/*
* $Header: /home/cvs/jakarta-commons/httpclient/src/java/org/apache/commons/httpclient/ContentLengthInputStream.java,v 1.6 2003/01/28 04:40:20 jsdever Exp $
* $Revision: 1.6 $
* $Date: 2003/01/28 04:40:20 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* .
*
* [Additional notices, if required by prior licensing conditions]
*
*/
package org.apache.commons.httpclient;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* Cuts the wrapped InputStream off after a specified number of bytes.
*
* @author Ortwin Glück
* @author Eric Johnson
* @author Mike Bowler
* @since 2.0
*/
public class ContentLengthInputStream extends FilterInputStream {
/**
* The maximum number of bytes that can be read from the stream. Subsequent
* read operations will return -1.
*/
private int contentLength;
/** The current position */
private int pos = 0;
/** True if the stream is closed. */
private boolean closed = false;
/**
* Creates a new length limited stream
*
* @param in The stream to wrap
* @param contentLength The maximum number of bytes that can be read from
* the stream. Subsequent read operations will return -1.
*/
public ContentLengthInputStream(InputStream in, int contentLength) {
super(in);
this.contentLength = contentLength;
}
/**
*
Reads until the end of the known length of content.
*
*
Does not close the underlying socket input, but instead leaves it
* primed to parse the next response.
* @throws IOException If an IO problem occurs.
*/
public void close() throws IOException {
if (!closed) {
try {
ChunkedInputStream.exhaustInputStream(this);
} finally {
// close after above so that we don't throw an exception trying
// to read after closed!
closed = true;
}
}
}
/**
* Read the next byte from the stream
* @return The next byte or -1 if the end of stream has been reached.
* @throws IOException If an IO problem occurs
* @see java.io.InputStream#read()
*/
public int read() throws IOException {
if (closed) {
throw new IOException("Attempted read from closed stream.");
}
if (pos >= contentLength) {
return -1;
}
pos++;
return super.read();
}
/**
* Does standard {@link InputStream#read(byte[], int, int)} behavior, but
* also notifies the watcher when the contents have been consumed.
*
* @param b The byte array to fill.
* @param off Start filling at this position.
* @param len The number of bytes to attempt to read.
* @return The number of bytes read, or -1 if the end of content has been
* reached.
*
* @throws java.io.IOException Should an error occur on the wrapped stream.
*/
public int read (byte[] b, int off, int len) throws java.io.IOException {
if (closed) {
throw new IOException("Attempted read from closed stream.");
}
if (pos >= contentLength) {
return -1;
}
if (pos + len > contentLength) {
len = contentLength - pos;
}
int count = super.read(b, off, len);
pos += count;
return count;
}
/**
* Read more bytes from the stream.
* @param b The byte array to put the new data in.
* @return The number of bytes read into the buffer.
* @throws IOException If an IO problem occurs
* @see java.io.InputStream#read(byte[])
*/
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
}
