Throwable.addSuppressed(Throwable)
Since:
2.2
Deprecated:
As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
suppressed exceptions manually./**
     * Closes a <code>ServerSocket</code> unconditionally.
     * <p>
     * Equivalent to {@link ServerSocket#close()}, except any exceptions will be ignored.
     * This is typically used in finally blocks.
     * <p>
     * Example code:
     * <pre>
     *   ServerSocket socket = null;
     *   try {
     *       socket = new ServerSocket();
     *       // process socket
     *       socket.close();
     *   } catch (Exception e) {
     *       // error handling
     *   } finally {
     *       IOUtils.closeQuietly(socket);
     *   }
     * </pre>
     *
     * @param sock the ServerSocket to close, may be null or already closed
     * @since 2.2
     *
     * @deprecated As of 2.6 removed without replacement. Please use the try-with-resources statement or handle
     * suppressed exceptions manually.
     * @see Throwable#addSuppressed(java.lang.Throwable)
     */
    @Deprecated
    public static void closeQuietly(final ServerSocket sock) {
        if (sock != null) {
            try {
                sock.close();
            } catch (final IOException ioe) {
                // ignored
            }
        }
    }

    
Fetches entire contents of an InputStream and represent
same data as result InputStream.

This method is useful where,

Source InputStream is slow.
It has network resources associated, so we cannot keep it open for
long time.
It has network timeout associated.
 It can be used in favor of toByteArray(InputStream), since it avoids unnecessary allocation and copy of byte[].

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
Params:
input – Stream to be fully buffered.
Throws:
IOException – if an I/O error occurs
Returns:
A fully buffered stream.
Since:
2.0/**
     * Fetches entire contents of an <code>InputStream</code> and represent
     * same data as result InputStream.
     * <p>
     * This method is useful where,
     * <ul>
     * <li>Source InputStream is slow.</li>
     * <li>It has network resources associated, so we cannot keep it open for
     * long time.</li>
     * <li>It has network timeout associated.</li>
     * </ul>
     * It can be used in favor of {@link #toByteArray(InputStream)}, since it
     * avoids unnecessary allocation and copy of byte[].<br>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param input Stream to be fully buffered.
     * @return A fully buffered stream.
     * @throws IOException if an I/O error occurs
     * @since 2.0
     */
    public static InputStream toBufferedInputStream(final InputStream input) throws IOException {
        return ByteArrayOutputStream.toBufferedInputStream(input);
    }

    
Fetches entire contents of an InputStream and represent
same data as result InputStream.

This method is useful where,

Source InputStream is slow.
It has network resources associated, so we cannot keep it open for
long time.
It has network timeout associated.
 It can be used in favor of toByteArray(InputStream), since it avoids unnecessary allocation and copy of byte[].

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
Params:
input – Stream to be fully buffered.
size – the initial buffer size
Throws:
IOException – if an I/O error occurs
Returns:
A fully buffered stream.
Since:
2.5/**
     * Fetches entire contents of an <code>InputStream</code> and represent
     * same data as result InputStream.
     * <p>
     * This method is useful where,
     * <ul>
     * <li>Source InputStream is slow.</li>
     * <li>It has network resources associated, so we cannot keep it open for
     * long time.</li>
     * <li>It has network timeout associated.</li>
     * </ul>
     * It can be used in favor of {@link #toByteArray(InputStream)}, since it
     * avoids unnecessary allocation and copy of byte[].<br>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param input Stream to be fully buffered.
     * @param size the initial buffer size
     * @return A fully buffered stream.
     * @throws IOException if an I/O error occurs
     * @since 2.5
     */
    public static InputStream toBufferedInputStream(final InputStream input, final int size) throws IOException {
        return ByteArrayOutputStream.toBufferedInputStream(input, size);
    }

    
Returns the given reader if it is a BufferedReader, otherwise creates a BufferedReader from the given reader. 
Params:
reader – the reader to wrap or return (not null)
Throws:
NullPointerException – if the input parameter is null
See Also:
buffer(Reader)
Returns:
the given reader or a new BufferedReader for the given reader
Since:
2.2/**
     * Returns the given reader if it is a {@link BufferedReader}, otherwise creates a BufferedReader from the given
     * reader.
     *
     * @param reader the reader to wrap or return (not null)
     * @return the given reader or a new {@link BufferedReader} for the given reader
     * @throws NullPointerException if the input parameter is null
     * @see #buffer(Reader)
     * @since 2.2
     */
    public static BufferedReader toBufferedReader(final Reader reader) {
        return reader instanceof BufferedReader ? (BufferedReader) reader : new BufferedReader(reader);
    }

    
Returns the given reader if it is a BufferedReader, otherwise creates a BufferedReader from the given reader. 
Params:
reader – the reader to wrap or return (not null)
size – the buffer size, if a new BufferedReader is created.
Throws:
NullPointerException – if the input parameter is null
See Also:
buffer(Reader)
Returns:
the given reader or a new BufferedReader for the given reader
Since:
2.5/**
     * Returns the given reader if it is a {@link BufferedReader}, otherwise creates a BufferedReader from the given
     * reader.
     *
     * @param reader the reader to wrap or return (not null)
     * @param size the buffer size, if a new BufferedReader is created.
     * @return the given reader or a new {@link BufferedReader} for the given reader
     * @throws NullPointerException if the input parameter is null
     * @see #buffer(Reader)
     * @since 2.5
     */
    public static BufferedReader toBufferedReader(final Reader reader, final int size) {
        return reader instanceof BufferedReader ? (BufferedReader) reader : new BufferedReader(reader, size);
    }

    
Returns the given reader if it is already a BufferedReader, otherwise creates a BufferedReader from the given reader. 
Params:
reader – the reader to wrap or return (not null)
Throws:
NullPointerException – if the input parameter is null
Returns:
the given reader or a new BufferedReader for the given reader
Since:
2.5/**
     * Returns the given reader if it is already a {@link BufferedReader}, otherwise creates a BufferedReader from
     * the given reader.
     *
     * @param reader the reader to wrap or return (not null)
     * @return the given reader or a new {@link BufferedReader} for the given reader
     * @throws NullPointerException if the input parameter is null
     * @since 2.5
     */
    public static BufferedReader buffer(final Reader reader) {
        return reader instanceof BufferedReader ? (BufferedReader) reader : new BufferedReader(reader);
    }

    
Returns the given reader if it is already a BufferedReader, otherwise creates a BufferedReader from the given reader. 
Params:
reader – the reader to wrap or return (not null)
size – the buffer size, if a new BufferedReader is created.
Throws:
NullPointerException – if the input parameter is null
Returns:
the given reader or a new BufferedReader for the given reader
Since:
2.5/**
     * Returns the given reader if it is already a {@link BufferedReader}, otherwise creates a BufferedReader from the
     * given reader.
     *
     * @param reader the reader to wrap or return (not null)
     * @param size the buffer size, if a new BufferedReader is created.
     * @return the given reader or a new {@link BufferedReader} for the given reader
     * @throws NullPointerException if the input parameter is null
     * @since 2.5
     */
    public static BufferedReader buffer(final Reader reader, final int size) {
        return reader instanceof BufferedReader ? (BufferedReader) reader : new BufferedReader(reader, size);
    }

    
Returns the given Writer if it is already a BufferedWriter, otherwise creates a BufferedWriter from the given Writer. 
Params:
writer – the Writer to wrap or return (not null)
Throws:
NullPointerException – if the input parameter is null
Returns:
the given Writer or a new BufferedWriter for the given Writer
Since:
2.5/**
     * Returns the given Writer if it is already a {@link BufferedWriter}, otherwise creates a BufferedWriter from the
     * given Writer.
     *
     * @param writer the Writer to wrap or return (not null)
     * @return the given Writer or a new {@link BufferedWriter} for the given Writer
     * @throws NullPointerException if the input parameter is null
     * @since 2.5
     */
    public static BufferedWriter buffer(final Writer writer) {
        return writer instanceof BufferedWriter ? (BufferedWriter) writer : new BufferedWriter(writer);
    }

    
Returns the given Writer if it is already a BufferedWriter, otherwise creates a BufferedWriter from the given Writer. 
Params:
writer – the Writer to wrap or return (not null)
size – the buffer size, if a new BufferedWriter is created.
Throws:
NullPointerException – if the input parameter is null
Returns:
the given Writer or a new BufferedWriter for the given Writer
Since:
2.5/**
     * Returns the given Writer if it is already a {@link BufferedWriter}, otherwise creates a BufferedWriter from the
     * given Writer.
     *
     * @param writer the Writer to wrap or return (not null)
     * @param size the buffer size, if a new BufferedWriter is created.
     * @return the given Writer or a new {@link BufferedWriter} for the given Writer
     * @throws NullPointerException if the input parameter is null
     * @since 2.5
     */
    public static BufferedWriter buffer(final Writer writer, final int size) {
        return writer instanceof BufferedWriter ? (BufferedWriter) writer : new BufferedWriter(writer, size);
    }

    
Returns the given OutputStream if it is already a BufferedOutputStream, otherwise creates a BufferedOutputStream from the given OutputStream. 
Params:
outputStream – the OutputStream to wrap or return (not null)
Throws:
NullPointerException – if the input parameter is null
Returns:
the given OutputStream or a new BufferedOutputStream for the given OutputStream
Since:
2.5/**
     * Returns the given OutputStream if it is already a {@link BufferedOutputStream}, otherwise creates a
     * BufferedOutputStream from the given OutputStream.
     *
     * @param outputStream the OutputStream to wrap or return (not null)
     * @return the given OutputStream or a new {@link BufferedOutputStream} for the given OutputStream
     * @throws NullPointerException if the input parameter is null
     * @since 2.5
     */
    public static BufferedOutputStream buffer(final OutputStream outputStream) {
        // reject null early on rather than waiting for IO operation to fail
        if (outputStream == null) { // not checked by BufferedOutputStream
            throw new NullPointerException();
        }
        return outputStream instanceof BufferedOutputStream ?
                (BufferedOutputStream) outputStream : new BufferedOutputStream(outputStream);
    }

    
Returns the given OutputStream if it is already a BufferedOutputStream, otherwise creates a BufferedOutputStream from the given OutputStream. 
Params:
outputStream – the OutputStream to wrap or return (not null)
size – the buffer size, if a new BufferedOutputStream is created.
Throws:
NullPointerException – if the input parameter is null
Returns:
the given OutputStream or a new BufferedOutputStream for the given OutputStream
Since:
2.5/**
     * Returns the given OutputStream if it is already a {@link BufferedOutputStream}, otherwise creates a
     * BufferedOutputStream from the given OutputStream.
     *
     * @param outputStream the OutputStream to wrap or return (not null)
     * @param size the buffer size, if a new BufferedOutputStream is created.
     * @return the given OutputStream or a new {@link BufferedOutputStream} for the given OutputStream
     * @throws NullPointerException if the input parameter is null
     * @since 2.5
     */
    public static BufferedOutputStream buffer(final OutputStream outputStream, final int size) {
        // reject null early on rather than waiting for IO operation to fail
        if (outputStream == null) { // not checked by BufferedOutputStream
            throw new NullPointerException();
        }
        return outputStream instanceof BufferedOutputStream ?
                (BufferedOutputStream) outputStream : new BufferedOutputStream(outputStream, size);
    }

    
Returns the given InputStream if it is already a BufferedInputStream, otherwise creates a BufferedInputStream from the given InputStream. 
Params:
inputStream – the InputStream to wrap or return (not null)
Throws:
NullPointerException – if the input parameter is null
Returns:
the given InputStream or a new BufferedInputStream for the given InputStream
Since:
2.5/**
     * Returns the given InputStream if it is already a {@link BufferedInputStream}, otherwise creates a
     * BufferedInputStream from the given InputStream.
     *
     * @param inputStream the InputStream to wrap or return (not null)
     * @return the given InputStream or a new {@link BufferedInputStream} for the given InputStream
     * @throws NullPointerException if the input parameter is null
     * @since 2.5
     */
    public static BufferedInputStream buffer(final InputStream inputStream) {
        // reject null early on rather than waiting for IO operation to fail
        if (inputStream == null) { // not checked by BufferedInputStream
            throw new NullPointerException();
        }
        return inputStream instanceof BufferedInputStream ?
                (BufferedInputStream) inputStream : new BufferedInputStream(inputStream);
    }

    
Returns the given InputStream if it is already a BufferedInputStream, otherwise creates a BufferedInputStream from the given InputStream. 
Params:
inputStream – the InputStream to wrap or return (not null)
size – the buffer size, if a new BufferedInputStream is created.
Throws:
NullPointerException – if the input parameter is null
Returns:
the given InputStream or a new BufferedInputStream for the given InputStream
Since:
2.5/**
     * Returns the given InputStream if it is already a {@link BufferedInputStream}, otherwise creates a
     * BufferedInputStream from the given InputStream.
     *
     * @param inputStream the InputStream to wrap or return (not null)
     * @param size the buffer size, if a new BufferedInputStream is created.
     * @return the given InputStream or a new {@link BufferedInputStream} for the given InputStream
     * @throws NullPointerException if the input parameter is null
     * @since 2.5
     */
    public static BufferedInputStream buffer(final InputStream inputStream, final int size) {
        // reject null early on rather than waiting for IO operation to fail
        if (inputStream == null) { // not checked by BufferedInputStream
            throw new NullPointerException();
        }
        return inputStream instanceof BufferedInputStream ?
                (BufferedInputStream) inputStream : new BufferedInputStream(inputStream, size);
    }

    // read toByteArray
    //-----------------------------------------------------------------------

    
Gets the contents of an InputStream as a byte[].

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
Params:
input – the InputStream to read from
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the requested byte array/**
     * Gets the contents of an <code>InputStream</code> as a <code>byte[]</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param input the <code>InputStream</code> to read from
     * @return the requested byte array
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     */
    public static byte[] toByteArray(final InputStream input) throws IOException {
        try (final ByteArrayOutputStream output = new ByteArrayOutputStream()) {
            copy(input, output);
            return output.toByteArray();
        }
    }

    
Gets contents of an InputStream as a byte[].
Use this method instead of toByteArray(InputStream)
when InputStream size is known.
NOTE: the method checks that the length can safely be cast to an int without truncation before using toByteArray(InputStream, int) to read into the byte array. (Arrays can have no more than Integer.MAX_VALUE entries anyway) 
Params:
input – the InputStream to read from
size – the size of InputStream
Throws:
IOException –              if an I/O error occurs or InputStream size differ from parameter
size
IllegalArgumentException – if size is less than zero or size is greater than Integer.MAX_VALUE
See Also:
toByteArray(InputStream, int)
Returns:
the requested byte array
Since:
2.1/**
     * Gets contents of an <code>InputStream</code> as a <code>byte[]</code>.
     * Use this method instead of <code>toByteArray(InputStream)</code>
     * when <code>InputStream</code> size is known.
     * <b>NOTE:</b> the method checks that the length can safely be cast to an int without truncation
     * before using {@link IOUtils#toByteArray(java.io.InputStream, int)} to read into the byte array.
     * (Arrays can have no more than Integer.MAX_VALUE entries anyway)
     *
     * @param input the <code>InputStream</code> to read from
     * @param size the size of <code>InputStream</code>
     * @return the requested byte array
     * @throws IOException              if an I/O error occurs or <code>InputStream</code> size differ from parameter
     * size
     * @throws IllegalArgumentException if size is less than zero or size is greater than Integer.MAX_VALUE
     * @see IOUtils#toByteArray(java.io.InputStream, int)
     * @since 2.1
     */
    public static byte[] toByteArray(final InputStream input, final long size) throws IOException {

        if (size > Integer.MAX_VALUE) {
            throw new IllegalArgumentException("Size cannot be greater than Integer max value: " + size);
        }

        return toByteArray(input, (int) size);
    }

    
Gets the contents of an InputStream as a byte[].
Use this method instead of toByteArray(InputStream)
when InputStream size is known
Params:
input – the InputStream to read from
size – the size of InputStream
Throws:
IOException –              if an I/O error occurs or InputStream size differ from parameter
size
IllegalArgumentException – if size is less than zero
Returns:
the requested byte array
Since:
2.1/**
     * Gets the contents of an <code>InputStream</code> as a <code>byte[]</code>.
     * Use this method instead of <code>toByteArray(InputStream)</code>
     * when <code>InputStream</code> size is known
     *
     * @param input the <code>InputStream</code> to read from
     * @param size the size of <code>InputStream</code>
     * @return the requested byte array
     * @throws IOException              if an I/O error occurs or <code>InputStream</code> size differ from parameter
     * size
     * @throws IllegalArgumentException if size is less than zero
     * @since 2.1
     */
    public static byte[] toByteArray(final InputStream input, final int size) throws IOException {

        if (size < 0) {
            throw new IllegalArgumentException("Size must be equal or greater than zero: " + size);
        }

        if (size == 0) {
            return new byte[0];
        }

        final byte[] data = new byte[size];
        int offset = 0;
        int read;

        while (offset < size && (read = input.read(data, offset, size - offset)) != EOF) {
            offset += read;
        }

        if (offset != size) {
            throw new IOException("Unexpected read size. current: " + offset + ", expected: " + size);
        }

        return data;
    }

    
Gets the contents of a Reader as a byte[]
using the default character encoding of the platform.

This method buffers the input internally, so there is no need to use a
BufferedReader.
Params:
input – the Reader to read from
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the requested byte array
Deprecated:
2.5 use toByteArray(Reader, Charset) instead/**
     * Gets the contents of a <code>Reader</code> as a <code>byte[]</code>
     * using the default character encoding of the platform.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     *
     * @param input the <code>Reader</code> to read from
     * @return the requested byte array
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     * @deprecated 2.5 use {@link #toByteArray(Reader, Charset)} instead
     */
    @Deprecated
    public static byte[] toByteArray(final Reader input) throws IOException {
        return toByteArray(input, Charset.defaultCharset());
    }

    
Gets the contents of a Reader as a byte[]
using the specified character encoding.

This method buffers the input internally, so there is no need to use a
BufferedReader.
Params:
input – the Reader to read from
encoding – the encoding to use, null means platform default
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the requested byte array
Since:
2.3/**
     * Gets the contents of a <code>Reader</code> as a <code>byte[]</code>
     * using the specified character encoding.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     *
     * @param input the <code>Reader</code> to read from
     * @param encoding the encoding to use, null means platform default
     * @return the requested byte array
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     * @since 2.3
     */
    public static byte[] toByteArray(final Reader input, final Charset encoding) throws IOException {
        try (final ByteArrayOutputStream output = new ByteArrayOutputStream()) {
            copy(input, output, encoding);
            return output.toByteArray();
        }
    }

    
Gets the contents of a Reader as a byte[]
using the specified character encoding.

Character encoding names can be found at
IANA.

This method buffers the input internally, so there is no need to use a
BufferedReader.
Params:
input – the Reader to read from
encoding – the encoding to use, null means platform default
Throws:
NullPointerException –                         if the input is null
IOException –                                  if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Returns:
the requested byte array
Since:
1.1/**
     * Gets the contents of a <code>Reader</code> as a <code>byte[]</code>
     * using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     *
     * @param input the <code>Reader</code> to read from
     * @param encoding the encoding to use, null means platform default
     * @return the requested byte array
     * @throws NullPointerException                         if the input is null
     * @throws IOException                                  if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 1.1
     */
    public static byte[] toByteArray(final Reader input, final String encoding) throws IOException {
        return toByteArray(input, Charsets.toCharset(encoding));
    }

    
Gets the contents of a String as a byte[]
using the default character encoding of the platform.
 This is the same as String.getBytes(). 
Params:
input – the String to convert
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs (never occurs)
Returns:
the requested byte array
Deprecated:
2.5 Use String.getBytes() instead/**
     * Gets the contents of a <code>String</code> as a <code>byte[]</code>
     * using the default character encoding of the platform.
     * <p>
     * This is the same as {@link String#getBytes()}.
     *
     * @param input the <code>String</code> to convert
     * @return the requested byte array
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs (never occurs)
     * @deprecated 2.5 Use {@link String#getBytes()} instead
     */
    @Deprecated
    public static byte[] toByteArray(final String input) throws IOException {
        // make explicit the use of the default charset
        return input.getBytes(Charset.defaultCharset());
    }

    
Gets the contents of a URI as a byte[].
Params:
uri – the URI to read
Throws:
NullPointerException – if the uri is null
IOException –          if an I/O exception occurs
Returns:
the requested byte array
Since:
2.4/**
     * Gets the contents of a <code>URI</code> as a <code>byte[]</code>.
     *
     * @param uri the <code>URI</code> to read
     * @return the requested byte array
     * @throws NullPointerException if the uri is null
     * @throws IOException          if an I/O exception occurs
     * @since 2.4
     */
    public static byte[] toByteArray(final URI uri) throws IOException {
        return IOUtils.toByteArray(uri.toURL());
    }

    
Gets the contents of a URL as a byte[].
Params:
url – the URL to read
Throws:
NullPointerException – if the input is null
IOException –          if an I/O exception occurs
Returns:
the requested byte array
Since:
2.4/**
     * Gets the contents of a <code>URL</code> as a <code>byte[]</code>.
     *
     * @param url the <code>URL</code> to read
     * @return the requested byte array
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O exception occurs
     * @since 2.4
     */
    public static byte[] toByteArray(final URL url) throws IOException {
        final URLConnection conn = url.openConnection();
        try {
            return IOUtils.toByteArray(conn);
        } finally {
            close(conn);
        }
    }

    
Gets the contents of a URLConnection as a byte[].
Params:
urlConn – the URLConnection to read
Throws:
NullPointerException – if the urlConn is null
IOException –          if an I/O exception occurs
Returns:
the requested byte array
Since:
2.4/**
     * Gets the contents of a <code>URLConnection</code> as a <code>byte[]</code>.
     *
     * @param urlConn the <code>URLConnection</code> to read
     * @return the requested byte array
     * @throws NullPointerException if the urlConn is null
     * @throws IOException          if an I/O exception occurs
     * @since 2.4
     */
    public static byte[] toByteArray(final URLConnection urlConn) throws IOException {
        try (InputStream inputStream = urlConn.getInputStream()) {
            return IOUtils.toByteArray(inputStream);
        }
    }

    // read char[]
    //-----------------------------------------------------------------------

    
Gets the contents of an InputStream as a character array
using the default character encoding of the platform.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
Params:
is – the InputStream to read from
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the requested character array
Since:
1.1
Deprecated:
2.5 use toCharArray(InputStream, Charset) instead/**
     * Gets the contents of an <code>InputStream</code> as a character array
     * using the default character encoding of the platform.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param is the <code>InputStream</code> to read from
     * @return the requested character array
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     * @deprecated 2.5 use {@link #toCharArray(InputStream, Charset)} instead
     */
    @Deprecated
    public static char[] toCharArray(final InputStream is) throws IOException {
        return toCharArray(is, Charset.defaultCharset());
    }

    
Gets the contents of an InputStream as a character array
using the specified character encoding.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
Params:
is – the InputStream to read from
encoding – the encoding to use, null means platform default
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the requested character array
Since:
2.3/**
     * Gets the contents of an <code>InputStream</code> as a character array
     * using the specified character encoding.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param is the <code>InputStream</code> to read from
     * @param encoding the encoding to use, null means platform default
     * @return the requested character array
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     * @since 2.3
     */
    public static char[] toCharArray(final InputStream is, final Charset encoding)
            throws IOException {
        final CharArrayWriter output = new CharArrayWriter();
        copy(is, output, encoding);
        return output.toCharArray();
    }

    
Gets the contents of an InputStream as a character array
using the specified character encoding.

Character encoding names can be found at
IANA.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
Params:
is – the InputStream to read from
encoding – the encoding to use, null means platform default
Throws:
NullPointerException –                         if the input is null
IOException –                                  if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Returns:
the requested character array
Since:
1.1/**
     * Gets the contents of an <code>InputStream</code> as a character array
     * using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param is the <code>InputStream</code> to read from
     * @param encoding the encoding to use, null means platform default
     * @return the requested character array
     * @throws NullPointerException                         if the input is null
     * @throws IOException                                  if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 1.1
     */
    public static char[] toCharArray(final InputStream is, final String encoding) throws IOException {
        return toCharArray(is, Charsets.toCharset(encoding));
    }

    
Gets the contents of a Reader as a character array.

This method buffers the input internally, so there is no need to use a
BufferedReader.
Params:
input – the Reader to read from
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the requested character array
Since:
1.1/**
     * Gets the contents of a <code>Reader</code> as a character array.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     *
     * @param input the <code>Reader</code> to read from
     * @return the requested character array
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     */
    public static char[] toCharArray(final Reader input) throws IOException {
        final CharArrayWriter sw = new CharArrayWriter();
        copy(input, sw);
        return sw.toCharArray();
    }

    // read toString
    //-----------------------------------------------------------------------

    
Gets the contents of an InputStream as a String
using the default character encoding of the platform.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
Params:
input – the InputStream to read from
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the requested String
Deprecated:
2.5 use toString(InputStream, Charset) instead/**
     * Gets the contents of an <code>InputStream</code> as a String
     * using the default character encoding of the platform.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param input the <code>InputStream</code> to read from
     * @return the requested String
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     * @deprecated 2.5 use {@link #toString(InputStream, Charset)} instead
     */
    @Deprecated
    public static String toString(final InputStream input) throws IOException {
        return toString(input, Charset.defaultCharset());
    }

    
Gets the contents of an InputStream as a String
using the specified character encoding.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.

Params:
input – the InputStream to read from
encoding – the encoding to use, null means platform default
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the requested String
Since:
2.3/**
     * Gets the contents of an <code>InputStream</code> as a String
     * using the specified character encoding.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * </p>
     *
     * @param input the <code>InputStream</code> to read from
     * @param encoding the encoding to use, null means platform default
     * @return the requested String
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     * @since 2.3
     */
    public static String toString(final InputStream input, final Charset encoding) throws IOException {
        try (final StringBuilderWriter sw = new StringBuilderWriter()) {
            copy(input, sw, encoding);
            return sw.toString();
        }
    }

    
Gets the contents of an InputStream as a String
using the specified character encoding.

Character encoding names can be found at
IANA.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
Params:
input – the InputStream to read from
encoding – the encoding to use, null means platform default
Throws:
NullPointerException –                         if the input is null
IOException –                                  if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Returns:
the requested String/**
     * Gets the contents of an <code>InputStream</code> as a String
     * using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param input the <code>InputStream</code> to read from
     * @param encoding the encoding to use, null means platform default
     * @return the requested String
     * @throws NullPointerException                         if the input is null
     * @throws IOException                                  if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     */
    public static String toString(final InputStream input, final String encoding)
            throws IOException {
        return toString(input, Charsets.toCharset(encoding));
    }

    
Gets the contents of a Reader as a String.

This method buffers the input internally, so there is no need to use a
BufferedReader.
Params:
input – the Reader to read from
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the requested String/**
     * Gets the contents of a <code>Reader</code> as a String.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     *
     * @param input the <code>Reader</code> to read from
     * @return the requested String
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     */
    public static String toString(final Reader input) throws IOException {
        try (final StringBuilderWriter sw = new StringBuilderWriter()) {
            copy(input, sw);
            return sw.toString();
        }
    }

    
Gets the contents at the given URI.
Params:
uri – The URI source.
Throws:
IOException – if an I/O exception occurs.
Returns:
The contents of the URL as a String.
Since:
2.1
Deprecated:
2.5 use toString(URI, Charset) instead/**
     * Gets the contents at the given URI.
     *
     * @param uri The URI source.
     * @return The contents of the URL as a String.
     * @throws IOException if an I/O exception occurs.
     * @since 2.1
     * @deprecated 2.5 use {@link #toString(URI, Charset)} instead
     */
    @Deprecated
    public static String toString(final URI uri) throws IOException {
        return toString(uri, Charset.defaultCharset());
    }

    
Gets the contents at the given URI.
Params:
uri – The URI source.
encoding – The encoding name for the URL contents.
Throws:
IOException – if an I/O exception occurs.
Returns:
The contents of the URL as a String.
Since:
2.3./**
     * Gets the contents at the given URI.
     *
     * @param uri The URI source.
     * @param encoding The encoding name for the URL contents.
     * @return The contents of the URL as a String.
     * @throws IOException if an I/O exception occurs.
     * @since 2.3.
     */
    public static String toString(final URI uri, final Charset encoding) throws IOException {
        return toString(uri.toURL(), Charsets.toCharset(encoding));
    }

    
Gets the contents at the given URI.
Params:
uri – The URI source.
encoding – The encoding name for the URL contents.
Throws:
IOException –                                  if an I/O exception occurs.
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Returns:
The contents of the URL as a String.
Since:
2.1/**
     * Gets the contents at the given URI.
     *
     * @param uri The URI source.
     * @param encoding The encoding name for the URL contents.
     * @return The contents of the URL as a String.
     * @throws IOException                                  if an I/O exception occurs.
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 2.1
     */
    public static String toString(final URI uri, final String encoding) throws IOException {
        return toString(uri, Charsets.toCharset(encoding));
    }

    
Gets the contents at the given URL.
Params:
url – The URL source.
Throws:
IOException – if an I/O exception occurs.
Returns:
The contents of the URL as a String.
Since:
2.1
Deprecated:
2.5 use toString(URL, Charset) instead/**
     * Gets the contents at the given URL.
     *
     * @param url The URL source.
     * @return The contents of the URL as a String.
     * @throws IOException if an I/O exception occurs.
     * @since 2.1
     * @deprecated 2.5 use {@link #toString(URL, Charset)} instead
     */
    @Deprecated
    public static String toString(final URL url) throws IOException {
        return toString(url, Charset.defaultCharset());
    }

    
Gets the contents at the given URL.
Params:
url – The URL source.
encoding – The encoding name for the URL contents.
Throws:
IOException – if an I/O exception occurs.
Returns:
The contents of the URL as a String.
Since:
2.3/**
     * Gets the contents at the given URL.
     *
     * @param url The URL source.
     * @param encoding The encoding name for the URL contents.
     * @return The contents of the URL as a String.
     * @throws IOException if an I/O exception occurs.
     * @since 2.3
     */
    public static String toString(final URL url, final Charset encoding) throws IOException {
        try (InputStream inputStream = url.openStream()) {
            return toString(inputStream, encoding);
        }
    }

    
Gets the contents at the given URL.
Params:
url – The URL source.
encoding – The encoding name for the URL contents.
Throws:
IOException –                                  if an I/O exception occurs.
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Returns:
The contents of the URL as a String.
Since:
2.1/**
     * Gets the contents at the given URL.
     *
     * @param url The URL source.
     * @param encoding The encoding name for the URL contents.
     * @return The contents of the URL as a String.
     * @throws IOException                                  if an I/O exception occurs.
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 2.1
     */
    public static String toString(final URL url, final String encoding) throws IOException {
        return toString(url, Charsets.toCharset(encoding));
    }

    
Gets the contents of a byte[] as a String
using the default character encoding of the platform.
Params:
input – the byte array to read from
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs (never occurs)
Returns:
the requested String
Deprecated:
2.5 Use String(byte[]) instead/**
     * Gets the contents of a <code>byte[]</code> as a String
     * using the default character encoding of the platform.
     *
     * @param input the byte array to read from
     * @return the requested String
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs (never occurs)
     * @deprecated 2.5 Use {@link String#String(byte[])} instead
     */
    @Deprecated
    public static String toString(final byte[] input) throws IOException {
        // make explicit the use of the default charset
        return new String(input, Charset.defaultCharset());
    }

    
Gets the contents of a byte[] as a String
using the specified character encoding.

Character encoding names can be found at
IANA.
Params:
input – the byte array to read from
encoding – the encoding to use, null means platform default
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs (never occurs)
Returns:
the requested String/**
     * Gets the contents of a <code>byte[]</code> as a String
     * using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     *
     * @param input the byte array to read from
     * @param encoding the encoding to use, null means platform default
     * @return the requested String
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs (never occurs)
     */
    public static String toString(final byte[] input, final String encoding) throws IOException {
        return new String(input, Charsets.toCharset(encoding));
    }

    // resources
    //-----------------------------------------------------------------------

    
Gets the contents of a classpath resource as a String using the
specified character encoding.

It is expected the given name to be absolute. The
behavior is not well-defined otherwise.

Params:
name –     name of the desired resource
encoding – the encoding to use, null means platform default
Throws:
IOException – if an I/O error occurs
Returns:
the requested String
Since:
2.6/**
     * Gets the contents of a classpath resource as a String using the
     * specified character encoding.
     *
     * <p>
     * It is expected the given <code>name</code> to be absolute. The
     * behavior is not well-defined otherwise.
     * </p>
     *
     * @param name     name of the desired resource
     * @param encoding the encoding to use, null means platform default
     * @return the requested String
     * @throws IOException if an I/O error occurs
     *
     * @since 2.6
     */
    public static String resourceToString(final String name, final Charset encoding) throws IOException {
        return resourceToString(name, encoding, null);
    }

    
Gets the contents of a classpath resource as a String using the
specified character encoding.

It is expected the given name to be absolute. The
behavior is not well-defined otherwise.

Params:
name –     name of the desired resource
encoding – the encoding to use, null means platform default
classLoader – the class loader that the resolution of the resource is delegated to
Throws:
IOException – if an I/O error occurs
Returns:
the requested String
Since:
2.6/**
     * Gets the contents of a classpath resource as a String using the
     * specified character encoding.
     *
     * <p>
     * It is expected the given <code>name</code> to be absolute. The
     * behavior is not well-defined otherwise.
     * </p>
     *
     * @param name     name of the desired resource
     * @param encoding the encoding to use, null means platform default
     * @param classLoader the class loader that the resolution of the resource is delegated to
     * @return the requested String
     * @throws IOException if an I/O error occurs
     *
     * @since 2.6
     */
    public static String resourceToString(final String name, final Charset encoding, final ClassLoader classLoader) throws IOException {
        return toString(resourceToURL(name, classLoader), encoding);
    }

    
Gets the contents of a classpath resource as a byte array.

It is expected the given name to be absolute. The
behavior is not well-defined otherwise.

Params:
name – name of the desired resource
Throws:
IOException – if an I/O error occurs
Returns:
the requested byte array
Since:
2.6/**
     * Gets the contents of a classpath resource as a byte array.
     *
     * <p>
     * It is expected the given <code>name</code> to be absolute. The
     * behavior is not well-defined otherwise.
     * </p>
     *
     * @param name name of the desired resource
     * @return the requested byte array
     * @throws IOException if an I/O error occurs
     *
     * @since 2.6
     */
    public static byte[] resourceToByteArray(final String name) throws IOException {
        return resourceToByteArray(name, null);
    }

    
Gets the contents of a classpath resource as a byte array.

It is expected the given name to be absolute. The
behavior is not well-defined otherwise.

Params:
name – name of the desired resource
classLoader – the class loader that the resolution of the resource is delegated to
Throws:
IOException – if an I/O error occurs
Returns:
the requested byte array
Since:
2.6/**
     * Gets the contents of a classpath resource as a byte array.
     *
     * <p>
     * It is expected the given <code>name</code> to be absolute. The
     * behavior is not well-defined otherwise.
     * </p>
     *
     * @param name name of the desired resource
     * @param classLoader the class loader that the resolution of the resource is delegated to
     * @return the requested byte array
     * @throws IOException if an I/O error occurs
     *
     * @since 2.6
     */
    public static byte[] resourceToByteArray(final String name, final ClassLoader classLoader) throws IOException {
        return toByteArray(resourceToURL(name, classLoader));
    }

    
Gets a URL pointing to the given classpath resource.

It is expected the given name to be absolute. The
behavior is not well-defined otherwise.

Params:
name – name of the desired resource
Throws:
IOException – if an I/O error occurs
Returns:
the requested URL
Since:
2.6/**
     * Gets a URL pointing to the given classpath resource.
     *
     * <p>
     * It is expected the given <code>name</code> to be absolute. The
     * behavior is not well-defined otherwise.
     * </p>
     *
     * @param name name of the desired resource
     * @return the requested URL
     * @throws IOException if an I/O error occurs
     *
     * @since 2.6
     */
    public static URL resourceToURL(final String name) throws IOException {
        return resourceToURL(name, null);
    }

    
Gets a URL pointing to the given classpath resource.

It is expected the given name to be absolute. The
behavior is not well-defined otherwise.

Params:
name –        name of the desired resource
classLoader – the class loader that the resolution of the resource is delegated to
Throws:
IOException – if an I/O error occurs
Returns:
the requested URL
Since:
2.6/**
     * Gets a URL pointing to the given classpath resource.
     *
     * <p>
     * It is expected the given <code>name</code> to be absolute. The
     * behavior is not well-defined otherwise.
     * </p>
     *
     * @param name        name of the desired resource
     * @param classLoader the class loader that the resolution of the resource is delegated to
     * @return the requested URL
     * @throws IOException if an I/O error occurs
     *
     * @since 2.6
     */
    public static URL resourceToURL(final String name, final ClassLoader classLoader) throws IOException {
        // What about the thread context class loader?
        // What about the system class loader?
        final URL resource = classLoader == null ? IOUtils.class.getResource(name) : classLoader.getResource(name);

        if (resource == null) {
            throw new IOException("Resource not found: " + name);
        }

        return resource;
    }

    // readLines
    //-----------------------------------------------------------------------

    
Gets the contents of an InputStream as a list of Strings,
one entry per line, using the default character encoding of the platform.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
Params:
input – the InputStream to read from, not null
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the list of Strings, never null
Since:
1.1
Deprecated:
2.5 use readLines(InputStream, Charset) instead/**
     * Gets the contents of an <code>InputStream</code> as a list of Strings,
     * one entry per line, using the default character encoding of the platform.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param input the <code>InputStream</code> to read from, not null
     * @return the list of Strings, never null
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     * @deprecated 2.5 use {@link #readLines(InputStream, Charset)} instead
     */
    @Deprecated
    public static List<String> readLines(final InputStream input) throws IOException {
        return readLines(input, Charset.defaultCharset());
    }

    
Gets the contents of an InputStream as a list of Strings,
one entry per line, using the specified character encoding.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
Params:
input – the InputStream to read from, not null
encoding – the encoding to use, null means platform default
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the list of Strings, never null
Since:
2.3/**
     * Gets the contents of an <code>InputStream</code> as a list of Strings,
     * one entry per line, using the specified character encoding.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param input the <code>InputStream</code> to read from, not null
     * @param encoding the encoding to use, null means platform default
     * @return the list of Strings, never null
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     * @since 2.3
     */
    public static List<String> readLines(final InputStream input, final Charset encoding) throws IOException {
        final InputStreamReader reader = new InputStreamReader(input, Charsets.toCharset(encoding));
        return readLines(reader);
    }

    
Gets the contents of an InputStream as a list of Strings,
one entry per line, using the specified character encoding.

Character encoding names can be found at
IANA.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
Params:
input – the InputStream to read from, not null
encoding – the encoding to use, null means platform default
Throws:
NullPointerException –                         if the input is null
IOException –                                  if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Returns:
the list of Strings, never null
Since:
1.1/**
     * Gets the contents of an <code>InputStream</code> as a list of Strings,
     * one entry per line, using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param input the <code>InputStream</code> to read from, not null
     * @param encoding the encoding to use, null means platform default
     * @return the list of Strings, never null
     * @throws NullPointerException                         if the input is null
     * @throws IOException                                  if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 1.1
     */
    public static List<String> readLines(final InputStream input, final String encoding) throws IOException {
        return readLines(input, Charsets.toCharset(encoding));
    }

    
Gets the contents of a Reader as a list of Strings,
one entry per line.

This method buffers the input internally, so there is no need to use a
BufferedReader.
Params:
input – the Reader to read from, not null
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Returns:
the list of Strings, never null
Since:
1.1/**
     * Gets the contents of a <code>Reader</code> as a list of Strings,
     * one entry per line.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     *
     * @param input the <code>Reader</code> to read from, not null
     * @return the list of Strings, never null
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     */
    public static List<String> readLines(final Reader input) throws IOException {
        final BufferedReader reader = toBufferedReader(input);
        final List<String> list = new ArrayList<>();
        String line = reader.readLine();
        while (line != null) {
            list.add(line);
            line = reader.readLine();
        }
        return list;
    }

    // lineIterator
    //-----------------------------------------------------------------------

    
Returns an Iterator for the lines in a Reader.

LineIterator holds a reference to the open
Reader specified here. When you have finished with the iterator you should close the reader to free internal resources. This can be done by closing the reader directly, or by calling LineIterator.close() or LineIterator.closeQuietly(LineIterator). 

The recommended usage pattern is:
try {
  LineIterator it = IOUtils.lineIterator(reader);
  while (it.hasNext()) {
    String line = it.nextLine();
    /// do something with line
  }
} finally {
  IOUtils.closeQuietly(reader);
}

Params:
reader – the Reader to read from, not null
Throws:
IllegalArgumentException – if the reader is null
Returns:
an Iterator of the lines in the reader, never null
Since:
1.2/**
     * Returns an Iterator for the lines in a <code>Reader</code>.
     * <p>
     * <code>LineIterator</code> holds a reference to the open
     * <code>Reader</code> specified here. When you have finished with the
     * iterator you should close the reader to free internal resources.
     * This can be done by closing the reader directly, or by calling
     * {@link LineIterator#close()} or {@link LineIterator#closeQuietly(LineIterator)}.
     * <p>
     * The recommended usage pattern is:
     * <pre>
     * try {
     *   LineIterator it = IOUtils.lineIterator(reader);
     *   while (it.hasNext()) {
     *     String line = it.nextLine();
     *     /// do something with line
     *   }
     * } finally {
     *   IOUtils.closeQuietly(reader);
     * }
     * </pre>
     *
     * @param reader the <code>Reader</code> to read from, not null
     * @return an Iterator of the lines in the reader, never null
     * @throws IllegalArgumentException if the reader is null
     * @since 1.2
     */
    public static LineIterator lineIterator(final Reader reader) {
        return new LineIterator(reader);
    }

    
Returns an Iterator for the lines in an InputStream, using
the character encoding specified (or default encoding if null).

LineIterator holds a reference to the open
InputStream specified here. When you have finished with the iterator you should close the stream to free internal resources. This can be done by closing the stream directly, or by calling LineIterator.close() or LineIterator.closeQuietly(LineIterator). 

The recommended usage pattern is:
try {
  LineIterator it = IOUtils.lineIterator(stream, charset);
  while (it.hasNext()) {
    String line = it.nextLine();
    /// do something with line
  }
} finally {
  IOUtils.closeQuietly(stream);
}

Params:
input – the InputStream to read from, not null
encoding – the encoding to use, null means platform default
Throws:
IllegalArgumentException – if the input is null
IOException –              if an I/O error occurs, such as if the encoding is invalid
Returns:
an Iterator of the lines in the reader, never null
Since:
2.3/**
     * Returns an Iterator for the lines in an <code>InputStream</code>, using
     * the character encoding specified (or default encoding if null).
     * <p>
     * <code>LineIterator</code> holds a reference to the open
     * <code>InputStream</code> specified here. When you have finished with
     * the iterator you should close the stream to free internal resources.
     * This can be done by closing the stream directly, or by calling
     * {@link LineIterator#close()} or {@link LineIterator#closeQuietly(LineIterator)}.
     * <p>
     * The recommended usage pattern is:
     * <pre>
     * try {
     *   LineIterator it = IOUtils.lineIterator(stream, charset);
     *   while (it.hasNext()) {
     *     String line = it.nextLine();
     *     /// do something with line
     *   }
     * } finally {
     *   IOUtils.closeQuietly(stream);
     * }
     * </pre>
     *
     * @param input the <code>InputStream</code> to read from, not null
     * @param encoding the encoding to use, null means platform default
     * @return an Iterator of the lines in the reader, never null
     * @throws IllegalArgumentException if the input is null
     * @throws IOException              if an I/O error occurs, such as if the encoding is invalid
     * @since 2.3
     */
    public static LineIterator lineIterator(final InputStream input, final Charset encoding) throws IOException {
        return new LineIterator(new InputStreamReader(input, Charsets.toCharset(encoding)));
    }

    
Returns an Iterator for the lines in an InputStream, using
the character encoding specified (or default encoding if null).

LineIterator holds a reference to the open
InputStream specified here. When you have finished with the iterator you should close the stream to free internal resources. This can be done by closing the stream directly, or by calling LineIterator.close() or LineIterator.closeQuietly(LineIterator). 

The recommended usage pattern is:
try {
  LineIterator it = IOUtils.lineIterator(stream, "UTF-8");
  while (it.hasNext()) {
    String line = it.nextLine();
    /// do something with line
  }
} finally {
  IOUtils.closeQuietly(stream);
}

Params:
input – the InputStream to read from, not null
encoding – the encoding to use, null means platform default
Throws:
IllegalArgumentException –                     if the input is null
IOException –                                  if an I/O error occurs, such as if the encoding is invalid
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Returns:
an Iterator of the lines in the reader, never null
Since:
1.2/**
     * Returns an Iterator for the lines in an <code>InputStream</code>, using
     * the character encoding specified (or default encoding if null).
     * <p>
     * <code>LineIterator</code> holds a reference to the open
     * <code>InputStream</code> specified here. When you have finished with
     * the iterator you should close the stream to free internal resources.
     * This can be done by closing the stream directly, or by calling
     * {@link LineIterator#close()} or {@link LineIterator#closeQuietly(LineIterator)}.
     * <p>
     * The recommended usage pattern is:
     * <pre>
     * try {
     *   LineIterator it = IOUtils.lineIterator(stream, "UTF-8");
     *   while (it.hasNext()) {
     *     String line = it.nextLine();
     *     /// do something with line
     *   }
     * } finally {
     *   IOUtils.closeQuietly(stream);
     * }
     * </pre>
     *
     * @param input the <code>InputStream</code> to read from, not null
     * @param encoding the encoding to use, null means platform default
     * @return an Iterator of the lines in the reader, never null
     * @throws IllegalArgumentException                     if the input is null
     * @throws IOException                                  if an I/O error occurs, such as if the encoding is invalid
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 1.2
     */
    public static LineIterator lineIterator(final InputStream input, final String encoding) throws IOException {
        return lineIterator(input, Charsets.toCharset(encoding));
    }

    //-----------------------------------------------------------------------

    
Converts the specified CharSequence to an input stream, encoded as bytes
using the default character encoding of the platform.
Params:
input – the CharSequence to convert
Returns:
an input stream
Since:
2.0
Deprecated:
2.5 use toInputStream(CharSequence, Charset) instead/**
     * Converts the specified CharSequence to an input stream, encoded as bytes
     * using the default character encoding of the platform.
     *
     * @param input the CharSequence to convert
     * @return an input stream
     * @since 2.0
     * @deprecated 2.5 use {@link #toInputStream(CharSequence, Charset)} instead
     */
    @Deprecated
    public static InputStream toInputStream(final CharSequence input) {
        return toInputStream(input, Charset.defaultCharset());
    }

    
Converts the specified CharSequence to an input stream, encoded as bytes
using the specified character encoding.
Params:
input – the CharSequence to convert
encoding – the encoding to use, null means platform default
Returns:
an input stream
Since:
2.3/**
     * Converts the specified CharSequence to an input stream, encoded as bytes
     * using the specified character encoding.
     *
     * @param input the CharSequence to convert
     * @param encoding the encoding to use, null means platform default
     * @return an input stream
     * @since 2.3
     */
    public static InputStream toInputStream(final CharSequence input, final Charset encoding) {
        return toInputStream(input.toString(), encoding);
    }

    
Converts the specified CharSequence to an input stream, encoded as bytes
using the specified character encoding.

Character encoding names can be found at
IANA.
Params:
input – the CharSequence to convert
encoding – the encoding to use, null means platform default
Throws:
IOException –                                  if the encoding is invalid
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Returns:
an input stream
Since:
2.0/**
     * Converts the specified CharSequence to an input stream, encoded as bytes
     * using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     *
     * @param input the CharSequence to convert
     * @param encoding the encoding to use, null means platform default
     * @return an input stream
     * @throws IOException                                  if the encoding is invalid
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 2.0
     */
    public static InputStream toInputStream(final CharSequence input, final String encoding) throws IOException {
        return toInputStream(input, Charsets.toCharset(encoding));
    }

    //-----------------------------------------------------------------------

    
Converts the specified string to an input stream, encoded as bytes
using the default character encoding of the platform.
Params:
input – the string to convert
Returns:
an input stream
Since:
1.1
Deprecated:
2.5 use toInputStream(String, Charset) instead/**
     * Converts the specified string to an input stream, encoded as bytes
     * using the default character encoding of the platform.
     *
     * @param input the string to convert
     * @return an input stream
     * @since 1.1
     * @deprecated 2.5 use {@link #toInputStream(String, Charset)} instead
     */
    @Deprecated
    public static InputStream toInputStream(final String input) {
        return toInputStream(input, Charset.defaultCharset());
    }

    
Converts the specified string to an input stream, encoded as bytes
using the specified character encoding.
Params:
input – the string to convert
encoding – the encoding to use, null means platform default
Returns:
an input stream
Since:
2.3/**
     * Converts the specified string to an input stream, encoded as bytes
     * using the specified character encoding.
     *
     * @param input the string to convert
     * @param encoding the encoding to use, null means platform default
     * @return an input stream
     * @since 2.3
     */
    public static InputStream toInputStream(final String input, final Charset encoding) {
        return new ByteArrayInputStream(input.getBytes(Charsets.toCharset(encoding)));
    }

    
Converts the specified string to an input stream, encoded as bytes
using the specified character encoding.

Character encoding names can be found at
IANA.
Params:
input – the string to convert
encoding – the encoding to use, null means platform default
Throws:
IOException –                                  if the encoding is invalid
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Returns:
an input stream
Since:
1.1/**
     * Converts the specified string to an input stream, encoded as bytes
     * using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     *
     * @param input the string to convert
     * @param encoding the encoding to use, null means platform default
     * @return an input stream
     * @throws IOException                                  if the encoding is invalid
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 1.1
     */
    public static InputStream toInputStream(final String input, final String encoding) throws IOException {
        final byte[] bytes = input.getBytes(Charsets.toCharset(encoding));
        return new ByteArrayInputStream(bytes);
    }

    // write byte[]
    //-----------------------------------------------------------------------

    
Writes bytes from a byte[] to an OutputStream.
Params:
data – the byte array to write, do not modify during output,
null ignored
output – the OutputStream to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
1.1/**
     * Writes bytes from a <code>byte[]</code> to an <code>OutputStream</code>.
     *
     * @param data the byte array to write, do not modify during output,
     * null ignored
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     */
    public static void write(final byte[] data, final OutputStream output)
            throws IOException {
        if (data != null) {
            output.write(data);
        }
    }

    
Writes bytes from a byte[] to an OutputStream using chunked writes.
This is intended for writing very large byte arrays which might otherwise cause excessive
memory usage if the native code has to allocate a copy.
Params:
data – the byte array to write, do not modify during output,
null ignored
output – the OutputStream to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
2.5/**
     * Writes bytes from a <code>byte[]</code> to an <code>OutputStream</code> using chunked writes.
     * This is intended for writing very large byte arrays which might otherwise cause excessive
     * memory usage if the native code has to allocate a copy.
     *
     * @param data the byte array to write, do not modify during output,
     * null ignored
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.5
     */
    public static void writeChunked(final byte[] data, final OutputStream output)
            throws IOException {
        if (data != null) {
            int bytes = data.length;
            int offset = 0;
            while (bytes > 0) {
                final int chunk = Math.min(bytes, DEFAULT_BUFFER_SIZE);
                output.write(data, offset, chunk);
                bytes -= chunk;
                offset += chunk;
            }
        }
    }

    
Writes bytes from a byte[] to chars on a Writer
using the default character encoding of the platform.
 This method uses String(byte[]). 
Params:
data – the byte array to write, do not modify during output,
null ignored
output – the Writer to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
1.1
Deprecated:
2.5 use write(byte[], Writer, Charset) instead/**
     * Writes bytes from a <code>byte[]</code> to chars on a <code>Writer</code>
     * using the default character encoding of the platform.
     * <p>
     * This method uses {@link String#String(byte[])}.
     *
     * @param data the byte array to write, do not modify during output,
     * null ignored
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     * @deprecated 2.5 use {@link #write(byte[], Writer, Charset)} instead
     */
    @Deprecated
    public static void write(final byte[] data, final Writer output) throws IOException {
        write(data, output, Charset.defaultCharset());
    }

    
Writes bytes from a byte[] to chars on a Writer
using the specified character encoding.
 This method uses String(byte[], String). 
Params:
data – the byte array to write, do not modify during output,
null ignored
output – the Writer to write to
encoding – the encoding to use, null means platform default
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
2.3/**
     * Writes bytes from a <code>byte[]</code> to chars on a <code>Writer</code>
     * using the specified character encoding.
     * <p>
     * This method uses {@link String#String(byte[], String)}.
     *
     * @param data the byte array to write, do not modify during output,
     * null ignored
     * @param output the <code>Writer</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.3
     */
    public static void write(final byte[] data, final Writer output, final Charset encoding) throws IOException {
        if (data != null) {
            output.write(new String(data, Charsets.toCharset(encoding)));
        }
    }

    
Writes bytes from a byte[] to chars on a Writer
using the specified character encoding.

Character encoding names can be found at
IANA.
 This method uses String(byte[], String). 
Params:
data – the byte array to write, do not modify during output,
null ignored
output – the Writer to write to
encoding – the encoding to use, null means platform default
Throws:
NullPointerException –                         if output is null
IOException –                                  if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Since:
1.1/**
     * Writes bytes from a <code>byte[]</code> to chars on a <code>Writer</code>
     * using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link String#String(byte[], String)}.
     *
     * @param data the byte array to write, do not modify during output,
     * null ignored
     * @param output the <code>Writer</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException                         if output is null
     * @throws IOException                                  if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 1.1
     */
    public static void write(final byte[] data, final Writer output, final String encoding) throws IOException {
        write(data, output, Charsets.toCharset(encoding));
    }

    // write char[]
    //-----------------------------------------------------------------------

    
Writes chars from a char[] to a Writer
Params:
data – the char array to write, do not modify during output,
null ignored
output – the Writer to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
1.1/**
     * Writes chars from a <code>char[]</code> to a <code>Writer</code>
     *
     * @param data the char array to write, do not modify during output,
     * null ignored
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     */
    public static void write(final char[] data, final Writer output) throws IOException {
        if (data != null) {
            output.write(data);
        }
    }

    
Writes chars from a char[] to a Writer using chunked writes.
This is intended for writing very large byte arrays which might otherwise cause excessive
memory usage if the native code has to allocate a copy.
Params:
data – the char array to write, do not modify during output,
null ignored
output – the Writer to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
2.5/**
     * Writes chars from a <code>char[]</code> to a <code>Writer</code> using chunked writes.
     * This is intended for writing very large byte arrays which might otherwise cause excessive
     * memory usage if the native code has to allocate a copy.
     *
     * @param data the char array to write, do not modify during output,
     * null ignored
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.5
     */
    public static void writeChunked(final char[] data, final Writer output) throws IOException {
        if (data != null) {
            int bytes = data.length;
            int offset = 0;
            while (bytes > 0) {
                final int chunk = Math.min(bytes, DEFAULT_BUFFER_SIZE);
                output.write(data, offset, chunk);
                bytes -= chunk;
                offset += chunk;
            }
        }
    }

    
Writes chars from a char[] to bytes on an
OutputStream.
 This method uses String(char[]) and String.getBytes(). 
Params:
data – the char array to write, do not modify during output,
null ignored
output – the OutputStream to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
1.1
Deprecated:
2.5 use write(char[], OutputStream, Charset) instead/**
     * Writes chars from a <code>char[]</code> to bytes on an
     * <code>OutputStream</code>.
     * <p>
     * This method uses {@link String#String(char[])} and
     * {@link String#getBytes()}.
     *
     * @param data the char array to write, do not modify during output,
     * null ignored
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     * @deprecated 2.5 use {@link #write(char[], OutputStream, Charset)} instead
     */
    @Deprecated
    public static void write(final char[] data, final OutputStream output)
            throws IOException {
        write(data, output, Charset.defaultCharset());
    }

    
Writes chars from a char[] to bytes on an
OutputStream using the specified character encoding.
 This method uses String(char[]) and String.getBytes(String). 
Params:
data – the char array to write, do not modify during output,
null ignored
output – the OutputStream to write to
encoding – the encoding to use, null means platform default
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
2.3/**
     * Writes chars from a <code>char[]</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding.
     * <p>
     * This method uses {@link String#String(char[])} and
     * {@link String#getBytes(String)}.
     *
     * @param data the char array to write, do not modify during output,
     * null ignored
     * @param output the <code>OutputStream</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.3
     */
    public static void write(final char[] data, final OutputStream output, final Charset encoding) throws IOException {
        if (data != null) {
            output.write(new String(data).getBytes(Charsets.toCharset(encoding)));
        }
    }

    
Writes chars from a char[] to bytes on an
OutputStream using the specified character encoding.

Character encoding names can be found at
IANA.
 This method uses String(char[]) and String.getBytes(String). 
Params:
data – the char array to write, do not modify during output,
null ignored
output – the OutputStream to write to
encoding – the encoding to use, null means platform default
Throws:
NullPointerException –                         if output is null
IOException –                                  if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Since:
1.1/**
     * Writes chars from a <code>char[]</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link String#String(char[])} and
     * {@link String#getBytes(String)}.
     *
     * @param data the char array to write, do not modify during output,
     * null ignored
     * @param output the <code>OutputStream</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException                         if output is null
     * @throws IOException                                  if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     * .UnsupportedEncodingException} in version 2.2 if the encoding is not supported.
     * @since 1.1
     */
    public static void write(final char[] data, final OutputStream output, final String encoding)
            throws IOException {
        write(data, output, Charsets.toCharset(encoding));
    }

    // write CharSequence
    //-----------------------------------------------------------------------

    
Writes chars from a CharSequence to a Writer.
Params:
data – the CharSequence to write, null ignored
output – the Writer to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
2.0/**
     * Writes chars from a <code>CharSequence</code> to a <code>Writer</code>.
     *
     * @param data the <code>CharSequence</code> to write, null ignored
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.0
     */
    public static void write(final CharSequence data, final Writer output) throws IOException {
        if (data != null) {
            write(data.toString(), output);
        }
    }

    
Writes chars from a CharSequence to bytes on an
OutputStream using the default character encoding of the
platform.
 This method uses String.getBytes(). 
Params:
data – the CharSequence to write, null ignored
output – the OutputStream to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
2.0
Deprecated:
2.5 use write(CharSequence, OutputStream, Charset) instead/**
     * Writes chars from a <code>CharSequence</code> to bytes on an
     * <code>OutputStream</code> using the default character encoding of the
     * platform.
     * <p>
     * This method uses {@link String#getBytes()}.
     *
     * @param data the <code>CharSequence</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.0
     * @deprecated 2.5 use {@link #write(CharSequence, OutputStream, Charset)} instead
     */
    @Deprecated
    public static void write(final CharSequence data, final OutputStream output)
            throws IOException {
        write(data, output, Charset.defaultCharset());
    }

    
Writes chars from a CharSequence to bytes on an
OutputStream using the specified character encoding.
 This method uses String.getBytes(String). 
Params:
data – the CharSequence to write, null ignored
output – the OutputStream to write to
encoding – the encoding to use, null means platform default
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
2.3/**
     * Writes chars from a <code>CharSequence</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding.
     * <p>
     * This method uses {@link String#getBytes(String)}.
     *
     * @param data the <code>CharSequence</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.3
     */
    public static void write(final CharSequence data, final OutputStream output, final Charset encoding)
            throws IOException {
        if (data != null) {
            write(data.toString(), output, encoding);
        }
    }

    
Writes chars from a CharSequence to bytes on an
OutputStream using the specified character encoding.

Character encoding names can be found at
IANA.
 This method uses String.getBytes(String). 
Params:
data – the CharSequence to write, null ignored
output – the OutputStream to write to
encoding – the encoding to use, null means platform default
Throws:
NullPointerException –        if output is null
IOException –                 if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Since:
2.0/**
     * Writes chars from a <code>CharSequence</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link String#getBytes(String)}.
     *
     * @param data the <code>CharSequence</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException        if output is null
     * @throws IOException                 if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     * .UnsupportedEncodingException} in version 2.2 if the encoding is not supported.
     * @since 2.0
     */
    public static void write(final CharSequence data, final OutputStream output, final String encoding)
            throws IOException {
        write(data, output, Charsets.toCharset(encoding));
    }

    // write String
    //-----------------------------------------------------------------------

    
Writes chars from a String to a Writer.
Params:
data – the String to write, null ignored
output – the Writer to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
1.1/**
     * Writes chars from a <code>String</code> to a <code>Writer</code>.
     *
     * @param data the <code>String</code> to write, null ignored
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     */
    public static void write(final String data, final Writer output) throws IOException {
        if (data != null) {
            output.write(data);
        }
    }

    
Writes chars from a String to bytes on an
OutputStream using the default character encoding of the
platform.
 This method uses String.getBytes(). 
Params:
data – the String to write, null ignored
output – the OutputStream to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
1.1
Deprecated:
2.5 use write(String, OutputStream, Charset) instead/**
     * Writes chars from a <code>String</code> to bytes on an
     * <code>OutputStream</code> using the default character encoding of the
     * platform.
     * <p>
     * This method uses {@link String#getBytes()}.
     *
     * @param data the <code>String</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     * @deprecated 2.5 use {@link #write(String, OutputStream, Charset)} instead
     */
    @Deprecated
    public static void write(final String data, final OutputStream output)
            throws IOException {
        write(data, output, Charset.defaultCharset());
    }

    
Writes chars from a String to bytes on an
OutputStream using the specified character encoding.
 This method uses String.getBytes(String). 
Params:
data – the String to write, null ignored
output – the OutputStream to write to
encoding – the encoding to use, null means platform default
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
2.3/**
     * Writes chars from a <code>String</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding.
     * <p>
     * This method uses {@link String#getBytes(String)}.
     *
     * @param data the <code>String</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.3
     */
    public static void write(final String data, final OutputStream output, final Charset encoding) throws IOException {
        if (data != null) {
            output.write(data.getBytes(Charsets.toCharset(encoding)));
        }
    }

    
Writes chars from a String to bytes on an
OutputStream using the specified character encoding.

Character encoding names can be found at
IANA.
 This method uses String.getBytes(String). 
Params:
data – the String to write, null ignored
output – the OutputStream to write to
encoding – the encoding to use, null means platform default
Throws:
NullPointerException –        if output is null
IOException –                 if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Since:
1.1/**
     * Writes chars from a <code>String</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link String#getBytes(String)}.
     *
     * @param data the <code>String</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException        if output is null
     * @throws IOException                 if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     * .UnsupportedEncodingException} in version 2.2 if the encoding is not supported.
     * @since 1.1
     */
    public static void write(final String data, final OutputStream output, final String encoding)
            throws IOException {
        write(data, output, Charsets.toCharset(encoding));
    }

    // write StringBuffer
    //-----------------------------------------------------------------------

    
Writes chars from a StringBuffer to a Writer.
Params:
data – the StringBuffer to write, null ignored
output – the Writer to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
1.1
Deprecated:
replaced by write(CharSequence, Writer)/**
     * Writes chars from a <code>StringBuffer</code> to a <code>Writer</code>.
     *
     * @param data the <code>StringBuffer</code> to write, null ignored
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     * @deprecated replaced by write(CharSequence, Writer)
     */
    @Deprecated
    public static void write(final StringBuffer data, final Writer output)
            throws IOException {
        if (data != null) {
            output.write(data.toString());
        }
    }

    
Writes chars from a StringBuffer to bytes on an
OutputStream using the default character encoding of the
platform.
 This method uses String.getBytes(). 
Params:
data – the StringBuffer to write, null ignored
output – the OutputStream to write to
Throws:
NullPointerException – if output is null
IOException –          if an I/O error occurs
Since:
1.1
Deprecated:
replaced by write(CharSequence, OutputStream)/**
     * Writes chars from a <code>StringBuffer</code> to bytes on an
     * <code>OutputStream</code> using the default character encoding of the
     * platform.
     * <p>
     * This method uses {@link String#getBytes()}.
     *
     * @param data the <code>StringBuffer</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     * @deprecated replaced by write(CharSequence, OutputStream)
     */
    @Deprecated
    public static void write(final StringBuffer data, final OutputStream output)
            throws IOException {
        write(data, output, (String) null);
    }

    
Writes chars from a StringBuffer to bytes on an
OutputStream using the specified character encoding.

Character encoding names can be found at
IANA.
 This method uses String.getBytes(String). 
Params:
data – the StringBuffer to write, null ignored
output – the OutputStream to write to
encoding – the encoding to use, null means platform default
Throws:
NullPointerException –        if output is null
IOException –                 if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Since:
1.1
Deprecated:
replaced by write(CharSequence, OutputStream, String)/**
     * Writes chars from a <code>StringBuffer</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link String#getBytes(String)}.
     *
     * @param data the <code>StringBuffer</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException        if output is null
     * @throws IOException                 if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     * .UnsupportedEncodingException} in version 2.2 if the encoding is not supported.
     * @since 1.1
     * @deprecated replaced by write(CharSequence, OutputStream, String)
     */
    @Deprecated
    public static void write(final StringBuffer data, final OutputStream output, final String encoding)
            throws IOException {
        if (data != null) {
            output.write(data.toString().getBytes(Charsets.toCharset(encoding)));
        }
    }

    // writeLines
    //-----------------------------------------------------------------------

    
Writes the toString() value of each item in a collection to
an OutputStream line by line, using the default character
encoding of the platform and the specified line ending.
Params:
lines – the lines to write, null entries produce blank lines
lineEnding – the line separator to use, null is system default
output – the OutputStream to write to, not null, not closed
Throws:
NullPointerException – if the output is null
IOException –          if an I/O error occurs
Since:
1.1
Deprecated:
2.5 use writeLines(Collection<?>, String, OutputStream, Charset) instead/**
     * Writes the <code>toString()</code> value of each item in a collection to
     * an <code>OutputStream</code> line by line, using the default character
     * encoding of the platform and the specified line ending.
     *
     * @param lines the lines to write, null entries produce blank lines
     * @param lineEnding the line separator to use, null is system default
     * @param output the <code>OutputStream</code> to write to, not null, not closed
     * @throws NullPointerException if the output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     * @deprecated 2.5 use {@link #writeLines(Collection, String, OutputStream, Charset)} instead
     */
    @Deprecated
    public static void writeLines(final Collection<?> lines, final String lineEnding,
                                  final OutputStream output) throws IOException {
        writeLines(lines, lineEnding, output, Charset.defaultCharset());
    }

    
Writes the toString() value of each item in a collection to
an OutputStream line by line, using the specified character
encoding and the specified line ending.
Params:
lines – the lines to write, null entries produce blank lines
lineEnding – the line separator to use, null is system default
output – the OutputStream to write to, not null, not closed
encoding – the encoding to use, null means platform default
Throws:
NullPointerException – if the output is null
IOException –          if an I/O error occurs
Since:
2.3/**
     * Writes the <code>toString()</code> value of each item in a collection to
     * an <code>OutputStream</code> line by line, using the specified character
     * encoding and the specified line ending.
     *
     * @param lines the lines to write, null entries produce blank lines
     * @param lineEnding the line separator to use, null is system default
     * @param output the <code>OutputStream</code> to write to, not null, not closed
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if the output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.3
     */
    public static void writeLines(final Collection<?> lines, String lineEnding, final OutputStream output,
                                  final Charset encoding) throws IOException {
        if (lines == null) {
            return;
        }
        if (lineEnding == null) {
            lineEnding = LINE_SEPARATOR;
        }
        final Charset cs = Charsets.toCharset(encoding);
        for (final Object line : lines) {
            if (line != null) {
                output.write(line.toString().getBytes(cs));
            }
            output.write(lineEnding.getBytes(cs));
        }
    }

    
Writes the toString() value of each item in a collection to
an OutputStream line by line, using the specified character
encoding and the specified line ending.

Character encoding names can be found at
IANA.
Params:
lines – the lines to write, null entries produce blank lines
lineEnding – the line separator to use, null is system default
output – the OutputStream to write to, not null, not closed
encoding – the encoding to use, null means platform default
Throws:
NullPointerException –                         if the output is null
IOException –                                  if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Since:
1.1/**
     * Writes the <code>toString()</code> value of each item in a collection to
     * an <code>OutputStream</code> line by line, using the specified character
     * encoding and the specified line ending.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     *
     * @param lines the lines to write, null entries produce blank lines
     * @param lineEnding the line separator to use, null is system default
     * @param output the <code>OutputStream</code> to write to, not null, not closed
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException                         if the output is null
     * @throws IOException                                  if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 1.1
     */
    public static void writeLines(final Collection<?> lines, final String lineEnding,
                                  final OutputStream output, final String encoding) throws IOException {
        writeLines(lines, lineEnding, output, Charsets.toCharset(encoding));
    }

    
Writes the toString() value of each item in a collection to
a Writer line by line, using the specified line ending.
Params:
lines – the lines to write, null entries produce blank lines
lineEnding – the line separator to use, null is system default
writer – the Writer to write to, not null, not closed
Throws:
NullPointerException – if the input is null
IOException –          if an I/O error occurs
Since:
1.1/**
     * Writes the <code>toString()</code> value of each item in a collection to
     * a <code>Writer</code> line by line, using the specified line ending.
     *
     * @param lines the lines to write, null entries produce blank lines
     * @param lineEnding the line separator to use, null is system default
     * @param writer the <code>Writer</code> to write to, not null, not closed
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     */
    public static void writeLines(final Collection<?> lines, String lineEnding,
                                  final Writer writer) throws IOException {
        if (lines == null) {
            return;
        }
        if (lineEnding == null) {
            lineEnding = LINE_SEPARATOR;
        }
        for (final Object line : lines) {
            if (line != null) {
                writer.write(line.toString());
            }
            writer.write(lineEnding);
        }
    }

    // copy from InputStream
    //-----------------------------------------------------------------------

    
Copies bytes from an InputStream to an
OutputStream.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.

Large streams (over 2GB) will return a bytes copied value of
-1 after the copy has completed since the correct
number of bytes cannot be returned as an int. For large streams
use the copyLarge(InputStream, OutputStream) method.
Params:
input – the InputStream to read from
output – the OutputStream to write to
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Returns:
the number of bytes copied, or -1 if > Integer.MAX_VALUE
Since:
1.1/**
     * Copies bytes from an <code>InputStream</code> to an
     * <code>OutputStream</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * Large streams (over 2GB) will return a bytes copied value of
     * <code>-1</code> after the copy has completed since the correct
     * number of bytes cannot be returned as an int. For large streams
     * use the <code>copyLarge(InputStream, OutputStream)</code> method.
     *
     * @param input the <code>InputStream</code> to read from
     * @param output the <code>OutputStream</code> to write to
     * @return the number of bytes copied, or -1 if &gt; Integer.MAX_VALUE
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     */
    public static int copy(final InputStream input, final OutputStream output) throws IOException {
        final long count = copyLarge(input, output);
        if (count > Integer.MAX_VALUE) {
            return -1;
        }
        return (int) count;
    }

    
Copies bytes from an InputStream to an OutputStream using an internal buffer of the
given size.

This method buffers the input internally, so there is no need to use a BufferedInputStream.

Params:
input – the InputStream to read from
output – the OutputStream to write to
bufferSize – the bufferSize used to copy from the input to the output
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Returns:
the number of bytes copied
Since:
2.5/**
     * Copies bytes from an <code>InputStream</code> to an <code>OutputStream</code> using an internal buffer of the
     * given size.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedInputStream</code>.
     * <p>
     *
     * @param input the <code>InputStream</code> to read from
     * @param output the <code>OutputStream</code> to write to
     * @param bufferSize the bufferSize used to copy from the input to the output
     * @return the number of bytes copied
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.5
     */
    public static long copy(final InputStream input, final OutputStream output, final int bufferSize)
            throws IOException {
        return copyLarge(input, output, new byte[bufferSize]);
    }

    
Copies bytes from a large (over 2GB) InputStream to an
OutputStream.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
 The buffer size is given by DEFAULT_BUFFER_SIZE. 
Params:
input – the InputStream to read from
output – the OutputStream to write to
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Returns:
the number of bytes copied
Since:
1.3/**
     * Copies bytes from a large (over 2GB) <code>InputStream</code> to an
     * <code>OutputStream</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
     *
     * @param input the <code>InputStream</code> to read from
     * @param output the <code>OutputStream</code> to write to
     * @return the number of bytes copied
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.3
     */
    public static long copyLarge(final InputStream input, final OutputStream output)
            throws IOException {
        return copy(input, output, DEFAULT_BUFFER_SIZE);
    }

    
Copies bytes from a large (over 2GB) InputStream to an
OutputStream.

This method uses the provided buffer, so there is no need to use a
BufferedInputStream.

Params:
input – the InputStream to read from
output – the OutputStream to write to
buffer – the buffer to use for the copy
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Returns:
the number of bytes copied
Since:
2.2/**
     * Copies bytes from a large (over 2GB) <code>InputStream</code> to an
     * <code>OutputStream</code>.
     * <p>
     * This method uses the provided buffer, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     *
     * @param input the <code>InputStream</code> to read from
     * @param output the <code>OutputStream</code> to write to
     * @param buffer the buffer to use for the copy
     * @return the number of bytes copied
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(final InputStream input, final OutputStream output, final byte[] buffer)
            throws IOException {
        long count = 0;
        int n;
        while (EOF != (n = input.read(buffer))) {
            output.write(buffer, 0, n);
            count += n;
        }
        return count;
    }

    
Copies some or all bytes from a large (over 2GB) InputStream to an
OutputStream, optionally skipping input bytes.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.

 Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped. 
 The buffer size is given by DEFAULT_BUFFER_SIZE. 
Params:
input – the InputStream to read from
output – the OutputStream to write to
inputOffset – : number of bytes to skip from input before copying
-ve values are ignored
length – : number of bytes to copy. -ve means all
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Returns:
the number of bytes copied
Since:
2.2/**
     * Copies some or all bytes from a large (over 2GB) <code>InputStream</code> to an
     * <code>OutputStream</code>, optionally skipping input bytes.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * </p>
     * <p>
     * Note that the implementation uses {@link #skip(InputStream, long)}.
     * This means that the method may be considerably less efficient than using the actual skip implementation,
     * this is done to guarantee that the correct number of characters are skipped.
     * </p>
     * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
     *
     * @param input the <code>InputStream</code> to read from
     * @param output the <code>OutputStream</code> to write to
     * @param inputOffset : number of bytes to skip from input before copying
     * -ve values are ignored
     * @param length : number of bytes to copy. -ve means all
     * @return the number of bytes copied
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(final InputStream input, final OutputStream output, final long inputOffset,
                                 final long length) throws IOException {
        return copyLarge(input, output, inputOffset, length, new byte[DEFAULT_BUFFER_SIZE]);
    }

    
Copies some or all bytes from a large (over 2GB) InputStream to an
OutputStream, optionally skipping input bytes.

This method uses the provided buffer, so there is no need to use a
BufferedInputStream.

 Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped. 
Params:
input – the InputStream to read from
output – the OutputStream to write to
inputOffset – : number of bytes to skip from input before copying
-ve values are ignored
length – : number of bytes to copy. -ve means all
buffer – the buffer to use for the copy
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Returns:
the number of bytes copied
Since:
2.2/**
     * Copies some or all bytes from a large (over 2GB) <code>InputStream</code> to an
     * <code>OutputStream</code>, optionally skipping input bytes.
     * <p>
     * This method uses the provided buffer, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * </p>
     * <p>
     * Note that the implementation uses {@link #skip(InputStream, long)}.
     * This means that the method may be considerably less efficient than using the actual skip implementation,
     * this is done to guarantee that the correct number of characters are skipped.
     * </p>
     *
     * @param input the <code>InputStream</code> to read from
     * @param output the <code>OutputStream</code> to write to
     * @param inputOffset : number of bytes to skip from input before copying
     * -ve values are ignored
     * @param length : number of bytes to copy. -ve means all
     * @param buffer the buffer to use for the copy
     * @return the number of bytes copied
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(final InputStream input, final OutputStream output,
                                 final long inputOffset, final long length, final byte[] buffer) throws IOException {
        if (inputOffset > 0) {
            skipFully(input, inputOffset);
        }
        if (length == 0) {
            return 0;
        }
        final int bufferLength = buffer.length;
        int bytesToRead = bufferLength;
        if (length > 0 && length < bufferLength) {
            bytesToRead = (int) length;
        }
        int read;
        long totalRead = 0;
        while (bytesToRead > 0 && EOF != (read = input.read(buffer, 0, bytesToRead))) {
            output.write(buffer, 0, read);
            totalRead += read;
            if (length > 0) { // only adjust length if not reading to the end
                // Note the cast must work because buffer.length is an integer
                bytesToRead = (int) Math.min(length - totalRead, bufferLength);
            }
        }
        return totalRead;
    }

    
Copies bytes from an InputStream to chars on a
Writer using the default character encoding of the platform.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
 This method uses InputStreamReader. 
Params:
input – the InputStream to read from
output – the Writer to write to
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Since:
1.1
Deprecated:
2.5 use copy(InputStream, Writer, Charset) instead/**
     * Copies bytes from an <code>InputStream</code> to chars on a
     * <code>Writer</code> using the default character encoding of the platform.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * This method uses {@link InputStreamReader}.
     *
     * @param input the <code>InputStream</code> to read from
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     * @deprecated 2.5 use {@link #copy(InputStream, Writer, Charset)} instead
     */
    @Deprecated
    public static void copy(final InputStream input, final Writer output)
            throws IOException {
        copy(input, output, Charset.defaultCharset());
    }

    
Copies bytes from an InputStream to chars on a
Writer using the specified character encoding.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.
 This method uses InputStreamReader. 
Params:
input – the InputStream to read from
output – the Writer to write to
inputEncoding – the encoding to use for the input stream, null means platform default
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Since:
2.3/**
     * Copies bytes from an <code>InputStream</code> to chars on a
     * <code>Writer</code> using the specified character encoding.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * This method uses {@link InputStreamReader}.
     *
     * @param input the <code>InputStream</code> to read from
     * @param output the <code>Writer</code> to write to
     * @param inputEncoding the encoding to use for the input stream, null means platform default
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.3
     */
    public static void copy(final InputStream input, final Writer output, final Charset inputEncoding)
            throws IOException {
        final InputStreamReader in = new InputStreamReader(input, Charsets.toCharset(inputEncoding));
        copy(in, output);
    }

    
Copies bytes from an InputStream to chars on a
Writer using the specified character encoding.

This method buffers the input internally, so there is no need to use a
BufferedInputStream.

Character encoding names can be found at
IANA.
 This method uses InputStreamReader. 
Params:
input – the InputStream to read from
output – the Writer to write to
inputEncoding – the encoding to use for the InputStream, null means platform default
Throws:
NullPointerException –                         if the input or output is null
IOException –                                  if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Since:
1.1/**
     * Copies bytes from an <code>InputStream</code> to chars on a
     * <code>Writer</code> using the specified character encoding.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link InputStreamReader}.
     *
     * @param input the <code>InputStream</code> to read from
     * @param output the <code>Writer</code> to write to
     * @param inputEncoding the encoding to use for the InputStream, null means platform default
     * @throws NullPointerException                         if the input or output is null
     * @throws IOException                                  if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 1.1
     */
    public static void copy(final InputStream input, final Writer output, final String inputEncoding)
            throws IOException {
        copy(input, output, Charsets.toCharset(inputEncoding));
    }

    // copy from Reader
    //-----------------------------------------------------------------------

    
Copies chars from a Reader to a Writer.

This method buffers the input internally, so there is no need to use a
BufferedReader.

Large streams (over 2GB) will return a chars copied value of
-1 after the copy has completed since the correct
number of chars cannot be returned as an int. For large streams
use the copyLarge(Reader, Writer) method.
Params:
input – the Reader to read from
output – the Writer to write to
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Returns:
the number of characters copied, or -1 if > Integer.MAX_VALUE
Since:
1.1/**
     * Copies chars from a <code>Reader</code> to a <code>Writer</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * Large streams (over 2GB) will return a chars copied value of
     * <code>-1</code> after the copy has completed since the correct
     * number of chars cannot be returned as an int. For large streams
     * use the <code>copyLarge(Reader, Writer)</code> method.
     *
     * @param input the <code>Reader</code> to read from
     * @param output the <code>Writer</code> to write to
     * @return the number of characters copied, or -1 if &gt; Integer.MAX_VALUE
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     */
    public static int copy(final Reader input, final Writer output) throws IOException {
        final long count = copyLarge(input, output);
        if (count > Integer.MAX_VALUE) {
            return -1;
        }
        return (int) count;
    }

    
Copies chars from a large (over 2GB) Reader to a Writer.

This method buffers the input internally, so there is no need to use a
BufferedReader.
 The buffer size is given by DEFAULT_BUFFER_SIZE. 
Params:
input – the Reader to read from
output – the Writer to write to
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Returns:
the number of characters copied
Since:
1.3/**
     * Copies chars from a large (over 2GB) <code>Reader</code> to a <code>Writer</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
     *
     * @param input the <code>Reader</code> to read from
     * @param output the <code>Writer</code> to write to
     * @return the number of characters copied
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.3
     */
    public static long copyLarge(final Reader input, final Writer output) throws IOException {
        return copyLarge(input, output, new char[DEFAULT_BUFFER_SIZE]);
    }

    
Copies chars from a large (over 2GB) Reader to a Writer.

This method uses the provided buffer, so there is no need to use a
BufferedReader.

Params:
input – the Reader to read from
output – the Writer to write to
buffer – the buffer to be used for the copy
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Returns:
the number of characters copied
Since:
2.2/**
     * Copies chars from a large (over 2GB) <code>Reader</code> to a <code>Writer</code>.
     * <p>
     * This method uses the provided buffer, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     *
     * @param input the <code>Reader</code> to read from
     * @param output the <code>Writer</code> to write to
     * @param buffer the buffer to be used for the copy
     * @return the number of characters copied
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(final Reader input, final Writer output, final char[] buffer) throws IOException {
        long count = 0;
        int n;
        while (EOF != (n = input.read(buffer))) {
            output.write(buffer, 0, n);
            count += n;
        }
        return count;
    }

    
Copies some or all chars from a large (over 2GB) InputStream to an
OutputStream, optionally skipping input chars.

This method buffers the input internally, so there is no need to use a
BufferedReader.
 The buffer size is given by DEFAULT_BUFFER_SIZE. 
Params:
input – the Reader to read from
output – the Writer to write to
inputOffset – : number of chars to skip from input before copying
-ve values are ignored
length – : number of chars to copy. -ve means all
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Returns:
the number of chars copied
Since:
2.2/**
     * Copies some or all chars from a large (over 2GB) <code>InputStream</code> to an
     * <code>OutputStream</code>, optionally skipping input chars.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
     *
     * @param input the <code>Reader</code> to read from
     * @param output the <code>Writer</code> to write to
     * @param inputOffset : number of chars to skip from input before copying
     * -ve values are ignored
     * @param length : number of chars to copy. -ve means all
     * @return the number of chars copied
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(final Reader input, final Writer output, final long inputOffset, final long length)
            throws IOException {
        return copyLarge(input, output, inputOffset, length, new char[DEFAULT_BUFFER_SIZE]);
    }

    
Copies some or all chars from a large (over 2GB) InputStream to an
OutputStream, optionally skipping input chars.

This method uses the provided buffer, so there is no need to use a
BufferedReader.

Params:
input – the Reader to read from
output – the Writer to write to
inputOffset – : number of chars to skip from input before copying
-ve values are ignored
length – : number of chars to copy. -ve means all
buffer – the buffer to be used for the copy
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Returns:
the number of chars copied
Since:
2.2/**
     * Copies some or all chars from a large (over 2GB) <code>InputStream</code> to an
     * <code>OutputStream</code>, optionally skipping input chars.
     * <p>
     * This method uses the provided buffer, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     *
     * @param input the <code>Reader</code> to read from
     * @param output the <code>Writer</code> to write to
     * @param inputOffset : number of chars to skip from input before copying
     * -ve values are ignored
     * @param length : number of chars to copy. -ve means all
     * @param buffer the buffer to be used for the copy
     * @return the number of chars copied
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(final Reader input, final Writer output, final long inputOffset, final long length,
                                 final char[] buffer)
            throws IOException {
        if (inputOffset > 0) {
            skipFully(input, inputOffset);
        }
        if (length == 0) {
            return 0;
        }
        int bytesToRead = buffer.length;
        if (length > 0 && length < buffer.length) {
            bytesToRead = (int) length;
        }
        int read;
        long totalRead = 0;
        while (bytesToRead > 0 && EOF != (read = input.read(buffer, 0, bytesToRead))) {
            output.write(buffer, 0, read);
            totalRead += read;
            if (length > 0) { // only adjust length if not reading to the end
                // Note the cast must work because buffer.length is an integer
                bytesToRead = (int) Math.min(length - totalRead, buffer.length);
            }
        }
        return totalRead;
    }

    
Copies chars from a Reader to bytes on an
OutputStream using the default character encoding of the
platform, and calling flush.

This method buffers the input internally, so there is no need to use a
BufferedReader.

Due to the implementation of OutputStreamWriter, this method performs a
flush.
 This method uses OutputStreamWriter. 
Params:
input – the Reader to read from
output – the OutputStream to write to
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Since:
1.1
Deprecated:
2.5 use copy(Reader, OutputStream, Charset) instead/**
     * Copies chars from a <code>Reader</code> to bytes on an
     * <code>OutputStream</code> using the default character encoding of the
     * platform, and calling flush.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * Due to the implementation of OutputStreamWriter, this method performs a
     * flush.
     * <p>
     * This method uses {@link OutputStreamWriter}.
     *
     * @param input the <code>Reader</code> to read from
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     * @deprecated 2.5 use {@link #copy(Reader, OutputStream, Charset)} instead
     */
    @Deprecated
    public static void copy(final Reader input, final OutputStream output)
            throws IOException {
        copy(input, output, Charset.defaultCharset());
    }

    
Copies chars from a Reader to bytes on an
OutputStream using the specified character encoding, and
calling flush.

This method buffers the input internally, so there is no need to use a
BufferedReader.


Due to the implementation of OutputStreamWriter, this method performs a
flush.

 This method uses OutputStreamWriter. 
Params:
input – the Reader to read from
output – the OutputStream to write to
outputEncoding – the encoding to use for the OutputStream, null means platform default
Throws:
NullPointerException – if the input or output is null
IOException –          if an I/O error occurs
Since:
2.3/**
     * Copies chars from a <code>Reader</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding, and
     * calling flush.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * </p>
     * <p>
     * Due to the implementation of OutputStreamWriter, this method performs a
     * flush.
     * </p>
     * <p>
     * This method uses {@link OutputStreamWriter}.
     * </p>
     *
     * @param input the <code>Reader</code> to read from
     * @param output the <code>OutputStream</code> to write to
     * @param outputEncoding the encoding to use for the OutputStream, null means platform default
     * @throws NullPointerException if the input or output is null
     * @throws IOException          if an I/O error occurs
     * @since 2.3
     */
    public static void copy(final Reader input, final OutputStream output, final Charset outputEncoding)
            throws IOException {
        final OutputStreamWriter out = new OutputStreamWriter(output, Charsets.toCharset(outputEncoding));
        copy(input, out);
        // XXX Unless anyone is planning on rewriting OutputStreamWriter,
        // we have to flush here.
        out.flush();
    }

    
Copies chars from a Reader to bytes on an
OutputStream using the specified character encoding, and
calling flush.

This method buffers the input internally, so there is no need to use a
BufferedReader.

Character encoding names can be found at
IANA.

Due to the implementation of OutputStreamWriter, this method performs a
flush.
 This method uses OutputStreamWriter. 
Params:
input – the Reader to read from
output – the OutputStream to write to
outputEncoding – the encoding to use for the OutputStream, null means platform default
Throws:
NullPointerException –                         if the input or output is null
IOException –                                  if an I/O error occurs
UnsupportedCharsetException – thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Since:
1.1/**
     * Copies chars from a <code>Reader</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding, and
     * calling flush.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * Character encoding names can be found at
     * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * Due to the implementation of OutputStreamWriter, this method performs a
     * flush.
     * <p>
     * This method uses {@link OutputStreamWriter}.
     *
     * @param input the <code>Reader</code> to read from
     * @param output the <code>OutputStream</code> to write to
     * @param outputEncoding the encoding to use for the OutputStream, null means platform default
     * @throws NullPointerException                         if the input or output is null
     * @throws IOException                                  if an I/O error occurs
     * @throws java.nio.charset.UnsupportedCharsetException thrown instead of {@link java.io
     *                                                      .UnsupportedEncodingException} in version 2.2 if the
     *                                                      encoding is not supported.
     * @since 1.1
     */
    public static void copy(final Reader input, final OutputStream output, final String outputEncoding)
            throws IOException {
        copy(input, output, Charsets.toCharset(outputEncoding));
    }

    // content equals
    //-----------------------------------------------------------------------

    
Compares the contents of two Streams to determine if they are equal or
not.

This method buffers the input internally using
BufferedInputStream if they are not already buffered.
Params:
input1 – the first stream
input2 – the second stream
Throws:
NullPointerException – if either input is null
IOException –          if an I/O error occurs
Returns:
true if the content of the streams are equal or they both don't
exist, false otherwise/**
     * Compares the contents of two Streams to determine if they are equal or
     * not.
     * <p>
     * This method buffers the input internally using
     * <code>BufferedInputStream</code> if they are not already buffered.
     *
     * @param input1 the first stream
     * @param input2 the second stream
     * @return true if the content of the streams are equal or they both don't
     * exist, false otherwise
     * @throws NullPointerException if either input is null
     * @throws IOException          if an I/O error occurs
     */
    public static boolean contentEquals(InputStream input1, InputStream input2)
            throws IOException {
        if (input1 == input2) {
            return true;
        }
        if (!(input1 instanceof BufferedInputStream)) {
            input1 = new BufferedInputStream(input1);
        }
        if (!(input2 instanceof BufferedInputStream)) {
            input2 = new BufferedInputStream(input2);
        }

        int ch = input1.read();
        while (EOF != ch) {
            final int ch2 = input2.read();
            if (ch != ch2) {
                return false;
            }
            ch = input1.read();
        }

        final int ch2 = input2.read();
        return ch2 == EOF;
    }

    
Compares the contents of two Readers to determine if they are equal or
not.

This method buffers the input internally using
BufferedReader if they are not already buffered.
Params:
input1 – the first reader
input2 – the second reader
Throws:
NullPointerException – if either input is null
IOException –          if an I/O error occurs
Returns:
true if the content of the readers are equal or they both don't
exist, false otherwise
Since:
1.1/**
     * Compares the contents of two Readers to determine if they are equal or
     * not.
     * <p>
     * This method buffers the input internally using
     * <code>BufferedReader</code> if they are not already buffered.
     *
     * @param input1 the first reader
     * @param input2 the second reader
     * @return true if the content of the readers are equal or they both don't
     * exist, false otherwise
     * @throws NullPointerException if either input is null
     * @throws IOException          if an I/O error occurs
     * @since 1.1
     */
    public static boolean contentEquals(Reader input1, Reader input2)
            throws IOException {
        if (input1 == input2) {
            return true;
        }

        input1 = toBufferedReader(input1);
        input2 = toBufferedReader(input2);

        int ch = input1.read();
        while (EOF != ch) {
            final int ch2 = input2.read();
            if (ch != ch2) {
                return false;
            }
            ch = input1.read();
        }

        final int ch2 = input2.read();
        return ch2 == EOF;
    }

    
Compares the contents of two Readers to determine if they are equal or
not, ignoring EOL characters.

This method buffers the input internally using
BufferedReader if they are not already buffered.
Params:
input1 – the first reader
input2 – the second reader
Throws:
NullPointerException – if either input is null
IOException –          if an I/O error occurs
Returns:
true if the content of the readers are equal (ignoring EOL differences),  false otherwise
Since:
2.2/**
     * Compares the contents of two Readers to determine if they are equal or
     * not, ignoring EOL characters.
     * <p>
     * This method buffers the input internally using
     * <code>BufferedReader</code> if they are not already buffered.
     *
     * @param input1 the first reader
     * @param input2 the second reader
     * @return true if the content of the readers are equal (ignoring EOL differences),  false otherwise
     * @throws NullPointerException if either input is null
     * @throws IOException          if an I/O error occurs
     * @since 2.2
     */
    public static boolean contentEqualsIgnoreEOL(final Reader input1, final Reader input2)
            throws IOException {
        if (input1 == input2) {
            return true;
        }
        final BufferedReader br1 = toBufferedReader(input1);
        final BufferedReader br2 = toBufferedReader(input2);

        String line1 = br1.readLine();
        String line2 = br2.readLine();
        while (line1 != null && line2 != null && line1.equals(line2)) {
            line1 = br1.readLine();
            line2 = br2.readLine();
        }
        return line1 == null ? line2 == null ? true : false : line1.equals(line2);
    }

    
Skips bytes from an input byte stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for skip() implementations in subclasses of InputStream. 
 Note that the implementation uses InputStream.read(byte[], int, int) rather than delegating to InputStream.skip(long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of bytes are skipped. 
Params:
input – byte stream to skip
toSkip – number of bytes to skip.
Throws:
IOException –              if there is a problem reading the file
IllegalArgumentException – if toSkip is negative
See Also:
InputStream.skip(long)
IO-203 - Add skipFully() method for InputStreams
Returns:
number of bytes actually skipped.
Since:
2.0/**
     * Skips bytes from an input byte stream.
     * This implementation guarantees that it will read as many bytes
     * as possible before giving up; this may not always be the case for
     * skip() implementations in subclasses of {@link InputStream}.
     * <p>
     * Note that the implementation uses {@link InputStream#read(byte[], int, int)} rather
     * than delegating to {@link InputStream#skip(long)}.
     * This means that the method may be considerably less efficient than using the actual skip implementation,
     * this is done to guarantee that the correct number of bytes are skipped.
     * </p>
     *
     * @param input byte stream to skip
     * @param toSkip number of bytes to skip.
     * @return number of bytes actually skipped.
     * @throws IOException              if there is a problem reading the file
     * @throws IllegalArgumentException if toSkip is negative
     * @see InputStream#skip(long)
     * @see <a href="https://issues.apache.org/jira/browse/IO-203">IO-203 - Add skipFully() method for InputStreams</a>
     * @since 2.0
     */
    public static long skip(final InputStream input, final long toSkip) throws IOException {
        if (toSkip < 0) {
            throw new IllegalArgumentException("Skip count must be non-negative, actual: " + toSkip);
        }
        /*
         * N.B. no need to synchronize this because: - we don't care if the buffer is created multiple times (the data
         * is ignored) - we always use the same size buffer, so if it it is recreated it will still be OK (if the buffer
         * size were variable, we would need to synch. to ensure some other thread did not create a smaller one)
         */
        if (SKIP_BYTE_BUFFER == null) {
            SKIP_BYTE_BUFFER = new byte[SKIP_BUFFER_SIZE];
        }
        long remain = toSkip;
        while (remain > 0) {
            // See https://issues.apache.org/jira/browse/IO-203 for why we use read() rather than delegating to skip()
            final long n = input.read(SKIP_BYTE_BUFFER, 0, (int) Math.min(remain, SKIP_BUFFER_SIZE));
            if (n < 0) { // EOF
                break;
            }
            remain -= n;
        }
        return toSkip - remain;
    }

    
Skips bytes from a ReadableByteChannel.
This implementation guarantees that it will read as many bytes
as possible before giving up.
Params:
input – ReadableByteChannel to skip
toSkip – number of bytes to skip.
Throws:
IOException –              if there is a problem reading the ReadableByteChannel
IllegalArgumentException – if toSkip is negative
Returns:
number of bytes actually skipped.
Since:
2.5/**
     * Skips bytes from a ReadableByteChannel.
     * This implementation guarantees that it will read as many bytes
     * as possible before giving up.
     *
     * @param input ReadableByteChannel to skip
     * @param toSkip number of bytes to skip.
     * @return number of bytes actually skipped.
     * @throws IOException              if there is a problem reading the ReadableByteChannel
     * @throws IllegalArgumentException if toSkip is negative
     * @since 2.5
     */
    public static long skip(final ReadableByteChannel input, final long toSkip) throws IOException {
        if (toSkip < 0) {
            throw new IllegalArgumentException("Skip count must be non-negative, actual: " + toSkip);
        }
        final ByteBuffer skipByteBuffer = ByteBuffer.allocate((int) Math.min(toSkip, SKIP_BUFFER_SIZE));
        long remain = toSkip;
        while (remain > 0) {
            skipByteBuffer.position(0);
            skipByteBuffer.limit((int) Math.min(remain, SKIP_BUFFER_SIZE));
            final int n = input.read(skipByteBuffer);
            if (n == EOF) {
                break;
            }
            remain -= n;
        }
        return toSkip - remain;
    }

    
Skips characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for skip() implementations in subclasses of Reader. 
 Note that the implementation uses Reader.read(char[], int, int) rather than delegating to Reader.skip(long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped. 
Params:
input – character stream to skip
toSkip – number of characters to skip.
Throws:
IOException –              if there is a problem reading the file
IllegalArgumentException – if toSkip is negative
See Also:
Reader.skip(long)
IO-203 - Add skipFully() method for InputStreams
Returns:
number of characters actually skipped.
Since:
2.0/**
     * Skips characters from an input character stream.
     * This implementation guarantees that it will read as many characters
     * as possible before giving up; this may not always be the case for
     * skip() implementations in subclasses of {@link Reader}.
     * <p>
     * Note that the implementation uses {@link Reader#read(char[], int, int)} rather
     * than delegating to {@link Reader#skip(long)}.
     * This means that the method may be considerably less efficient than using the actual skip implementation,
     * this is done to guarantee that the correct number of characters are skipped.
     * </p>
     *
     * @param input character stream to skip
     * @param toSkip number of characters to skip.
     * @return number of characters actually skipped.
     * @throws IOException              if there is a problem reading the file
     * @throws IllegalArgumentException if toSkip is negative
     * @see Reader#skip(long)
     * @see <a href="https://issues.apache.org/jira/browse/IO-203">IO-203 - Add skipFully() method for InputStreams</a>
     * @since 2.0
     */
    public static long skip(final Reader input, final long toSkip) throws IOException {
        if (toSkip < 0) {
            throw new IllegalArgumentException("Skip count must be non-negative, actual: " + toSkip);
        }
        /*
         * N.B. no need to synchronize this because: - we don't care if the buffer is created multiple times (the data
         * is ignored) - we always use the same size buffer, so if it it is recreated it will still be OK (if the buffer
         * size were variable, we would need to synch. to ensure some other thread did not create a smaller one)
         */
        if (SKIP_CHAR_BUFFER == null) {
            SKIP_CHAR_BUFFER = new char[SKIP_BUFFER_SIZE];
        }
        long remain = toSkip;
        while (remain > 0) {
            // See https://issues.apache.org/jira/browse/IO-203 for why we use read() rather than delegating to skip()
            final long n = input.read(SKIP_CHAR_BUFFER, 0, (int) Math.min(remain, SKIP_BUFFER_SIZE));
            if (n < 0) { // EOF
                break;
            }
            remain -= n;
        }
        return toSkip - remain;
    }

    
Skips the requested number of bytes or fail if there are not enough left.
 This allows for the possibility that InputStream.skip(long) may not skip as many bytes as requested (most likely because of reaching EOF). 
 Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped. 
Params:
input – stream to skip
toSkip – the number of bytes to skip
Throws:
IOException –              if there is a problem reading the file
IllegalArgumentException – if toSkip is negative
EOFException –             if the number of bytes skipped was incorrect
See Also:
InputStream.skip(long)
Since:
2.0/**
     * Skips the requested number of bytes or fail if there are not enough left.
     * <p>
     * This allows for the possibility that {@link InputStream#skip(long)} may
     * not skip as many bytes as requested (most likely because of reaching EOF).
     * <p>
     * Note that the implementation uses {@link #skip(InputStream, long)}.
     * This means that the method may be considerably less efficient than using the actual skip implementation,
     * this is done to guarantee that the correct number of characters are skipped.
     * </p>
     *
     * @param input stream to skip
     * @param toSkip the number of bytes to skip
     * @throws IOException              if there is a problem reading the file
     * @throws IllegalArgumentException if toSkip is negative
     * @throws EOFException             if the number of bytes skipped was incorrect
     * @see InputStream#skip(long)
     * @since 2.0
     */
    public static void skipFully(final InputStream input, final long toSkip) throws IOException {
        if (toSkip < 0) {
            throw new IllegalArgumentException("Bytes to skip must not be negative: " + toSkip);
        }
        final long skipped = skip(input, toSkip);
        if (skipped != toSkip) {
            throw new EOFException("Bytes to skip: " + toSkip + " actual: " + skipped);
        }
    }

    
Skips the requested number of bytes or fail if there are not enough left.
Params:
input – ReadableByteChannel to skip
toSkip – the number of bytes to skip
Throws:
IOException –              if there is a problem reading the ReadableByteChannel
IllegalArgumentException – if toSkip is negative
EOFException –             if the number of bytes skipped was incorrect
Since:
2.5/**
     * Skips the requested number of bytes or fail if there are not enough left.
     *
     * @param input ReadableByteChannel to skip
     * @param toSkip the number of bytes to skip
     * @throws IOException              if there is a problem reading the ReadableByteChannel
     * @throws IllegalArgumentException if toSkip is negative
     * @throws EOFException             if the number of bytes skipped was incorrect
     * @since 2.5
     */
    public static void skipFully(final ReadableByteChannel input, final long toSkip) throws IOException {
        if (toSkip < 0) {
            throw new IllegalArgumentException("Bytes to skip must not be negative: " + toSkip);
        }
        final long skipped = skip(input, toSkip);
        if (skipped != toSkip) {
            throw new EOFException("Bytes to skip: " + toSkip + " actual: " + skipped);
        }
    }

    
Skips the requested number of characters or fail if there are not enough left.
 This allows for the possibility that Reader.skip(long) may not skip as many characters as requested (most likely because of reaching EOF). 
 Note that the implementation uses skip(Reader, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped. 
Params:
input – stream to skip
toSkip – the number of characters to skip
Throws:
IOException –              if there is a problem reading the file
IllegalArgumentException – if toSkip is negative
EOFException –             if the number of characters skipped was incorrect
See Also:
Reader.skip(long)
Since:
2.0/**
     * Skips the requested number of characters or fail if there are not enough left.
     * <p>
     * This allows for the possibility that {@link Reader#skip(long)} may
     * not skip as many characters as requested (most likely because of reaching EOF).
     * <p>
     * Note that the implementation uses {@link #skip(Reader, long)}.
     * This means that the method may be considerably less efficient than using the actual skip implementation,
     * this is done to guarantee that the correct number of characters are skipped.
     * </p>
     *
     * @param input stream to skip
     * @param toSkip the number of characters to skip
     * @throws IOException              if there is a problem reading the file
     * @throws IllegalArgumentException if toSkip is negative
     * @throws EOFException             if the number of characters skipped was incorrect
     * @see Reader#skip(long)
     * @since 2.0
     */
    public static void skipFully(final Reader input, final long toSkip) throws IOException {
        final long skipped = skip(input, toSkip);
        if (skipped != toSkip) {
            throw new EOFException("Chars to skip: " + toSkip + " actual: " + skipped);
        }
    }


    
Reads characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for subclasses of Reader. 
Params:
input – where to read input from
buffer – destination
offset – initial offset into buffer
length – length to read, must be >= 0
Throws:
IOException – if a read error occurs
Returns:
actual length read; may be less than requested if EOF was reached
Since:
2.2/**
     * Reads characters from an input character stream.
     * This implementation guarantees that it will read as many characters
     * as possible before giving up; this may not always be the case for
     * subclasses of {@link Reader}.
     *
     * @param input where to read input from
     * @param buffer destination
     * @param offset initial offset into buffer
     * @param length length to read, must be &gt;= 0
     * @return actual length read; may be less than requested if EOF was reached
     * @throws IOException if a read error occurs
     * @since 2.2
     */
    public static int read(final Reader input, final char[] buffer, final int offset, final int length)
            throws IOException {
        if (length < 0) {
            throw new IllegalArgumentException("Length must not be negative: " + length);
        }
        int remaining = length;
        while (remaining > 0) {
            final int location = length - remaining;
            final int count = input.read(buffer, offset + location, remaining);
            if (EOF == count) { // EOF
                break;
            }
            remaining -= count;
        }
        return length - remaining;
    }

    
Reads characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for subclasses of Reader. 
Params:
input – where to read input from
buffer – destination
Throws:
IOException – if a read error occurs
Returns:
actual length read; may be less than requested if EOF was reached
Since:
2.2/**
     * Reads characters from an input character stream.
     * This implementation guarantees that it will read as many characters
     * as possible before giving up; this may not always be the case for
     * subclasses of {@link Reader}.
     *
     * @param input where to read input from
     * @param buffer destination
     * @return actual length read; may be less than requested if EOF was reached
     * @throws IOException if a read error occurs
     * @since 2.2
     */
    public static int read(final Reader input, final char[] buffer) throws IOException {
        return read(input, buffer, 0, buffer.length);
    }

    
Reads bytes from an input stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses of InputStream. 
Params:
input – where to read input from
buffer – destination
offset – initial offset into buffer
length – length to read, must be >= 0
Throws:
IOException – if a read error occurs
Returns:
actual length read; may be less than requested if EOF was reached
Since:
2.2/**
     * Reads bytes from an input stream.
     * This implementation guarantees that it will read as many bytes
     * as possible before giving up; this may not always be the case for
     * subclasses of {@link InputStream}.
     *
     * @param input where to read input from
     * @param buffer destination
     * @param offset initial offset into buffer
     * @param length length to read, must be &gt;= 0
     * @return actual length read; may be less than requested if EOF was reached
     * @throws IOException if a read error occurs
     * @since 2.2
     */
    public static int read(final InputStream input, final byte[] buffer, final int offset, final int length)
            throws IOException {
        if (length < 0) {
            throw new IllegalArgumentException("Length must not be negative: " + length);
        }
        int remaining = length;
        while (remaining > 0) {
            final int location = length - remaining;
            final int count = input.read(buffer, offset + location, remaining);
            if (EOF == count) { // EOF
                break;
            }
            remaining -= count;
        }
        return length - remaining;
    }

    
Reads bytes from an input stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses of InputStream. 
Params:
input – where to read input from
buffer – destination
Throws:
IOException – if a read error occurs
Returns:
actual length read; may be less than requested if EOF was reached
Since:
2.2/**
     * Reads bytes from an input stream.
     * This implementation guarantees that it will read as many bytes
     * as possible before giving up; this may not always be the case for
     * subclasses of {@link InputStream}.
     *
     * @param input where to read input from
     * @param buffer destination
     * @return actual length read; may be less than requested if EOF was reached
     * @throws IOException if a read error occurs
     * @since 2.2
     */
    public static int read(final InputStream input, final byte[] buffer) throws IOException {
        return read(input, buffer, 0, buffer.length);
    }

    
Reads bytes from a ReadableByteChannel.
 This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses of ReadableByteChannel. 
Params:
input – the byte channel to read
buffer – byte buffer destination
Throws:
IOException – if a read error occurs
Returns:
the actual length read; may be less than requested if EOF was reached
Since:
2.5/**
     * Reads bytes from a ReadableByteChannel.
     * <p>
     * This implementation guarantees that it will read as many bytes
     * as possible before giving up; this may not always be the case for
     * subclasses of {@link ReadableByteChannel}.
     *
     * @param input the byte channel to read
     * @param buffer byte buffer destination
     * @return the actual length read; may be less than requested if EOF was reached
     * @throws IOException if a read error occurs
     * @since 2.5
     */
    public static int read(final ReadableByteChannel input, final ByteBuffer buffer) throws IOException {
        final int length = buffer.remaining();
        while (buffer.remaining() > 0) {
            final int count = input.read(buffer);
            if (EOF == count) { // EOF
                break;
            }
        }
        return length - buffer.remaining();
    }

    
Reads the requested number of characters or fail if there are not enough left.
 This allows for the possibility that Reader.read(char[], int, int) may not read as many characters as requested (most likely because of reaching EOF). 
Params:
input – where to read input from
buffer – destination
offset – initial offset into buffer
length – length to read, must be >= 0
Throws:
IOException –              if there is a problem reading the file
IllegalArgumentException – if length is negative
EOFException –             if the number of characters read was incorrect
Since:
2.2/**
     * Reads the requested number of characters or fail if there are not enough left.
     * <p>
     * This allows for the possibility that {@link Reader#read(char[], int, int)} may
     * not read as many characters as requested (most likely because of reaching EOF).
     *
     * @param input where to read input from
     * @param buffer destination
     * @param offset initial offset into buffer
     * @param length length to read, must be &gt;= 0
     * @throws IOException              if there is a problem reading the file
     * @throws IllegalArgumentException if length is negative
     * @throws EOFException             if the number of characters read was incorrect
     * @since 2.2
     */
    public static void readFully(final Reader input, final char[] buffer, final int offset, final int length)
            throws IOException {
        final int actual = read(input, buffer, offset, length);
        if (actual != length) {
            throw new EOFException("Length to read: " + length + " actual: " + actual);
        }
    }

    
Reads the requested number of characters or fail if there are not enough left.
 This allows for the possibility that Reader.read(char[], int, int) may not read as many characters as requested (most likely because of reaching EOF). 
Params:
input – where to read input from
buffer – destination
Throws:
IOException –              if there is a problem reading the file
IllegalArgumentException – if length is negative
EOFException –             if the number of characters read was incorrect
Since:
2.2/**
     * Reads the requested number of characters or fail if there are not enough left.
     * <p>
     * This allows for the possibility that {@link Reader#read(char[], int, int)} may
     * not read as many characters as requested (most likely because of reaching EOF).
     *
     * @param input where to read input from
     * @param buffer destination
     * @throws IOException              if there is a problem reading the file
     * @throws IllegalArgumentException if length is negative
     * @throws EOFException             if the number of characters read was incorrect
     * @since 2.2
     */
    public static void readFully(final Reader input, final char[] buffer) throws IOException {
        readFully(input, buffer, 0, buffer.length);
    }

    
Reads the requested number of bytes or fail if there are not enough left.
 This allows for the possibility that InputStream.read(byte[], int, int) may not read as many bytes as requested (most likely because of reaching EOF). 
Params:
input – where to read input from
buffer – destination
offset – initial offset into buffer
length – length to read, must be >= 0
Throws:
IOException –              if there is a problem reading the file
IllegalArgumentException – if length is negative
EOFException –             if the number of bytes read was incorrect
Since:
2.2/**
     * Reads the requested number of bytes or fail if there are not enough left.
     * <p>
     * This allows for the possibility that {@link InputStream#read(byte[], int, int)} may
     * not read as many bytes as requested (most likely because of reaching EOF).
     *
     * @param input where to read input from
     * @param buffer destination
     * @param offset initial offset into buffer
     * @param length length to read, must be &gt;= 0
     * @throws IOException              if there is a problem reading the file
     * @throws IllegalArgumentException if length is negative
     * @throws EOFException             if the number of bytes read was incorrect
     * @since 2.2
     */
    public static void readFully(final InputStream input, final byte[] buffer, final int offset, final int length)
            throws IOException {
        final int actual = read(input, buffer, offset, length);
        if (actual != length) {
            throw new EOFException("Length to read: " + length + " actual: " + actual);
        }
    }

    
Reads the requested number of bytes or fail if there are not enough left.
 This allows for the possibility that InputStream.read(byte[], int, int) may not read as many bytes as requested (most likely because of reaching EOF). 
Params:
input – where to read input from
buffer – destination
Throws:
IOException –              if there is a problem reading the file
IllegalArgumentException – if length is negative
EOFException –             if the number of bytes read was incorrect
Since:
2.2/**
     * Reads the requested number of bytes or fail if there are not enough left.
     * <p>
     * This allows for the possibility that {@link InputStream#read(byte[], int, int)} may
     * not read as many bytes as requested (most likely because of reaching EOF).
     *
     * @param input where to read input from
     * @param buffer destination
     * @throws IOException              if there is a problem reading the file
     * @throws IllegalArgumentException if length is negative
     * @throws EOFException             if the number of bytes read was incorrect
     * @since 2.2
     */
    public static void readFully(final InputStream input, final byte[] buffer) throws IOException {
        readFully(input, buffer, 0, buffer.length);
    }

    
Reads the requested number of bytes or fail if there are not enough left.
 This allows for the possibility that InputStream.read(byte[], int, int) may not read as many bytes as requested (most likely because of reaching EOF). 
Params:
input – where to read input from
length – length to read, must be >= 0
Throws:
IOException –              if there is a problem reading the file
IllegalArgumentException – if length is negative
EOFException –             if the number of bytes read was incorrect
Returns:
the bytes read from input
Since:
2.5/**
     * Reads the requested number of bytes or fail if there are not enough left.
     * <p>
     * This allows for the possibility that {@link InputStream#read(byte[], int, int)} may
     * not read as many bytes as requested (most likely because of reaching EOF).
     *
     * @param input where to read input from
     * @param length length to read, must be &gt;= 0
     * @return the bytes read from input
     * @throws IOException              if there is a problem reading the file
     * @throws IllegalArgumentException if length is negative
     * @throws EOFException             if the number of bytes read was incorrect
     * @since 2.5
     */
    public static byte[] readFully(final InputStream input, final int length) throws IOException {
        final byte[] buffer = new byte[length];
        readFully(input, buffer, 0, buffer.length);
        return buffer;
    }

    
Reads the requested number of bytes or fail if there are not enough left.
 This allows for the possibility that ReadableByteChannel.read(ByteBuffer) may not read as many bytes as requested (most likely because of reaching EOF). 
Params:
input – the byte channel to read
buffer – byte buffer destination
Throws:
IOException –  if there is a problem reading the file
EOFException – if the number of bytes read was incorrect
Since:
2.5/**
     * Reads the requested number of bytes or fail if there are not enough left.
     * <p>
     * This allows for the possibility that {@link ReadableByteChannel#read(ByteBuffer)} may
     * not read as many bytes as requested (most likely because of reaching EOF).
     *
     * @param input the byte channel to read
     * @param buffer byte buffer destination
     * @throws IOException  if there is a problem reading the file
     * @throws EOFException if the number of bytes read was incorrect
     * @since 2.5
     */
    public static void readFully(final ReadableByteChannel input, final ByteBuffer buffer) throws IOException {
        final int expected = buffer.remaining();
        final int actual = read(input, buffer);
        if (actual != expected) {
            throw new EOFException("Length to read: " + expected + " actual: " + actual);
        }
    }

}