java - 具有两个来源的 Spring 集成流程

Question

我尝试创建一个流程，它从 2 个源(1 个 mqtt 和一个来自用户服务交互)获取消息，并生成消息到另一个 mqtt。事实上，我尝试使用这个答案:How to crate Spring Integration Flow from two MessageProducerSpec?

这是我的结果:

@Bean
public IntegrationFlow mqttInFlow() {
    return IntegrationFlows.from(mqttInbound())
            .channel("mainMessageChannel")
            .get();
}

@Bean
public IntegrationFlow mqttTestMessageFlow() {
    return IntegrationFlows.from(messageService.testInbound())
            .channel("mainMessageChannel")
            .get();
}

@Bean
public IntegrationFlow mainMessageFlow() {
    return IntegrationFlows.from("mainMessageChannel")
            .handle(eventServiceHandler())
            .split(operationSplitter())
            .handle(mqttOutbound())
            .get();
}

但是我有以下错误:

java.lang.IllegalStateException: 'outputChannel' or 'outputChannelName' is required
    at org.springframework.util.Assert.state(Assert.java:70)
    at org.springframework.integration.endpoint.MessageProducerSupport.afterSingletonsInstantiated(MessageProducerSupport.java:136)

Answer 1

那么，您必须在那些 MessageProducerSupport 定义中使用它，而不是像 channel("mainMessageChannel") 那样:

@Bean
MessageProducerSupport mqttInbound() {
   ...
   adapter.setOutputChannelName("mainMessageChannel");
   ...
}

@Bean
MessageProducerSupport testInbound() {
   ...
   adapter.setOutputChannelName("mainMessageChannel");
   ...
}

或者...只是不要对它们进行 @Bean 注释，Java DSL 会处理它们的声明!