RequestFactory: error.getExceptionType() returns null in Receiver#onFailure

问题

In the server side i have:

public void throwException() throws Exception {
        throw new NullPointerException("fslkdjflks");
}

in the client side i have:

_requestFactory.myService().throwException().fire(new Receiver<Void>() {

            @Override
            public void onSuccess(Void response) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onFailure(ServerFailure error) {
                // TODO Auto-generated method stub
                Window.alert(error.getExceptionType() + " " + error.getMessage());

            }

        });

error.getExceptionType() returns null and not the type of the exception. Any idea why?

Thanks, Gilad.

回答1:

The default ExceptionHandler (DefaultExeptionHandler) does not populate the exceptionType and stackTraceString. If you want them, you have to provide your own ExceptionHandler by extending RequestFactoryServlet.

回答2:

Addition to Thomas post, a link how to implement it.

Implement this and you get your StackTrace and find the Problem: http://cleancodematters.com/2011/05/29/improved-exceptionhandling-with-gwts-requestfactory/

Takes five minutues and saves you much time now and in future.

来源：https://stackoverflow.com/questions/10471294/requestfactory-error-getexceptiontype-returns-null-in-receiveronfailure