Question

I’m looking for way to present custom error pages if no matching JAX-RS resource was found. My idea was to use an ExceptionMapper, but I don’t know the exception class to use:

@Provider
public class NotFoundMapper implements ExceptionMapper<WHATEXCEPTION?> {
  ...
}

RestEasy has a proprietary NotFoundException, but is there a way that works with Jersey, too? Ideally a standard compliant way?

Answer 1

Do you mean if your rest service is listening under localhost/rest then localhost/rest/asdf should return you a customized 404 page? It is specific to the JAX-RS engine, you must check the source code of Jersey. For example CXF throws a WebApplicationException, but it does not provide any way to customize it. See JAXRSInInterceptor.processRequest() line 156 to see how it is done :

    org.apache.cxf.common.i18n.Message errorMsg = 
        new org.apache.cxf.common.i18n.Message("NO_ROOT_EXC", 
                                           BUNDLE,
                                           message.get(Message.REQUEST_URI),
                                           rawPath);
    LOG.warning(errorMsg.toString());
    Response resp = JAXRSUtils.createResponse(resource, message, errorMsg.toString(), 
            Response.Status.NOT_FOUND.getStatusCode(), false);
    throw new WebApplicationException(resp);

To summarize there is no nice and standard way, you can try to use a request filter or an ExceptionMapper