Netty Camel示例

Question

我对内蒂来说是个新手。

我在找一些样品。(最好使用Camel Netty组件和Spring，但不是必须的)

特别是一个使用TCP消息的示例Netty应用程序。

另外，我如何编写一个JUnit测试来测试这个网络应用程序呢？

谢谢，达尔

Answer 1

我假设您仍然希望与Camel集成。我首先看一下camel documentation。在这让你沮丧之后，你将需要开始尝试。我有一个例子，我创建了一个Camel处理器作为Netty服务器。Netty组件的工作方式是，From端点是消费的服务器，To端点是产生的客户端。我需要一个作为服务器的To端点，但组件不支持它。我简单地将Camel处理器实现为一个spring bean，它在Netty Server初始化时启动它。不过，JBoss Netty documentation and samples非常好。这是值得一步一步通过的。

下面是我的瘦身示例。它是一个向所有连接的客户端发送消息的服务器。如果您是Netty的新手，我强烈建议您查看上面链接的示例：

public class NettyServer implements Processor {

private final ChannelGroup channelGroup = new DefaultChannelGroup();
private NioServerSocketChannelFactory serverSocketChannelFactory = null;
private final ExecutorService executor = Executors.newCachedThreadPool();

private String listenAddress = "0.0.0.0"; // overridden by spring-osgi value
private int listenPort = 51501; // overridden by spring-osgi value

@Override
public void process(Exchange exchange) throws Exception {
    byte[] bytes = (byte[]) exchange.getIn().getBody();
    // send over the wire
    sendMessage(bytes);
}

public synchronized void sendMessage(byte[] message) {
    ChannelBuffer cb = ChannelBuffers.copiedBuffer(message);
    //writes to all clients connected.
    this.channelGroup.write(cb);
}

private class NettyServerHandler extends SimpleChannelUpstreamHandler {

    @Override
    public void channelOpen(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
        super.channelOpen(ctx, e);
        //add client to the group.
        NettyServer.this.channelGroup.add(e.getChannel());

    }

    // Perform an automatic recon.
    @Override
    public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
        super.channelConnected(ctx, e);
        // do something here when a clien connects.
    }

    @Override
    public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
        // Do something when a message is received...
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
        // Log the exception/
    }

}

private class PublishSocketServerPipelineFactory implements ChannelPipelineFactory {

    @Override
    public ChannelPipeline getPipeline() throws Exception {
        // need to set the handler.
        return Channels.pipeline(new NettyServerHandler());
    }
}

// called by spring to start the server
public void init() {

    try {
        this.serverSocketChannelFactory = new NioServerSocketChannelFactory(this.executor, this.executor);
        final ServerBootstrap serverBootstrap = new ServerBootstrap(this.serverSocketChannelFactory);
        serverBootstrap.setPipelineFactory(new PublishSocketServerPipelineFactory());
        serverBootstrap.setOption("reuseAddress", true);
        final InetSocketAddress listenSocketAddress = new InetSocketAddress(this.listenAddress, this.listenPort);
        this.channelGroup.add(serverBootstrap.bind(listenSocketAddress));

    } catch (Exception e) {

    }
}

// called by spring to shut down the server.
public void destroy() {

    try {
        this.channelGroup.close();
        this.serverSocketChannelFactory.releaseExternalResources();
        this.executor.shutdown();
    } catch (Exception e) {
    }
}

// injected by spring
public void setListenAddress(String listenAddress) {
    this.listenAddress = listenAddress;
}

// injected by spring
public void setListenPort(int listenPort) {
    this.listenPort = listenPort;
}

}

Answer 2

camel发行版有很多示例，但没有针对netty组件的简单示例。

Netty组件可以用来设置一个socket服务器来消费消息并向客户端返回响应。在网上搜索了一段时间后，我创建了自己的 tutorial using netty component in camel作为一个简单的Camel-Netty hello world示例来展示：

1. 使用camel中的netty组件接收TCP消息
2. 使用POJO类处理收到的消息并创建回客户端的response
3. Sending响应。