| NonBlockingBufferedInputStream.java |
/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 2001-2003 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 acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Axis" 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 name, without prior written
* permission of the Apache Software Foundation.
*
* 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
* <http://www.apache.org/>.
*/
package org.jboss.axis.transport.http;
import java.io.IOException;
import java.io.InputStream;
public class NonBlockingBufferedInputStream extends InputStream
{
// current stream to be processed
private InputStream in;
// maximum number of bytes allowed to be returned.
private int remainingContent = Integer.MAX_VALUE;
// Internal buffer for the input stream
private byte[] buffer = new byte[4096];
private int offset = 0; // bytes before this offset have been processed
private int numbytes = 0; // number of valid bytes in this buffer
/**
* set the input stream to be used for subsequent reads
*
* @param in the InputStream
*/
public void setInputStream(InputStream in)
{
this.in = in;
numbytes = 0;
offset = 0;
remainingContent = (in == null) ? 0 : Integer.MAX_VALUE;
}
/**
* set the maximum number of bytes allowed to be read from this input
* stream.
*
* @param value the Content Length
*/
public void setContentLength(int value)
{
if (in != null) this.remainingContent = value - (numbytes - offset);
}
/**
* Replenish the buffer with data from the input stream. This is
* guaranteed to read atleast one byte or throw an exception. When
* possible, it will read up to the length of the buffer
* the data is buffered for efficiency.
*
* @return the byte read
*/
private void refillBuffer() throws IOException
{
if (remainingContent <= 0 || in == null) return;
// determine number of bytes to read
numbytes = in.available();
if (numbytes > remainingContent) numbytes = remainingContent;
if (numbytes > buffer.length) numbytes = buffer.length;
if (numbytes <= 0) numbytes = 1;
// actually attempt to read those bytes
numbytes = in.read(buffer, 0, numbytes);
// update internal state to reflect this read
remainingContent -= numbytes;
offset = 0;
}
/**
* Read a byte from the input stream, blocking if necessary. Internally
* the data is buffered for efficiency.
*
* @return the byte read
*/
public int read() throws IOException
{
if (in == null) return -1;
if (offset >= numbytes) refillBuffer();
if (offset >= numbytes) return -1;
return buffer[offset++];
}
/**
* Read bytes from the input stream. This is guaranteed to return at
* least one byte or throw an exception. When possible, it will return
* more bytes, up to the length of the array, as long as doing so would
* not require waiting on bytes from the input stream.
*
* @param dest byte array to read into
* @return the number of bytes actually read
*/
public int read(byte[] dest) throws IOException
{
return read(dest, 0, dest.length);
}
/**
* Read a specified number of bytes from the input stream. This is
* guaranteed to return at least one byte or throw an execption. When
* possible, it will return more bytes, up to the length specified,
* as long as doing so would not require waiting on bytes from the
* input stream.
*
* @param dest byte array to read into
* @param off starting offset into the byte array
* @param len maximum number of bytes to read
* @return the number of bytes actually read
*/
public int read(byte[] dest, int off, int len) throws IOException
{
int ready = numbytes - offset;
if (ready >= len)
{
System.arraycopy(buffer, offset, dest, off, len);
offset += len;
return len;
}
else if (ready > 0)
{
System.arraycopy(buffer, offset, dest, off, ready);
offset = numbytes;
return ready;
}
else
{
if (in == null) return -1;
refillBuffer();
if (offset >= numbytes) return -1;
return read(dest, off, len);
}
}
/**
* skip over (and discard) a specified number of bytes in this input
* stream
*
* @param len the number of bytes to be skipped
* @return the action number of bytes skipped
*/
public int skip(int len) throws IOException
{
int count = 0;
while (len-- > 0 && read() >= 0) count++;
return count;
}
/**
* return the number of bytes available to be read without blocking
*
* @return the number of bytes
*/
public int available() throws IOException
{
if (in == null) return 0;
// return buffered + available from the stream
return (numbytes - offset) + in.available();
}
/**
* disassociate from the underlying input stream
*/
public void close() throws IOException
{
setInputStream(null);
}
/**
* Just like read except byte is not removed from the buffer.
* the data is buffered for efficiency.
* Was added to support multiline http headers. ;-)
*
* @return the byte read
*/
public int peek() throws IOException
{
if (in == null) return -1;
if (offset >= numbytes) refillBuffer();
if (offset >= numbytes) return -1;
return buffer[offset];
}
}
| NonBlockingBufferedInputStream.java |