JAX-RS - ExceptionMapper Examples

package com.logicbig.example;

import javax.ws.rs.core.Response;
import javax.ws.rs.ext.ExceptionMapper;
import javax.ws.rs.ext.Provider;

@Provider
public class InvalidIdExceptionMapper
        implements ExceptionMapper<InvalidIdException> {


    @Override
    public Response toResponse(InvalidIdException exception) {
        return Response.status(Response.Status.NOT_FOUND)
                       .entity(prepareMessage(exception))
                       .type("text/plain")
                       .build();
    }

    private String prepareMessage(InvalidIdException exception) {

        String m = exception.getMessage();
        String r = "Invalid request.\n";
        r += String.format("Error Message: %s.%nError Type: %s.%n"
                        + "You may contact admin@example.com for more questions.",
                m, exception.getClass());
        return r;
    }
}

import javax.validation.ConstraintViolation;
import javax.validation.ConstraintViolationException;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.ExceptionMapper;
import javax.ws.rs.ext.Provider;

@Provider
public class MyExceptionMapper
                 implements ExceptionMapper<ConstraintViolationException> {

    @Override
    public Response toResponse(final ConstraintViolationException exception) {
        return Response.status(Response.Status.BAD_REQUEST)
                       .entity(prepareMessage(exception))
                       .type("text/plain")
                       .build();
    }

    private String prepareMessage(ConstraintViolationException exception) {
        String msg = "";
        for (ConstraintViolation<?> cv : exception.getConstraintViolations()) {
            msg+=cv.getPropertyPath()+" "+cv.getMessage()+"\n";
        }
        return msg;
    }
}