JdkZlibEncoder (Netty API Reference (4.0.56.Final))

java.lang.Object
- io.netty.channel.ChannelHandlerAdapter
- - io.netty.channel.ChannelOutboundHandlerAdapter
  - - io.netty.handler.codec.MessageToByteEncoder<ByteBuf>
    - - io.netty.handler.codec.compression.ZlibEncoder
      - io.netty.handler.codec.compression.JdkZlibEncoder

All Implemented Interfaces:

ChannelHandler, ChannelOutboundHandler
```
public class JdkZlibEncoder
extends ZlibEncoder
```
Compresses a ByteBuf using the deflate algorithm.

Nested Class Summary
- Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler
  ChannelHandler.Sharable

Constructor Summary

Constructors
Constructor and Description
`JdkZlibEncoder()` Creates a new zlib encoder with the default compression level (`6`) and the default wrapper (`ZlibWrapper.ZLIB`).
`JdkZlibEncoder(byte[] dictionary)` Creates a new zlib encoder with the default compression level (`6`) and the specified preset dictionary.
`JdkZlibEncoder(int compressionLevel)` Creates a new zlib encoder with the specified `compressionLevel` and the default wrapper (`ZlibWrapper.ZLIB`).
`JdkZlibEncoder(int compressionLevel, byte[] dictionary)` Creates a new zlib encoder with the specified `compressionLevel` and the specified preset dictionary.
`JdkZlibEncoder(ZlibWrapper wrapper)` Creates a new zlib encoder with the default compression level (`6`) and the specified wrapper.
`JdkZlibEncoder(ZlibWrapper wrapper, int compressionLevel)` Creates a new zlib encoder with the specified `compressionLevel` and the specified wrapper.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected ByteBuf`	`allocateBuffer(ChannelHandlerContext ctx, ByteBuf msg, boolean preferDirect)` Allocate a `ByteBuf` which will be used as argument of `#encode(ChannelHandlerContext, I, ByteBuf)`.
`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 `ChannelOutboundHandler` in the `ChannelPipeline`.
`ChannelFuture`	`close(ChannelPromise promise)` Close this `ZlibEncoder` and so finish the encoding.
`protected void`	`encode(ChannelHandlerContext ctx, ByteBuf uncompressed, 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, write

Methods inherited from class io.netty.channel.ChannelOutboundHandlerAdapter
bind, connect, deregister, disconnect, flush, read

Methods inherited from class io.netty.channel.ChannelHandlerAdapter
ensureNotSharable, exceptionCaught, handlerRemoved, isSharable

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.netty.channel.ChannelHandler
exceptionCaught, handlerRemoved

- Constructor Detail
  - JdkZlibEncoder
```
public JdkZlibEncoder()
```
    Creates a new zlib encoder with the default compression level (6) and the default wrapper (ZlibWrapper.ZLIB).
    
    Throws:
    
    CompressionException - if failed to initialize zlib
  - JdkZlibEncoder
```
public JdkZlibEncoder(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
  - JdkZlibEncoder
```
public JdkZlibEncoder(ZlibWrapper wrapper)
```
    Creates a new zlib encoder with the default compression level (6) and the specified wrapper.
    
    Throws:
    
    CompressionException - if failed to initialize zlib
  - JdkZlibEncoder
```
public JdkZlibEncoder(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
  - JdkZlibEncoder
```
public JdkZlibEncoder(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
  - JdkZlibEncoder
```
public JdkZlibEncoder(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()
```
    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 uncompressed,
                      ByteBuf out)
               throws java.lang.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
    
    uncompressed - the message to encode
    
    out - the ByteBuf into which the encoded message will be written
    
    Throws:
    
    java.lang.Exception - is thrown if an error occurs
  - allocateBuffer
```
protected final ByteBuf allocateBuffer(ChannelHandlerContext ctx,
                                       ByteBuf msg,
                                       boolean preferDirect)
                                throws java.lang.Exception
```
    Description copied from class: MessageToByteEncoder
    
    Allocate a ByteBuf which will be used as argument of #encode(ChannelHandlerContext, I, ByteBuf). Sub-classes may override this method to return ByteBuf with a perfect matching initialCapacity.
    
    Overrides:
    
    allocateBuffer in class MessageToByteEncoder<ByteBuf>
    
    Throws:
    
    java.lang.Exception
  - close
```
public void close(ChannelHandlerContext ctx,
                  ChannelPromise promise)
           throws java.lang.Exception
```
    Description copied from class: ChannelOutboundHandlerAdapter
    
    Calls ChannelHandlerContext.close(ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.
    
    Specified by:
    
    close in interface ChannelOutboundHandler
    
    Overrides:
    
    close in class ChannelOutboundHandlerAdapter
    
    Parameters:
    
    ctx - the ChannelHandlerContext for which the close operation is made
    
    promise - the ChannelPromise to notify once the operation completes
    
    Throws:
    
    java.lang.Exception - thrown if an error occurs
  - handlerAdded
```
public void handlerAdded(ChannelHandlerContext ctx)
                  throws java.lang.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:
    
    java.lang.Exception

Class JdkZlibEncoder

Nested Class Summary

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

Constructor Summary

Method Summary

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

Methods inherited from class io.netty.channel.ChannelOutboundHandlerAdapter

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

Methods inherited from class java.lang.Object

Methods inherited from interface io.netty.channel.ChannelHandler

Constructor Detail

JdkZlibEncoder

JdkZlibEncoder

JdkZlibEncoder

JdkZlibEncoder

JdkZlibEncoder

JdkZlibEncoder

Method Detail

close

close

isClosed

encode

allocateBuffer

close

handlerAdded