Spring Integration Java DSL: How to continue after error situation with the split and the aggregate methods?

Question

My program does the following in the high level

Task 1
  get the data from the System X
  the Java DSL split
    post the data to the System Y
    post the reply data to the X
  the Java DSL aggregate
Task 2
  get the data from the System X
  the Java DSL split
    post the data to the System Y
    post the reply data to the X
  the Java DSL aggregate
...

The problem is that when one post the data to the System Y sub task fails, the error message is correctly send back to the System X, but after that any other sub tasks or tasks are not executed.

My error handler does this:

...
Message<String> newMessage = MessageBuilder.withPayload("error occurred")
                .copyHeadersIfAbsent(message.getPayload().getFailedMessage().getHeaders()).build();
...
Set some extra headers etc. 
...
return newMessage;

What could be the problem?

Edit:

I debugged the Spring Integration. In the error situation only first error message comes to the method AbstractCorrelatingMessageHandler.handleMessageInternal. Other successfull and failing messages not come to the method.

If there are not errors all the messages come to the method and finally the group is released.

What could be wrong in my program?

Edit 2:

This is working:

Added the advice for the Http.outboundGateway:

.handle(Http.outboundGateway(...,
                    c -> c.advice(myAdvice()))

and the myAdvice bean

@Bean
private Advice myAdvice() {
    return new MyAdvice();
}

and the MyAdvice class

public class MyAdvice<T> extends AbstractRequestHandlerAdvice {
@SuppressWarnings("unchecked")
@Override
protected Object doInvoke(final ExecutionCallback callback, final Object target, final Message<?> message)
        throws Exception {
    ...

    try {
        result = (MessageBuilder<T>) callback.execute();
    } catch (final MessageHandlingException e) {
        take the exception cause for the new payload
    }

    return new message with the old headers and replyChannel header and result.payload or the exception cause as a payload
}

}

Answer 1

There is nothing wrong with your program. That's exactly how regular loop works in Java. To catch exception for each iteration and continue with other remaining item you definitely need a try..catch in the Java loop. So, something similar you need to apply here for the splitter. It can be achieved with the ExpressionEvaluatingRequestHandlerAdvice, an ExectutorChannel as an output from the splitter or with the gateway call via service activator on the splitter output channel.

Since the story is about an aggregator afterward, you still need to finish a group somehow and this can be done only with some error compensation message to be emitted from the error handling to return back to the aggregator's input channel. In this case you need to ensure to copy request headers from the failedMessage of the MessagingException thrown to the error flow. After aggregation of the group you would need to sever messages with error from the normal ones. That can be done only with the special payload or you may just have an exception as a payload for the proper distinguishing errors from normal messages in the final result from the aggregator.