org.jboss.netty.handler.codec.compression
Class ZlibEncoder

java.lang.Object
  org.jboss.netty.handler.codec.oneone.OneToOneEncoder
      org.jboss.netty.handler.codec.compression.ZlibEncoder

All Implemented Interfaces:

ChannelDownstreamHandler, ChannelHandler, LifeCycleAwareChannelHandler

public class ZlibEncoder
extends OneToOneEncoder
implements LifeCycleAwareChannelHandler

Compresses a ChannelBuffer using the deflate algorithm.

Version:

$Rev: 2241 $, $Date: 2010-04-16 13:12:43 +0900 (Fri, 16 Apr 2010) $

Author:

The Netty Project, Trustin Lee

Nested Class Summary

Nested classes/interfaces inherited from interface org.jboss.netty.channel.ChannelHandler

ChannelHandler.Sharable

Constructor Summary

ZlibEncoder()
Creates a new zlib encoder with the default compression level (6) and the default wrapper (ZlibWrapper.ZLIB).

ZlibEncoder(byte[] dictionary)
Creates a new zlib encoder with the default compression level (6) and the specified preset dictionary.

ZlibEncoder(int compressionLevel)
Creates a new zlib encoder with the specified compressionLevel and the default wrapper (ZlibWrapper.ZLIB).

ZlibEncoder(int compressionLevel, byte[] dictionary)
Creates a new zlib encoder with the specified compressionLevel and the specified preset dictionary.

ZlibEncoder(ZlibWrapper wrapper)
Creates a new zlib encoder with the default compression level (6) and the specified wrapper.

ZlibEncoder(ZlibWrapper wrapper, int compressionLevel)
Creates a new zlib encoder with the specified compressionLevel and the specified wrapper.

Method Summary

void	afterAdd(ChannelHandlerContext ctx)
void	afterRemove(ChannelHandlerContext ctx)
void	beforeAdd(ChannelHandlerContext ctx)
void	beforeRemove(ChannelHandlerContext ctx)
ChannelFuture	close()
protected Object	encode(ChannelHandlerContext ctx, Channel channel, Object msg) Transforms the specified message into another message and return the transformed message.
void	handleDownstream(ChannelHandlerContext ctx, ChannelEvent evt) Handles the specified downstream event.
boolean	isClosed()

Methods inherited from class java.lang.Object

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

Constructor Detail

ZlibEncoder

public ZlibEncoder()

Creates a new zlib encoder with the default compression level (6) and the default wrapper (ZlibWrapper.ZLIB).

Throws:

CompressionException - if failed to initialize zlib

ZlibEncoder

public ZlibEncoder(int compressionLevel)

Creates a new zlib encoder with the specified compressionLevel and the default wrapper (ZlibWrapper.ZLIB).

Parameters:

compressionLevel - 1 yields the fastest compression and 9 yields the best compression. 0 means no compression. The default compression level is 6.

Throws:

CompressionException - if failed to initialize zlib

ZlibEncoder

public ZlibEncoder(ZlibWrapper wrapper)

Creates a new zlib encoder with the default compression level (6) and the specified wrapper.

Throws:

CompressionException - if failed to initialize zlib

ZlibEncoder

public ZlibEncoder(ZlibWrapper wrapper,
                   int compressionLevel)

Creates a new zlib encoder with the specified compressionLevel and the specified wrapper.

Parameters:

compressionLevel - 1 yields the fastest compression and 9 yields the best compression. 0 means no compression. The default compression level is 6.

Throws:

CompressionException - if failed to initialize zlib

ZlibEncoder

public ZlibEncoder(byte[] dictionary)

Creates a new zlib encoder with the default compression level (6) and the specified preset dictionary. The wrapper is always ZlibWrapper.ZLIB because it is the only format that supports the preset dictionary.

Parameters:

dictionary - the preset dictionary

Throws:

CompressionException - if failed to initialize zlib

ZlibEncoder

public ZlibEncoder(int compressionLevel,
                   byte[] dictionary)

Creates a new zlib encoder with the specified compressionLevel and the specified preset dictionary. The wrapper is always ZlibWrapper.ZLIB because it is the only format that supports the preset dictionary.

Parameters:

compressionLevel - 1 yields the fastest compression and 9 yields the best compression. 0 means no compression. The default compression level is 6.

dictionary - the preset dictionary

Throws:

CompressionException - if failed to initialize zlib

Method Detail

close

public ChannelFuture close()

isClosed

public boolean isClosed()

encode

protected Object encode(ChannelHandlerContext ctx,
                        Channel channel,
                        Object msg)
                 throws Exception

Description copied from class: OneToOneEncoder

Transforms the specified message into another message and return the transformed message. Note that you can not return null, unlike you can in OneToOneDecoder.decode(ChannelHandlerContext, Channel, Object); you must return something, at least ChannelBuffers.EMPTY_BUFFER.

Specified by:

encode in class OneToOneEncoder

Throws:

Exception

handleDownstream

public void handleDownstream(ChannelHandlerContext ctx,
                             ChannelEvent evt)
                      throws Exception

Description copied from interface: ChannelDownstreamHandler

Handles the specified downstream event.

Specified by:

handleDownstream in interface ChannelDownstreamHandler

Overrides:

handleDownstream in class OneToOneEncoder

Parameters:

ctx - the context object for this handler

evt - the downstream event to process or intercept

Throws:

Exception

beforeAdd

public void beforeAdd(ChannelHandlerContext ctx)
               throws Exception

Specified by:

beforeAdd in interface LifeCycleAwareChannelHandler

Throws:

Exception

afterAdd

public void afterAdd(ChannelHandlerContext ctx)
              throws Exception

Specified by:

afterAdd in interface LifeCycleAwareChannelHandler

Throws:

Exception

beforeRemove

public void beforeRemove(ChannelHandlerContext ctx)
                  throws Exception

Specified by:

beforeRemove in interface LifeCycleAwareChannelHandler

Throws:

Exception

afterRemove

public void afterRemove(ChannelHandlerContext ctx)
                 throws Exception

Specified by:

afterRemove in interface LifeCycleAwareChannelHandler

Throws:

Exception