Apache CXF - Handle missing path parameters in an operation

Question

I am using apache cxf for Jax-rs implementation in my project. I have a service defined with the following address: http://ip:port/myservice/ {operation}

consider an operation for this server defined as below

@Override
@GET
@Path("operation1/{x}/{y}")
@Produces("application/xml")
public String operation1(@PathParam("x") final String x, @PathParam("y") final String y) {
    return null;
}

In the scenario where the requester makes a request with some operation name that is not defined in myservice, it will return 404 which is expected behavior. But i am getting the same 404 in cases where operation name is correctly requested but path parameters are not. I would like to create a proper error if any of {x} or {y} path param is missing in a request. But i cannot find a graceful way where i can handle exceptions as per the operations. CXF never maps to the operation in such cases.

I have this exception mapper:

public class ClientExceptionMapper implements ExceptionMapper<ClientErrorException> {

@Override
public Response toResponse(final ClientErrorException exception) {
    return Response.status(Response.Status.FORBIDDEN).entity("Invalid request").build();

}

}

Which will handle all error cases but it doesn't provide any information as to what URL was requested in the exception. Is there a way where i can handle exceptions differently for different operations in cases when path parameters are not defined ? For eg: I would like to handle following request with some custom logic defined for operation1 only. http://ip:port/myservice/operation1/20

Answer 1

I see two solutions for your case.
1) Move your path params to query param. @QueryParam
2) Create a filter and map it to url operation1/*

Answer 2

While finding solution for my scenario where i need to validate path parameters, i found this link which suggests a nice workaround for my problem. Although its just a hack and might not be a good idea to implement in existing code, you can consider it if you need to play around with path parameters within your respective operation.