/*
* 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
*
* https://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.tools.ant.filters;
import java.io.FilterReader;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.util.FileUtils;
Base class for core filter readers.
/**
* Base class for core filter readers.
*
*/
public abstract class BaseFilterReader extends FilterReader {
Buffer size used when reading /** Buffer size used when reading */
private static final int BUFFER_SIZE = 8192;
Have the parameters passed been interpreted? /** Have the parameters passed been interpreted? */
private boolean initialized = false;
The Ant project this filter is part of. /** The Ant project this filter is part of. */
private Project project = null;
Constructor used by Ant's introspection mechanism.
The original filter reader is only used for chaining
purposes, never for filtering purposes (and indeed
it would be useless for filtering purposes, as it has
no real data to filter). ChainedReaderHelper uses
this placeholder instance to create a chain of real filters.
/**
* Constructor used by Ant's introspection mechanism.
* The original filter reader is only used for chaining
* purposes, never for filtering purposes (and indeed
* it would be useless for filtering purposes, as it has
* no real data to filter). ChainedReaderHelper uses
* this placeholder instance to create a chain of real filters.
*/
public BaseFilterReader() {
super(new StringReader(""));
FileUtils.close(this);
}
Creates a new filtered reader.
Params: - in – A Reader object providing the underlying stream.
Must not be
null.
/**
* Creates a new filtered reader.
*
* @param in A Reader object providing the underlying stream.
* Must not be <code>null</code>.
*
*/
public BaseFilterReader(final Reader in) {
super(in);
}
Reads characters into a portion of an array. This method will block
until some input is available, an I/O error occurs, or the end of the
stream is reached.
Params: - cbuf – Destination buffer to write characters to.
Must not be
null. - off – Offset at which to start storing characters.
- len – Maximum number of characters to read.
Throws: - IOException – If an I/O error occurs
Returns: the number of characters read, or -1 if the end of the
stream has been reached
/**
* Reads characters into a portion of an array. This method will block
* until some input is available, an I/O error occurs, or the end of the
* stream is reached.
*
* @param cbuf Destination buffer to write characters to.
* Must not be <code>null</code>.
* @param off Offset at which to start storing characters.
* @param len Maximum number of characters to read.
*
* @return the number of characters read, or -1 if the end of the
* stream has been reached
*
* @exception IOException If an I/O error occurs
*/
public final int read(final char[] cbuf, final int off,
final int len) throws IOException {
for (int i = 0; i < len; i++) {
final int ch = read();
if (ch == -1) {
if (i == 0) {
return -1;
} else {
return i;
}
}
cbuf[off + i] = (char) ch;
}
return len;
}
Skips characters. This method will block until some characters are
available, an I/O error occurs, or the end of the stream is reached.
Params: - n – The number of characters to skip
Throws: - IllegalArgumentException – If
n is negative. - IOException – If an I/O error occurs
Returns: the number of characters actually skipped
/**
* Skips characters. This method will block until some characters are
* available, an I/O error occurs, or the end of the stream is reached.
*
* @param n The number of characters to skip
*
* @return the number of characters actually skipped
*
* @exception IllegalArgumentException If <code>n</code> is negative.
* @exception IOException If an I/O error occurs
*/
public final long skip(final long n)
throws IOException, IllegalArgumentException {
if (n < 0L) {
throw new IllegalArgumentException("skip value is negative");
}
for (long i = 0; i < n; i++) {
if (read() == -1) {
return i;
}
}
return n;
}
Sets the initialized status.
Params: - initialized – Whether or not the filter is initialized.
/**
* Sets the initialized status.
*
* @param initialized Whether or not the filter is initialized.
*/
protected final void setInitialized(final boolean initialized) {
this.initialized = initialized;
}
Returns the initialized status.
Returns: whether or not the filter is initialized
/**
* Returns the initialized status.
*
* @return whether or not the filter is initialized
*/
protected final boolean getInitialized() {
return initialized;
}
Sets the project to work with.
Params: - project – The project this filter is part of.
Should not be
null.
/**
* Sets the project to work with.
*
* @param project The project this filter is part of.
* Should not be <code>null</code>.
*/
public final void setProject(final Project project) {
this.project = project;
}
Returns the project this filter is part of.
Returns: the project this filter is part of
/**
* Returns the project this filter is part of.
*
* @return the project this filter is part of
*/
protected final Project getProject() {
return project;
}
Reads a line of text ending with '\n' (or until the end of the stream).
The returned String retains the '\n'.
Throws: - IOException – if the underlying reader throws one during
reading
Returns: the line read, or null if the end of the stream
has already been reached
/**
* Reads a line of text ending with '\n' (or until the end of the stream).
* The returned String retains the '\n'.
*
* @return the line read, or <code>null</code> if the end of the stream
* has already been reached
*
* @exception IOException if the underlying reader throws one during
* reading
*/
protected final String readLine() throws IOException {
int ch = in.read();
if (ch == -1) {
return null;
}
StringBuffer line = new StringBuffer();
while (ch != -1) {
line.append((char) ch);
if (ch == '\n') {
break;
}
ch = in.read();
}
return line.toString();
}
Reads to the end of the stream, returning the contents as a String.
Throws: - IOException – if the underlying reader throws one during
reading
Returns: the remaining contents of the reader, as a String
/**
* Reads to the end of the stream, returning the contents as a String.
*
* @return the remaining contents of the reader, as a String
*
* @exception IOException if the underlying reader throws one during
* reading
*/
protected final String readFully() throws IOException {
return FileUtils.readFully(in, BUFFER_SIZE);
}
}