Error handling with CXF interceptors - changing the response message

Question

I'm trying to handle errors coming from my backend. The handleMessage() is called if an error occurs but the content is an instance of XmlMessage. I would like to change it to my own response - just set the response code and add some message.

I haven't found any proper documentation which could tell me how to do this...

These axamples are for REST but I'd like to manage this thing in SOAP too.

interceptor

public class ErrorHandlerInterceptor extends AbstractPhaseInterceptor<Message> {

    public ErrorHandlerInterceptor() {
        super(Phase.POST_LOGICAL);
    }

    @Override
    public void handleMessage(Message message) throws Fault {
        Response response = Response
            .status(Response.Status.BAD_REQUEST)
            .entity("HOW TO GET A MESSAGE FROM AN EXCEPTION IN HERE???")
            .build();
        message.getExchange().put(Response.class, response);
    }

}

context.xml

<bean id="errorHandlerInterceptor"
    class="cz.cvut.fit.wst.server.interceptor.ErrorHandlerInterceptor" />

<jaxrs:server address="/rest/">
    <jaxrs:serviceBeans>
        <ref bean="restService" />
    </jaxrs:serviceBeans>
    <jaxrs:outFaultInterceptors>
        <ref bean="errorHandlerInterceptor" />
    </jaxrs:outFaultInterceptors>
</jaxrs:server>

Solution 1

And here's the other piece of your puzzle. You're already using JAX-RS, so why not use JAX-WS as well?

This thread and this blog post cover mapping Exceptions into SOAP faults. Short and sweet:

The JAX-WS 2.0 specification demands that the exception annotated with @WebFault must have two constructors and one method [getter to obtain the fault information]:

WrapperException(String message, FaultBean faultInfo)
WrapperException(String message, FaultBean faultInfo, Throwable cause)
FaultBean getFaultInfo()

The WrapperException is replaced by the name of the exception, and FaultBean is replaced by the class name that implements the fault bean. The fault bean is a Java bean that contains the information of the fault and is used by the Web service client to know the cause for the fault.

And there's your mapping. Simply specify implementations of the above signatures in the context of @WebFault and your SOAP API should map these happily. Obviously, the links contain more details.

Solution 2

If you're using JAX-RS, why not setup an exception mapper, and then use that mapper to handle the response.

A simple example:

@Provider
@Produces(MediaType.APPLICATION_JSON)
public class MyExceptionMapper implements
        ExceptionMapper<MyException> {

    @Override
    public Response toResponse(MyException e) {
        return Response.status(Status.NOT_FOUND).build();
    }

}

Then you would need to register the provider in the jaxrs serve by adding:

<jaxrs:providers>
    <bean class="com.blah.blah.blah.blah.MyExceptionMapper"/>  
</jaxrs:providers>

in the server config in the context. With that you have full access to the exception, and can get whatever you want from it.

Comments

[user219882]

And what if I'd like to use SOAP? How can I handle that? Same as for the JAX-RS or do I have to you interceptor?

[mjwenk]

For soap, I think you have to use an interceptor. I wasn't ever able to figure out exactly what I needed to do to get to work in CXF's soap stuff. Fortunately for me it wasn't much of a problem, but the jax-rs way seems much nicer.

[user219882]

Thank you. I don't accept your answer yet in order to divide the reputation between you two

[MrGomez]

@Tomas While the effort is noble (I'm glad I helped!), that, unfortunately, isn't how the bounty system works (details). I'm uncomfortable with reconciling this for you because I have a stake in the result, but the option exists to grant an additional bounty if you feel two answers are deserving of it. Sorry for the trouble; I didn't write the system. :)

[user219882]

Oh, that's too bad. I decided to do this: I give the bounty to mjwenk because the reputation helps him more than you and accept your answer since you have links to both REST and SOAP. I guess it is the only fair way (or at least a little bit). Thank you for mentioning it...

[MrGomez]

@Tomas Entirely reasonable! Thanks for being above board about it and for letting me know. :)

[Bhuvan]

What if I have a following scenario. I have an interceptor that performs validation. And I have an Exception handler as well. If I want to throw my custom exception from the interceptor, will my exception handler's toResponse method be invoked?

[Bhuvan]

You can answer on this question stackoverflow.com/questions/17079790/…

[Krayo]

If auto-scan has been set (<jaxrs:server address="/rs" basePackages="com.abc.service" />), then no registration required.

[Marcin Erbel]

Is there any way to catch exception from interceptor into exception mapper? I can't do it: stackoverflow.com/questions/37984617/…

[Max]

should be noted: this solution will work anyway but override jackson data parser / databinding at the end