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);
 }
 

Nested Class Summary

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

ChannelHandler.Sharable

Constructor Summary

Constructors

Constructor and Description
ProtobufEncoder()

Method Summary

Methods

Modifier and Type	Method and Description
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

doEncode, handleDownstream

Methods inherited from class java.lang.Object

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

Constructor Detail

ProtobufEncoder

public ProtobufEncoder()

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