java - 错误 channel 中的 MessageHandlingException 消息

Question

我编写了一个异常处理程序类，它查看默认的 Spring Integration errorChannel对于类型为 Message<TradeProcessingContext> message 的传入消息:

@Slf4j
public class ExceptionHandler {

    @Autowired
    private ExceptionDAO exceptionDAO;


    @ServiceActivator(inputChannel = DEFAULT_ERROR_CHANNEL)
    public void handleTradeError(Message<TradeProcessingContext> message) {

        TradeProcessingContext tradeProcessingContext = message.getPayload();

        if (tradeProcessingContext != null) {
          //store in database
        }
    }

}

我的处理程序实现如下:

@Slf4j
@MessageEndpoint
public class ChildHandler extends ParentHandler {

    @Autowired
    private SomeDAO someDAO;

    @ServiceActivator(inputChannel = INPUT_CHANNEL, outputChannel = DEFAULT_ERROR_CHANNEL)
    public Message<TradeProcessingContext> handle(final Event event) {
        return process(event);
    }

    @Override
    protected TradeDAO getDAO() {
        return someDAO;
    }
}

调用父级 process()

public abstract class ParentHandler implements Handler {

    @Resource
    private SomeService service;


    public Message<TradeProcessingContext> process(final Event event) {

        TradeProcessingContext tradeProcessingContext = new TradeProcessingContext();

        //set initial context

        try {
            List<Trade> trades = getDAO().findByEventId(event.getEventId());
            for (Trade trade : trades) {
                tradeProcessingContext.setRef(trade.getRef());
                Future<TradeProcessingContext> thread = service.doSomething(trade, tradeProcessingContext);
                tradeProcessingContext = thread.get();
            }
        } catch (Exception e) {
            return MessageBuilder.withPayload(tradeProcessingContext).build();
        }

        return null;
    }

我知道我可以获得 org.springframework.messaging.MessageHandlingException: nested exception is java.lang.ClassCastException当类型为Message<MessageHandlingException> message时在handleTradeError() .

我如何改进此方法，以便也解决此类错误或底层 tradeprocessingContext也是从这个类型中提取出来的？

Answer 1

错误 channel 获取具有 Throwable 负载的 ErrorMessage。通常 Throwable 是一个消息处理异常，原始消息位于 failedMessage 属性中，异常位于原因中。