io.netty.handler.codec

Class ByteToByteEncoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelOperationHandlerAdapter

io.netty.channel.ChannelOutboundByteHandlerAdapter

io.netty.handler.codec.ByteToByteEncoder

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelOperationHandler, io.netty.channel.ChannelOutboundByteHandler

Direct Known Subclasses:

SnappyFramedEncoder, ZlibEncoder

public abstract class ByteToByteEncoder
extends io.netty.channel.ChannelOutboundByteHandlerAdapter

ChannelOutboundByteHandlerAdapter which encodes bytes in a stream-like fashion from one ByteBuf to an other. This kind of decoder is often useful for doing on-the-fly processing like i.e. compression. But you can also do other things with it. For example here is an implementation which reads Integers from the input ByteBuf and square them before write them to the output ByteBuf.

     public class SquareEncoder extends ByteToByteEncoder {
         @Override
         public void encode(ChannelHandlerContext ctx, ByteBuf in, ByteBuf out)
                 throws Exception {
             if (in.readableBytes() < 4) {
                 return;
             }
             int value = in.readInt();
             out.writeInt(value * value);
         }
     }
 

Nested Class Summary

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

io.netty.channel.ChannelHandler.Sharable

Constructor Summary

Constructors

Constructor and Description
ByteToByteEncoder()

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract void	encode(io.netty.channel.ChannelHandlerContext ctx, io.netty.buffer.ByteBuf in, io.netty.buffer.ByteBuf out) Encodes the from one ByteBuf to an other.
protected void	flush(io.netty.channel.ChannelHandlerContext ctx, io.netty.buffer.ByteBuf in, io.netty.channel.ChannelPromise promise)

Methods inherited from class io.netty.channel.ChannelOutboundByteHandlerAdapter

discardOutboundReadBytes, flush, freeOutboundBuffer, newOutboundBuffer

Methods inherited from class io.netty.channel.ChannelOperationHandlerAdapter

bind, close, connect, deregister, disconnect, read, sendFile

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

afterAdd, afterRemove, beforeAdd, beforeRemove, exceptionCaught, userEventTriggered

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.ChannelOperationHandler

bind, close, connect, deregister, disconnect, read, sendFile

Methods inherited from interface io.netty.channel.ChannelHandler

afterAdd, afterRemove, beforeAdd, beforeRemove, exceptionCaught, userEventTriggered

Constructor Detail

ByteToByteEncoder

public ByteToByteEncoder()

Method Detail

flush

protected void flush(io.netty.channel.ChannelHandlerContext ctx,
         io.netty.buffer.ByteBuf in,
         io.netty.channel.ChannelPromise promise)
              throws Exception

Specified by:

flush in class io.netty.channel.ChannelOutboundByteHandlerAdapter

Throws:

Exception

encode

protected abstract void encode(io.netty.channel.ChannelHandlerContext ctx,
          io.netty.buffer.ByteBuf in,
          io.netty.buffer.ByteBuf out)
                        throws Exception

Encodes the from one ByteBuf to an other. This method will be called till either the input ByteBuf has nothing to read anymore or till nothing was read from the input ByteBuf.

Parameters:

ctx - the ChannelHandlerContext which this ByteToByteDecoder belongs to

in - the ByteBuf from which to read data

out - the ByteBuf to which the decoded data will be written

Throws:

Exception - is thrown if an error accour