@Header 注释未按预期工作

Question

我正在开发一个 spring 集成项目（1.0.2），但无法让 @Header 注释工作。

这是我的服务激活器：

@Component
public class MyTransformer {
    @ServiceActivator(inputChannel = "inChannel", outputChannel = "outChannel")
    public String transform(final Message<?> message,
                            @Header(value = "eventId") final Long id,
                            @Header(value = "error", required = false) final Throwable throwable) {
        return throwable == null
                ? "event [" + eventId +"]"
                : "event [" + eventId +"] error: " + throwable.getMessage();
    }
}

这是错误消息：

Caused by: java.lang.IllegalArgumentException: Wrong number of arguments. Expected types {class java.lang.Object, class java.lang.Long, class java.lang.Throwable}, but received values {[Payload=parp][Headers={eventId=888Foo, error=java.lang.IllegalArgumentException: Invalid message content parp, springintegration_timestamp=1277803938244, springintegration_id=726d0769-bd27-4d95-a9ea-640c1f807065}]}.
    at org.springframework.integration.util.DefaultMethodInvoker.invokeMethod(DefaultMethodInvoker.java:71)
    at org.springframework.integration.handler.MessageMappingMethodInvoker.doInvokeMethod(MessageMappingMethodInvoker.java:160)
    at org.springframework.integration.handler.MessageMappingMethodInvoker.invokeMethod(MessageMappingMethodInvoker.java:107)
    at org.springframework.integration.handler.ServiceActivatingHandler.handleRequestMessage(ServiceActivatingHandler.java:49)
    at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:91)
    at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:59)

我做错了什么？

Answer 1

当然，Event Id 应该是 String，而不是 Long。

这样就解决了。