Spring DSL：向JMS队列发送错误消息。得到一个错误'One-way'MessageHandler'，并且不适合配置'Output Channel''

Question

is a one-way 'MessageHandler' and it isn't appropriate to configure 'outputChannel'. This is the end of the integration flow.

@Autowired
private JmsMessagingTemplate jmsMessagingTemplate;

@Bean
public Queue errorQueue() {
    return new ActiveMQQueue(fatalQueue);
}
@Bean
public DirectChannel errorChannel() {
    return new DirectChannel();
}
@Bean
public IntegrationFlow handleErrors() {
    return IntegrationFlows
            .from(errorChannel())
            .handle(x -> System.out.println("error handling invoked.x="+x))
            .handle(Jms.outboundAdapter(jmsMessagingTemplate.getConnectionFactory()).destination(fatalQueue))
            .get();
}

stacktrace说：

Caused by: org.springframework.beans.factory.BeanCreationException: The 'currentComponent' (MessageReceiver$$Lambda$1/1495414981@76c52298) is a one-way 'MessageHandler' and it isn't appropriate to configure 'outputChannel'. This is the end of the integration flow.
  at org.springframework.integration.dsl.IntegrationFlowDefinition.registerOutputChannelIfCan(IntegrationFlowDefinition.java:2630) ~[spring-integration-java-dsl-1.1.0.RELEASE.jar:na]
  at org.springframework.integration.dsl.IntegrationFlowDefinition.register(IntegrationFlowDefinition.java:2554) ~[spring-integration-java-dsl-1.1.0.RELEASE.jar:na]
  at org.springframework.integration.dsl.IntegrationFlowDefinition.handle(IntegrationFlowDefinition.java:1136) ~[spring-integration-java-dsl-1.1.0.RELEASE.jar:na]
  at org.springframework.integration.dsl.IntegrationFlowDefinition.handle(IntegrationFlowDefinition.java:1116) ~[spring-integration-java-dsl-1.1.0.RELEASE.jar:na]
  at org.springframework.integration.dsl.IntegrationFlowDefinition.handle(IntegrationFlowDefinition.java:863) ~[spring-integration-java-dsl-1.1.0.RELEASE.jar:na]

Answer 1

你的问题在这里：

.handle(x -> System.out.println("error handling invoked.x="+x))

StackTrace确切地谈到了这一点。

这并不令人惊讶。您的Lambda如下所示：

.handle(new MessageHandler() {

        public void handleMessage(Message<?> message) throws MessagingException {
               System.out.println("error handling invoked.x="+x);
        }
})

.handle((p, h) -> {
        System.out.println("error handling invoked.x=" + new MutableMessage(p, h));
        return p;
 })