org.ibisph.filter.gzip
Class ResponseStream

java.lang.Object
  java.io.OutputStream
      javax.servlet.ServletOutputStream
          org.ibisph.filter.gzip.ResponseStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable

public class ResponseStream
extends javax.servlet.ServletOutputStream

Provides gzip stream compression for the gzip filter and response wrapper.

Author:

Garth Braithwaite, STG

Field Summary

protected javax.servlet.ServletOutputStream	destinationOutputStream
protected java.util.zip.GZIPOutputStream	gzipOutputStream

Constructor Summary

ResponseStream(javax.servlet.http.HttpServletResponse response)
Constructor which saves original destination response and creates a new gzip output stream.

Method Summary

void	close() Core method that causes the captured content to be zipped and streamed back.
void	flush() Flushes the captured gzipped output stream but does not close.
void	write(byte b) Overridden method that captures data to the buffered byte array which is then gzipped.
void	write(byte[] b) Overridden method that captures data to the buffered byte array which is then gzipped.
void	write(byte[] b, int off, int len) Overridden method that captures data to the buffered byte array which is then gzipped.
void	write(int b) Overridden method that captures data to the buffered byte array which is then gzipped.

Methods inherited from class javax.servlet.ServletOutputStream

print, print, print, print, print, print, print, println, println, println, println, println, println, println, println

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

destinationOutputStream

protected javax.servlet.ServletOutputStream destinationOutputStream

gzipOutputStream

protected java.util.zip.GZIPOutputStream gzipOutputStream

Constructor Detail

ResponseStream

public ResponseStream(javax.servlet.http.HttpServletResponse response)
               throws java.io.IOException

Constructor which saves original destination response and creates a new gzip output stream. Saves the original response's output stream to be used as the compressions output stream. Creates a new gzipped output stream which will feed data via this objects write methods. The saved/ original response will have the "Content-Encoding" header with a value of "gzip" added.

Parameters:

response - Original response object which contains the "real" destination output stream.

Throws:

java.io.IOException

Method Detail

write

public void write(byte b)
           throws java.io.IOException

Overridden method that captures data to the buffered byte array which is then gzipped.

Parameters:

b - Value to be written to the output stream.

Throws:

java.io.IOException - standard IOException associated with write operation.

write

public void write(int b)
           throws java.io.IOException

Overridden method that captures data to the buffered byte array which is then gzipped.

Specified by:

write in class java.io.OutputStream

Parameters:

b - Value to be written to the output stream.

Throws:

java.io.IOException

write

public void write(byte[] b)
           throws java.io.IOException

Overridden method that captures data to the buffered byte array which is then gzipped.

Overrides:

write in class java.io.OutputStream

Parameters:

b - Array of values to be written to the output stream.

Throws:

java.io.IOException

write

public void write(byte[] b,
                  int off,
                  int len)
           throws java.io.IOException

Overridden method that captures data to the buffered byte array which is then gzipped.

Overrides:

write in class java.io.OutputStream

Parameters:

b - Array of values to be written to the output stream.

off - Offset of where to write the bytes to the new captured output stream.

len - Number of bytes to the new captured output stream.

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Core method that causes the captured content to be zipped and streamed back. Finishes the captured gzipped output stream (actually causes the gzip object to process the data), it then flushes the "real" destination output stream and closes it.

Specified by:

close in interface java.io.Closeable

Overrides:

close in class java.io.OutputStream

Throws:

java.io.IOException

flush

public void flush()
           throws java.io.IOException

Flushes the captured gzipped output stream but does not close.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.OutputStream

Throws:

java.io.IOException