如何使用 Spring Integration 动态创建多个 TcpOutboundGateways？

Question

我有一个场景，我需要一个客户端应用程序才能在应用程序启动时动态创建与可变数量的唯一主机/端口组合的 TCP 连接。我正在尝试使用 Spring Integration TcpOutboundGateway 来完成此操作，但一直无法找到解决方案。我希望每个主机/端口组合都有自己专用的 TcpOutboundGateway。到目前为止，我对 TcpOutboundGateway 的研究使我找到了以下单一网关解决方案……

@MessageGateway(defaultRequestChannel=“sendMessage”)
public interface myMessageGateway {
    byte[] sendMessage(String message);
}

@Bean
@ServiceActivator(inputChannel=“sendMessage”)
public MessageHandler tcpOutboundGateway(AbstractClientConnectionFactory factory) {
    TcpOutboundGateway gateway = new TcpOutboundGateway();
    gateway.setConnectionFactory(factory);
    return gateway;
}

@Bean
public AbstractClientConnectionFactory clientConnectionFactory() {
    return new TcpNetClientConnectionFactory(“123.456.789.0”, 5555);
}

我的理解是调用 sendMessage 函数会将请求消息放在“sendMessage”通道上。然后，该通道会将其传递给 tcpOutboundGateway 服务激活器，该服务激活器将处理消息的发送，并最终将服务器的响应作为 sendMessage 函数的返回值返回。在单一的预定义服务器连接的情况下，此解决方案对我来说效果很好。

我的问题是如何以一种可以支持一组可变的唯一主机/端口的方式动态创建新的消息网关和服务激活器？更具体地说，@MessageGateway 和 @ServiceActivator 注释在后台为我们做了什么？我需要做什么才能复制该功能？

编辑：

所以经过一些试验后，我找到了这个似乎可以解决问题的解决方案......

// Define the Message Gateway without any annotations
public interface MyMessageGateway {
    byte[] sendMessage(String message);
}

...

// Use the GatewayProxyFactoryBean to replicate the functionality of the @MessageGateway annotation
// context is my instance of a ConfigurableApplicationContext
GatewayProxyFactoryBean gpfb = new GatewayProxyFactoryBean(SenderGateway.class);
gpfb.setDefaultRequestChannel(“sendMessage”);
context.getBeanFactory().registerSingleton(“MyMessageGateway”, gpfb);
context.getBeanFactory().initializeBean(gpfb, “MyMessageGateway”);

// Create and register the ClientConnectionFactory Bean within the Application Context
AbstractClientConnectionFactory clientConnectionFactory = new TcpNetClientConnectionFactory(“123.456.789.0”, 5000);
context.getBeanFactory().registerSingleton(“ClientConnectionFactory”, clientConnectionFactory);
context.getBeanFactory().initializeBean(clientConnectionFactory, “ClientConnectionFactory”);

// Create and register the TcpOutboundGateway Bean within the Application Context
TcpOutboundGateway gateway = new TcpOutboundGateway();
gateway.setConnectionFactory(clientConnectionFactory);
context.getBeanFactory().registerSingleton(“TcpOutboundGateway”, tcpOutboundGateway);
context.getBeanFactory().initializeBean(tcpOutboundGateway, “TcpOutboundGateway”);

// Create and register the Request Channel to connect the Message Gateway and the TCP Outbound Gateway
// This should replicate the functionality of the @ServiceActivator annotation
DirectChannel sendMessage = new DirectChannel();
sendMessage.setBeanName(“sendMessage”);
context.getBeanFactory().registerSingleton(“sendMessage”, sendMessage);
context.getBeanFactory().initializeBean(sendMessage, “sendMessage”);

// Subscribe the TCP Outbound Gateway to the new Message Channel (sendMessage)
// This should replicate the functionality of the @ServiceActivator annotation
sendMessage.subscribe(tcpOutboundGateway);

// Start the ClientConnectionFactory
// This seems to be getting done automatically in the non-dynamic implementation above
clientConnectionFactory.start();

此实现允许消息通过消息网关和 TCP 出站网关以与上述带注释实现相同的方式发送（使用为 MyMessageGateway 接口定义的 sendMessage 函数）。我发现为了将这种方法用于多个主机/端口组合，您需要通过 context.getBeanFactory.getBean() 获取所需的消息网关。

我很好奇这种方法/实现是否有任何缺陷？

Answer 1

唯一简单的方法是考虑使用 Spring Integration 提供的带有 Java DSL 的动态 IntegrationFlows：https://docs.spring.io/spring-integration/docs/current/reference/html/#java-dsl-runtime-flows

我们还为类似的动态 TCP 客户端 用例提供了一个全面的示例：https://github.com/spring-projects/spring-integration-samples/tree/master/advanced/dynamic-tcp-client