https://tomcat.apache.org/: javax.servlet package
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* 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 javax.servlet;
import java.io.IOException;
import java.io.InputStream;
Provides an input stream for reading binary data from a client request,
including an efficient readLine method for reading data one line
at a time. With some protocols, such as HTTP POST and PUT, a
ServletInputStream object can be used to read data sent from the
client.
A ServletInputStream object is normally retrieved via the ServletRequest.getInputStream method.
This is an abstract class that a servlet container implements. Subclasses of
this class must implement the java.io.InputStream.read() method.
See Also:
/**
* Provides an input stream for reading binary data from a client request,
* including an efficient <code>readLine</code> method for reading data one line
* at a time. With some protocols, such as HTTP POST and PUT, a
* <code>ServletInputStream</code> object can be used to read data sent from the
* client.
* <p>
* A <code>ServletInputStream</code> object is normally retrieved via the
* {@link ServletRequest#getInputStream} method.
* <p>
* This is an abstract class that a servlet container implements. Subclasses of
* this class must implement the <code>java.io.InputStream.read()</code> method.
*
* @see ServletRequest
*/
public abstract class ServletInputStream extends InputStream {
Does nothing, because this is an abstract class.
/**
* Does nothing, because this is an abstract class.
*/
protected ServletInputStream() {
// NOOP
}
Reads the input stream, one line at a time. Starting at an offset, reads
bytes into an array, until it reads a certain number of bytes or reaches
a newline character, which it reads into the array as well.
This method returns -1 if it reaches the end of the input stream before
reading the maximum number of bytes.
Params: - b –
an array of bytes into which data is read
- off –
an integer specifying the character at which this method
begins reading
- len –
an integer specifying the maximum number of bytes to read
Throws: - IOException –
if an input or output exception has occurred
Returns: an integer specifying the actual number of bytes read, or -1 if
the end of the stream is reached
/**
* Reads the input stream, one line at a time. Starting at an offset, reads
* bytes into an array, until it reads a certain number of bytes or reaches
* a newline character, which it reads into the array as well.
* <p>
* This method returns -1 if it reaches the end of the input stream before
* reading the maximum number of bytes.
*
* @param b
* an array of bytes into which data is read
* @param off
* an integer specifying the character at which this method
* begins reading
* @param len
* an integer specifying the maximum number of bytes to read
* @return an integer specifying the actual number of bytes read, or -1 if
* the end of the stream is reached
* @exception IOException
* if an input or output exception has occurred
*/
public int readLine(byte[] b, int off, int len) throws IOException {
if (len <= 0) {
return 0;
}
int count = 0, c;
while ((c = read()) != -1) {
b[off++] = (byte) c;
count++;
if (c == '\n' || count == len) {
break;
}
}
return count > 0 ? count : -1;
}
Has the end of this InputStream been reached?
Returns: true if all the data has been read from the stream,
else falseSince: Servlet 3.1
/**
* Has the end of this InputStream been reached?
*
* @return <code>true</code> if all the data has been read from the stream,
* else <code>false</code>
*
* @since Servlet 3.1
*/
public abstract boolean isFinished();
Can data be read from this InputStream without blocking? Returns If this method is called and returns false, the container will invoke ReadListener.onDataAvailable() when data is available. Returns: true if data can be read without blocking, else
falseSince: Servlet 3.1
/**
* Can data be read from this InputStream without blocking?
* Returns If this method is called and returns false, the container will
* invoke {@link ReadListener#onDataAvailable()} when data is available.
*
* @return <code>true</code> if data can be read without blocking, else
* <code>false</code>
*
* @since Servlet 3.1
*/
public abstract boolean isReady();
Sets the ReadListener for this ServletInputStream and thereby switches to non-blocking IO. It is only valid to switch to non-blocking IO within async processing or HTTP upgrade processing. Params: - listener – The non-blocking IO read listener
Throws: - IllegalStateException – If this method is called if neither async nor HTTP upgrade is in progress or if the
ReadListener has already been set - NullPointerException – If listener is null
Since: Servlet 3.1
/**
* Sets the {@link ReadListener} for this {@link ServletInputStream} and
* thereby switches to non-blocking IO. It is only valid to switch to
* non-blocking IO within async processing or HTTP upgrade processing.
*
* @param listener The non-blocking IO read listener
*
* @throws IllegalStateException If this method is called if neither
* async nor HTTP upgrade is in progress or
* if the {@link ReadListener} has already
* been set
* @throws NullPointerException If listener is null
*
* @since Servlet 3.1
*/
public abstract void setReadListener(ReadListener listener);
}