Redirect http 500 error to 400

Question

When my server receives incomplete xml it returns a 500 Internal Server Error back due to the default handling for java.lang.IllegalArgumentException. I can override the html page that is returned but I also need to override the error code and make it 400 to follow our documented spec. Is there a way to override the error code in JSF-2.0? We are using JAXB for the xml handling.

Answer 1

I ended up using an ExceptionMapper like so:

@Provider
public class ClassCastExceptionMapper implements ExceptionMapper<java.lang.ClassCastException> {

    @Override
    public Response toResponse(java.lang.ClassCastException arg0) {
        return Response.status(Response.Status.BAD_REQUEST).build();
    }
}

Answer 2

Depends on where it's been thrown and if it's wrapped in another exception. It's hard to give a perfect-fit answer based on the information provided as far.

But to the point, to send a response error with the right status using JSF2, use ExternalContext#responseSendError(). E.g.

try {
    // ... ???
} catch (IllegalArgumentException e) {
    externalContext.responseSendError(400, e.getMessage());
    e.printStackTrace(); // Or use logger.
}

Or equivalently in a servlet filter, use HttpServletResponse#sendError()

try {
    // ... ???
} catch (IllegalArgumentException e) {
    response.sendError(400, e.getMessage());
    e.printStackTrace(); // Or use logger.
}