io.netty.handler.codec

Class MessageToMessageDecoder<I>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelStateHandlerAdapter

io.netty.channel.ChannelInboundMessageHandlerAdapter<I>

io.netty.handler.codec.MessageToMessageDecoder<I>

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelHandlerUtil.SingleInboundMessageHandler<I>, io.netty.channel.ChannelInboundMessageHandler<I>, io.netty.channel.ChannelStateHandler

Direct Known Subclasses:

Base64Decoder, ByteArrayDecoder, ProtobufDecoder, StringDecoder

public abstract class MessageToMessageDecoder<I>
extends io.netty.channel.ChannelInboundMessageHandlerAdapter<I>

ChannelInboundMessageHandler which decodes from one message to an other message For example here is an implementation which decodes a String to an Integer which represent the length of the String.

     public class StringToIntegerDecoder extends
             MessageToMessageDecoder<String> {
         public StringToIntegerDecoder() {
             super(String.class);
         }

         @Override
         public Object decode(ChannelHandlerContext ctx, String message)
                 throws Exception {
             return message.length());
         }
     }
 

Nested Class Summary

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

io.netty.channel.ChannelHandler.Sharable

Field Summary

Fields inherited from class io.netty.channel.ChannelInboundMessageHandlerAdapter

ABORT

Constructor Summary

Constructors

Constructor and Description
MessageToMessageDecoder()

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract Object	decode(io.netty.channel.ChannelHandlerContext ctx, I msg) Decode from one message to an other.
void	messageReceived(io.netty.channel.ChannelHandlerContext ctx, I msg)

Methods inherited from class io.netty.channel.ChannelInboundMessageHandlerAdapter

acceptInboundMessage, beginMessageReceived, endMessageReceived, freeInboundBuffer, inboundBufferUpdated, newInboundBuffer

Methods inherited from class io.netty.channel.ChannelStateHandlerAdapter

channelActive, channelInactive, channelReadSuspended, channelRegistered, channelUnregistered, userEventTriggered

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

afterAdd, afterRemove, beforeAdd, beforeRemove, exceptionCaught

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.ChannelStateHandler

channelActive, channelInactive, channelReadSuspended, channelRegistered, channelUnregistered, userEventTriggered

Methods inherited from interface io.netty.channel.ChannelHandler

afterAdd, afterRemove, beforeAdd, beforeRemove, exceptionCaught

Constructor Detail

MessageToMessageDecoder

public MessageToMessageDecoder()

Method Detail

messageReceived

public final void messageReceived(io.netty.channel.ChannelHandlerContext ctx,
                   I msg)
                           throws Exception

Throws:

Exception

decode

protected abstract Object decode(io.netty.channel.ChannelHandlerContext ctx,
            I msg)
                          throws Exception

Decode from one message to an other. This method will be called till either the MessageBuf has nothing left or till this method returns null.

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageDecoder belongs to

msg - the message to decode to an other one

Returns:

message the decoded message or null if more messages are needed be cause the implementation needs to do some kind of aggragation

Throws:

Exception - is thrown if an error accour