Error propagation in route

[Sven Bauhan <sv...@ast.dfs.de>]

Hi,

I try to understand how to handle with errors in messages within a camel 
route.

I have the following route in a Camel context component:
             FailureReceiveProcessor fails = new FailureReceiveProcessor();
onException(MessageReceiveException.class).handled(false).process(fails);
onException(MessageAggregateException.class).handled(true).process(fails);
onException(NumberFormatException.class).handled(true).process(fails);
onException(UnmarshalException.class).handled(true).process(fails);
onException(ClosedCorrelationKeyException.class).handled(true).process(fails);

             from(Endpoints.SEGMENT_IN.seda())
                             .process(first_check)
                             .unmarshal(usedFormat)
                             .process(bean2msg)
                             .choice()
.when(header(HeaderKeys.TYPE.key()).isEqualTo(MSG.UserMessageType.RESP.toString()))
                             .process(send_controller)
                             .otherwise()
                             .aggregate(header(HeaderKeys.MID.key()), 
aggregation).completionPredicate(aggregation)
.closeCorrelationKeyOnCompletion(CLOSED_CORRELATION_KEY_CACHE_SIZE)
.completionTimeout(getT_seg()).discardOnCompletionTimeout()
                             .to(Endpoints.MESSAGE_OUT.seda());

In the process bean2msg I check the unmarshalled message and put the 
meta data into headers of the camel message and the payload in the body. 
When the message is incorrect I throw a MessageReceiveException.
The pitfall is that the aggregator has be informed of the incorrect 
message; cause if one segment of a message is incorrect, the previous 
segments shall be withdrawn and the sender sends all segments again.

The exception handling onException(MessageReceiveException) can be set 
to false, but this means the exception is propagated to the application. 
If it is set handled(true), the exception will not be propagated, but 
also the message is not routed further to the aggregator.

Another way could be to set the fault flag on the Message; but I did not 
understand the concept completely yet.
If I set msg.setFault() in the bean2msg Processor, is the message routed 
to the aggregator? Can I ask msg.isFault() then and throw the 
MessageAggregatorException there?

Another idea is to set a property on the Exchange or a special header 
field on the Message. But I think this would be a misuse of the Camel 
error handling strategy.

Thanks for advices,
Sven