How to route calls to another system

[crunc...@gmail.com]

Looking at Netty in Action and some SO posts, I saw that in order to talk to another system, you can use Bootstrap() to create a new client and attach it to the current eventLoop.  Looking at the proxy example, it's done when the initial server is bootstrapped as well.  So I tried

public void start(final ApplicationContext applicationContext) throws Exception {

        NioEventLoopGroup bossGroup = new NioEventLoopGroup(1);

        NioEventLoopGroup workerGroup = new NioEventLoopGroup();

        try {

            bootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)

                    .handler(new LoggingHandler(LogLevel.INFO)).childHandler(new ChannelInitializer<SocketChannel>() {

                        @Override

                        protected void initChannel(SocketChannel ch) throws Exception {

                            ch.pipeline().addLast(new ServerHandlerImpl());
                            ch.pipeline().addLast(new SomeOtherHandler());

                        }

                        @Override

                        protected void channelActive(ChannelHandlerContext ctx) throws Exception {

                            Bootstrap clientBootstrap = new Bootstrap();

                            clientBootstrap.channel(NioSocketChannel.class)

                                    .handler(new ChannelInitializer<SocketChannel>() {

                                        @Override

                                        protected void initChannel(SocketChannel ch) throws Exception {

                                            ch.pipeline().addLast(new CredentialsClientHandler());

                                        }

                                    });

                            clientBootstrap.group(ctx.channel().eventLoop());

                            ChannelFuture future = clientBootstrap.connect(host, port);

                        }

                    });

So when a message comes in and it reaches the ServerHandlerImpl, I want it to then route its message to CredentialsClientHandler that would send a message to another server, check the credentials, and then resume the rest of the pipeline.  In ServerHandlerImpl, how do I "send a message" down the other handler and not down SomeOtherHandler?  

[Zhu Ran]

1.don't create new client bootstrap in the channelActive, create a client bootstrap at the application level, as same as the server bootstrap;

2.add the SomeOtherHandler to the client bootstrap pipeline;

3.after the client bootstrap connected to the remote server, save the ChannelHandlerContext in somewhere such as a global object;

4.when you want to send something to the remote server, use the ChannelHandlerContext you save in the global object