Mule private flows and separation of concerns

1
votes

I have a requirement which I want to solve using Mule. My flow design follows like:

  • A main-flow with request-response HTTP inbound endpoint. After applying couple of transformations on the current payload this main flow invokes two private flows namely private-flow1 and private-flow2, which are mule private flows whose processing strategy is synchronous.
  • The private-flow1 invokes an external service using request-response HTTP outbound endpoint.
  • The private-flow2 places the response from the external service on Database using Database Connector.

If there is any exception in each of the private flows, I want to handle them in the corresponding private flow itself using Catch Exception Strategy.

I have this design to separate the concerns, so that each flow performs a single responsibility.

Suppose there is an exception like IOException, SQLException or any, in any one of the private flows, how can I re-throw my custom exception, for example, org.mycompany.CustomException including the underlying cause. So main-flow will have to handle only org.mycompany.CustomException and build the related exception response.

Say for example, if private-flow1 throws org.mycompany.CustomException which is caused by IOException, the realted exception response would be:

{"exceptionMessage" : External Service unavailable, "exceptionCode" : 101}

and, if private-flow2 throws org.mycompany.CustomException which is caused by SQLException, the realted exception response would be

{"exceptionMessage" : Database unavailable, "exceptionCode" : 102}

1
exception-handlingmule

1 Answers

1
votes

Each private flow will have their own exception strategy and you can throw an exception using Groovy component from the flows ..

Here is a link how to do it :- How do I force an exception in mule

for custom exception create java-class which would extend DefaultMessagingExceptionStrategy

Update:- An example to use custom-exception-strategy:- Why is Mule exception strategy so chatty?