org.apache.click.extras.filter
Class CompressionResponseStream

java.lang.Object
  java.io.OutputStream
      javax.servlet.ServletOutputStream
          org.apache.click.extras.filter.CompressionResponseStream

All Implemented Interfaces:

Closeable, Flushable

public class CompressionResponseStream
extends ServletOutputStream

Provides an implementation of ServletOutputStream that works with the CompressionServletResponseWrapper implementation.

Note this Jakarta Tomcat examples Filter is packaged in Click Extras for convenience.

Field Summary

protected byte[]	buffer The buffer through which all of our output bytes are passed.
protected int	bufferCount The number of data bytes currently in the buffer.
protected boolean	closed Has this stream been closed?
protected int	compressionThreshold The threshold number which decides to compress or not.
protected OutputStream	gzipstream The underlying gzip output stream to which we should write data.
protected int	length The content length past which we will not write, or -1 if there is no defined content length.
protected OutputStream	output The underlying output stream, either gzipped or servlet, to which we should write data.
protected HttpServletRequest	request The request with which this servlet is associated.
protected HttpServletResponse	response The response with which this servlet output stream is associated.

Constructor Summary

CompressionResponseStream(HttpServletResponse response, HttpServletRequest request)
Construct a servlet output stream associated with the specified Response.

Method Summary

void	close() Close this output stream, causing any buffered data to be flushed.
boolean	closed() Has this response stream been closed?
void	flush() Flush any buffered data for this output stream, which also causes the response to be committed.
void	flushToGZip() Flush the buffer to the gzip stream.
protected void	initializeGzip() Initialize the GZip output stream.
protected void	setBuffer(int threshold) Set the compressionThreshold number and create buffer for this size.
protected boolean	setContentEncodingGZip() Set the "Content-Encoding" header of the response to "gzip", returning true if the header was set, false otherwise.
void	write(byte[] b) Write b.length bytes from the specified byte array to our output stream.
void	write(byte[] b, int off, int len) Write len bytes from the specified byte array, starting at the specified offset, to our output stream.
void	write(int b) Write the specified byte to our output stream.
void	writeToGZip(byte[] b, int off, int len) Writes array of bytes to the compressed output stream.

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

compressionThreshold

protected int compressionThreshold

The threshold number which decides to compress or not. Users can configure in web.xml to set it to fit their needs.

buffer

protected byte[] buffer

The buffer through which all of our output bytes are passed.

bufferCount

protected int bufferCount

The number of data bytes currently in the buffer.

gzipstream

protected OutputStream gzipstream

The underlying gzip output stream to which we should write data.

closed

protected boolean closed

Has this stream been closed?

length

protected int length

The content length past which we will not write, or -1 if there is no defined content length.

response

protected HttpServletResponse response

The response with which this servlet output stream is associated.

request

protected HttpServletRequest request

The request with which this servlet is associated.

output

protected OutputStream output

The underlying output stream, either gzipped or servlet, to which we should write data.

Constructor Detail

CompressionResponseStream

public CompressionResponseStream(HttpServletResponse response,
                                 HttpServletRequest request)
                          throws IOException

Construct a servlet output stream associated with the specified Response.

Parameters:

response - The associated response

request - The associated request

Throws:

IOException - if an IO error occurs reading the response stream

Method Detail

setBuffer

protected void setBuffer(int threshold)

Set the compressionThreshold number and create buffer for this size.

Parameters:

threshold - the compression threshold in bytes

close

public void close()
           throws IOException

Close this output stream, causing any buffered data to be flushed. Consecutive calls to this method will be ignored.

Specified by:

close in interface Closeable

Overrides:

close in class OutputStream

Throws:

IOException - if an error occurs closing the response

flush

public void flush()
           throws IOException

Flush any buffered data for this output stream, which also causes the response to be committed.

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException - if an error occurs flushing the gzip stream

flushToGZip

public void flushToGZip()
                 throws IOException

Flush the buffer to the gzip stream.

Throws:

IOException - if an error occurs flushing the buffer

write

public void write(int b)
           throws IOException

Write the specified byte to our output stream.

Specified by:

write in class OutputStream

Parameters:

b - The byte to be written

Throws:

IOException - if an input/output error occurs

write

public void write(byte[] b)
           throws IOException

Write b.length bytes from the specified byte array to our output stream.

Overrides:

write in class OutputStream

Parameters:

b - The byte array to be written

Throws:

IOException - if an input/output error occurs

write

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

Write len bytes from the specified byte array, starting at the specified offset, to our output stream.

Overrides:

write in class OutputStream

Parameters:

b - The byte array containing the bytes to be written

off - Zero-relative starting offset of the bytes to be written

len - The number of bytes to be written

Throws:

IOException - if an input/output error occurs

writeToGZip

public void writeToGZip(byte[] b,
                        int off,
                        int len)
                 throws IOException

Writes array of bytes to the compressed output stream. This method will block until all the bytes are written.

Parameters:

b - the data to be written

off - the start offset of the data

len - the length of the data

Throws:

IOException - If an I/O error has occurred.

closed

public boolean closed()

Has this response stream been closed?

Returns:

true if the response stream has been closed

initializeGzip

protected void initializeGzip()
                       throws IOException

Initialize the GZip output stream.

This method delegates to setContentEncodingGZip() to set the GZip response Content-Encoding header.

Throws:

IOException - If an I/O error has occurred

setContentEncodingGZip

protected boolean setContentEncodingGZip()

Set the "Content-Encoding" header of the response to "gzip", returning true if the header was set, false otherwise.

This method will return false when it is invoked from a server side include (<jsp:include>), since its not possible to alter the headers of an included response.

Returns:

true if the content encoding was set, false otherwise