org.jboss.netty.handler.codec.protobuf
Class ProtobufEncoder

java.lang.Object
  org.jboss.netty.handler.codec.oneone.OneToOneEncoder
      org.jboss.netty.handler.codec.protobuf.ProtobufEncoder

All Implemented Interfaces:

ChannelDownstreamHandler, ChannelHandler

@ChannelHandler.Sharable
public class ProtobufEncoder
extends OneToOneEncoder

Encodes the requested Google Protocol Buffers Message and MessageLite into a ChannelBuffer. A typical setup for TCP/IP would be:

 ChannelPipeline pipeline = ...;

 // Decoders
 pipeline.addLast("frameDecoder",
                  new LengthFieldBasedFrameDecoder(1048576, 0, 4, 0, 4));
 pipeline.addLast("protobufDecoder",
                  new ProtobufDecoder(MyMessage.getDefaultInstance()));

 // Encoder
 pipeline.addLast("frameEncoder", new LengthFieldPrepender(4));
 pipeline.addLast("protobufEncoder", new ProtobufEncoder());
 

and then you can use a MyMessage instead of a ChannelBuffer as a message:

 void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
     MyMessage req = (MyMessage) e.getMessage();
     MyMessage res = MyMessage.newBuilder().setText(
                               "Did you say '" + req.getText() + "'?").build();
     ch.write(res);
 }
 

Version:

$Rev:231 $, $Date:2008-06-12 16:44:50 +0900 (목, 12 6월 2008) $

Author:

The Netty Project, Trustin Lee

Nested Class Summary

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

ChannelHandler.Sharable

Constructor Summary

ProtobufEncoder()
Creates a new instance.

Method Summary

protected Object

encode(ChannelHandlerContext ctx, Channel channel, Object msg) Transforms the specified message into another message and return the transformed message.

Methods inherited from class org.jboss.netty.handler.codec.oneone.OneToOneEncoder

handleDownstream

Methods inherited from class java.lang.Object

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

Constructor Detail

ProtobufEncoder

public ProtobufEncoder()

Creates a new instance.

Method Detail

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