用Spring集成框架实现Tcp连接

Question

我试图创建一个接受入站连接的Tcp服务器，并异步地向连接的客户端发送消息。有一个Tcp服务器的示例，但它使用的是网关，是请求/响应，不支持异步。

null

@EnableIntegration
@IntegrationComponentScan
@Configuration
public class IntegrationConfig implements
        ApplicationListener<TcpConnectionEvent> {
    @Value("${listen.port:8000}")
    private int port;

    @Bean  //for accepting text message from TCP, putty
    public MessageChannel fromTcp() {
        return new DirectChannel();
    }

    @Bean  //for sending text message to TCP client, outbound
    public MessageChannel toTcp() {
        return new DirectChannel();
    }

    // receive from MVC controller
    @Bean
    public MessageChannel invokeChannel() {
        return new DirectChannel();
    }   

    @Bean  //inbound, it is working, I could read the inbound message while debugging
    public TcpReceivingChannelAdapter in(
            AbstractServerConnectionFactory connectionFactory) {
        TcpReceivingChannelAdapter adapter = new TcpReceivingChannelAdapter();
        adapter.setOutputChannel(fromTcp());
        adapter.setConnectionFactory(connectionFactory);
        return adapter;
    }

    //transform TCP bytes to string message, working
    @Transformer(inputChannel = "fromTcp", outputChannel = "toCollaborate")
    public String convert(byte[] bytes) {

        return new String(bytes);
    }

    MessageHeaders staticheader;  //save ip_connectinId, use this to collaborate outbound message later, for testing purpose only
    @ServiceActivator(inputChannel = "toCollaborate", outputChannel = "toTcp")
    public Message<String> handleTcpMessage(Message<String> stringMsg) {
        staticheader = stringMsg.getHeaders();
        return stringMsg;
        // save the header, collaborate to output channel
    }

    //collaborate message from REST API invokeChannel to a outbound tcp client, this fail
    @Transformer(inputChannel = "invokeChannel", outputChannel = "toTcp")
    public Message<String> headerBeforeSend(String test) {
        GenericMessage<String> msg = new GenericMessage<String>(
                "from rest api");
        if (staticheader != null) {         
            MessageBuilder
                    .fromMessage(msg)
                    .setHeader("ip_connectionId",
                            staticheader.get("ip_connectionId")).build();
        }
        return msg;
    }

    @ServiceActivator(inputChannel = "toTcp")
    @Bean
    public TcpSendingMessageHandler out(
            AbstractServerConnectionFactory connectionFactory) {
        TcpSendingMessageHandler tcpOutboundAdp = new TcpSendingMessageHandler();
        tcpOutboundAdp.setConnectionFactory(connectionFactory);


        return tcpOutboundAdp;
    }   

    // should need only 1 factory? and keep connectin alive
    // server for in coming connection
    @Bean
    public AbstractServerConnectionFactory serverCF() {
        return new TcpNetServerConnectionFactory(this.port);
    }

    @Override
    public void onApplicationEvent(TcpConnectionEvent tcpEvent) {
        // TODO Auto-generated method stub
        TcpConnection source = (TcpConnection) tcpEvent.getSource();

    }

}
//The MVC controller
@Autowired
    MessageChannel invokeChannel;
    @RequestMapping(value="/invoke")
    public String sayHello()
    {
        //trigger gateway to send a message
        String msg = "hello";
        MessagingTemplate template = new MessagingTemplate();
        template.send(invokeChannel, new GenericMessage<String>(msg));      
        return msg;
    }

异常org.springframework.web.util.NestedServletException：请求处理失败；嵌套异常是org.springframework.messaging.messagehandlingException：无法找到出站套接字org.springframework.web.servlet.frameworkservlet.processRequest（frameworkservlet.java:981)org.springframework.web.servlet.frameworkservlet.doget（(wsfilter.java:52)

Answer 1

是；默认情况下，连接保持打开；是的，您可以使用@serviceactivator来处理请求；是的，您只需设置连接id标头。

要在Java配置中配置出站适配器，请将@serviceactivator添加到处理程序bean...

@Bean
public TcpReceivingChannelAdapter() in() {

    ...
    adapter.setOutputChannel(newRequests());

}


...

@ServiceActivator(inputChannel="toClientChannel")
@Bean
public TcpSendingMessageHandler out() {

    ...

}