io.netty.handler.codec.compression

Class JZlibEncoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.handler.codec.MessageToByteEncoder<ByteBuf>

io.netty.handler.codec.compression.ZlibEncoder

io.netty.handler.codec.compression.JZlibEncoder

All Implemented Interfaces:

ChannelHandler

public class JZlibEncoder
extends ZlibEncoder

Compresses a ByteBuf using the deflate algorithm.

Nested Class Summary

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

ChannelHandler.Sharable, ChannelHandler.Skip

Constructor Summary

Constructors

Constructor and Description
JZlibEncoder() Creates a new zlib encoder with the default compression level (6), default window bits (15), default memory level (8), and the default wrapper (ZlibWrapper.ZLIB).
JZlibEncoder(byte[] dictionary) Creates a new zlib encoder with the default compression level (6), default window bits (15), default memory level (8), and the specified preset dictionary.
JZlibEncoder(int compressionLevel) Creates a new zlib encoder with the specified compressionLevel, default window bits (15), default memory level (8), and the default wrapper (ZlibWrapper.ZLIB).
JZlibEncoder(int compressionLevel, byte[] dictionary) Creates a new zlib encoder with the specified compressionLevel, default window bits (15), default memory level (8), and the specified preset dictionary.
JZlibEncoder(int compressionLevel, int windowBits, int memLevel, byte[] dictionary) Creates a new zlib encoder with the specified compressionLevel, the specified windowBits, the specified memLevel, and the specified preset dictionary.
JZlibEncoder(ZlibWrapper wrapper) Creates a new zlib encoder with the default compression level (6), default window bits (15), default memory level (8), and the specified wrapper.
JZlibEncoder(ZlibWrapper wrapper, int compressionLevel) Creates a new zlib encoder with the specified compressionLevel, default window bits (15), default memory level (8), and the specified wrapper.
JZlibEncoder(ZlibWrapper wrapper, int compressionLevel, int windowBits, int memLevel) Creates a new zlib encoder with the specified compressionLevel, the specified windowBits, the specified memLevel, and the specified wrapper.

Method Summary

Methods

Modifier and Type	Method and Description
ChannelFuture	close() Close this ZlibEncoder and so finish the encoding.
void	close(ChannelHandlerContext ctx, ChannelPromise promise) Calls ChannelHandlerContext.close(ChannelPromise) to forward to the next ChannelHandler in the ChannelPipeline.
ChannelFuture	close(ChannelPromise promise) Close this ZlibEncoder and so finish the encoding.
protected void	encode(ChannelHandlerContext ctx, ByteBuf in, ByteBuf out) Encode a message into a ByteBuf.
void	handlerAdded(ChannelHandlerContext ctx) Do nothing by default, sub-classes may override this method.
boolean	isClosed() Returns true if and only if the end of the compressed stream has been reached.

Methods inherited from class io.netty.handler.codec.MessageToByteEncoder

acceptOutboundMessage, allocateBuffer, write

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

bind, channelActive, channelInactive, channelRead, channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged, connect, deregister, disconnect, exceptionCaught, flush, handlerRemoved, isSharable, read, userEventTriggered

Methods inherited from class java.lang.Object

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

Constructor Detail

JZlibEncoder

public JZlibEncoder()

Creates a new zlib encoder with the default compression level (6), default window bits (15), default memory level (8), and the default wrapper (ZlibWrapper.ZLIB).

Throws:

CompressionException - if failed to initialize zlib

JZlibEncoder

public JZlibEncoder(int compressionLevel)

Creates a new zlib encoder with the specified compressionLevel, default window bits (15), default memory level (8), 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

JZlibEncoder

public JZlibEncoder(ZlibWrapper wrapper)

Creates a new zlib encoder with the default compression level (6), default window bits (15), default memory level (8), and the specified wrapper.

Throws:

CompressionException - if failed to initialize zlib

JZlibEncoder

public JZlibEncoder(ZlibWrapper wrapper,
            int compressionLevel)

Creates a new zlib encoder with the specified compressionLevel, default window bits (15), default memory level (8), 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

JZlibEncoder

public JZlibEncoder(ZlibWrapper wrapper,
            int compressionLevel,
            int windowBits,
            int memLevel)

Creates a new zlib encoder with the specified compressionLevel, the specified windowBits, the specified memLevel, 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.

windowBits - The base two logarithm of the size of the history buffer. The value should be in the range 9 to 15 inclusive. Larger values result in better compression at the expense of memory usage. The default value is 15.

memLevel - How much memory should be allocated for the internal compression state. 1 uses minimum memory and 9 uses maximum memory. Larger values result in better and faster compression at the expense of memory usage. The default value is 8

Throws:

CompressionException - if failed to initialize zlib

JZlibEncoder

public JZlibEncoder(byte[] dictionary)

Creates a new zlib encoder with the default compression level (6), default window bits (15), default memory level (8), 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

JZlibEncoder

public JZlibEncoder(int compressionLevel,
            byte[] dictionary)

Creates a new zlib encoder with the specified compressionLevel, default window bits (15), default memory level (8), 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

JZlibEncoder

public JZlibEncoder(int compressionLevel,
            int windowBits,
            int memLevel,
            byte[] dictionary)

Creates a new zlib encoder with the specified compressionLevel, the specified windowBits, the specified memLevel, 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.

windowBits - The base two logarithm of the size of the history buffer. The value should be in the range 9 to 15 inclusive. Larger values result in better compression at the expense of memory usage. The default value is 15.

memLevel - How much memory should be allocated for the internal compression state. 1 uses minimum memory and 9 uses maximum memory. Larger values result in better and faster compression at the expense of memory usage. The default value is 8

dictionary - the preset dictionary

Throws:

CompressionException - if failed to initialize zlib

Method Detail

close

public ChannelFuture close()

Description copied from class: ZlibEncoder

Close this ZlibEncoder and so finish the encoding. The returned ChannelFuture will be notified once the operation completes.

Specified by:

close in class ZlibEncoder

close

public ChannelFuture close(ChannelPromise promise)

Description copied from class: ZlibEncoder

Close this ZlibEncoder and so finish the encoding. The given ChannelFuture will be notified once the operation completes and will also be returned.

Specified by:

close in class ZlibEncoder

isClosed

public boolean isClosed()

Description copied from class: ZlibEncoder

Returns true if and only if the end of the compressed stream has been reached.

Specified by:

isClosed in class ZlibEncoder

encode

protected void encode(ChannelHandlerContext ctx,
          ByteBuf in,
          ByteBuf out)
               throws Exception

Description copied from class: MessageToByteEncoder

Encode a message into a ByteBuf. This method will be called for each written message that can be handled by this encoder.

Specified by:

encode in class MessageToByteEncoder<ByteBuf>

Parameters:

ctx - the ChannelHandlerContext which this MessageToByteEncoder belongs to

in - the message to encode

out - the ByteBuf into which the encoded message will be written

Throws:

Exception - is thrown if an error accour

close

public void close(ChannelHandlerContext ctx,
         ChannelPromise promise)

Description copied from class: ChannelHandlerAdapter

Calls ChannelHandlerContext.close(ChannelPromise) to forward to the next ChannelHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

close in interface ChannelHandler

Overrides:

close in class ChannelHandlerAdapter

Parameters:

ctx - the ChannelHandlerContext for which the close operation is made

promise - the ChannelPromise to notify once the operation completes

handlerAdded

public void handlerAdded(ChannelHandlerContext ctx)
                  throws Exception

Description copied from class: ChannelHandlerAdapter

Do nothing by default, sub-classes may override this method.

Specified by:

handlerAdded in interface ChannelHandler

Overrides:

handlerAdded in class ChannelHandlerAdapter

Throws:

Exception