ExceptionHandler.java

/*
 * Copyright 2016 Studentmediene i Trondheim AS
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package no.dusken.momus.exceptions;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.security.core.AuthenticationException;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.view.json.MappingJackson2JsonView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * All exceptions while processing a request will be sent to this handler.
 * Will make a proper http response out of it, can log it here etc.
 */
public class ExceptionHandler implements HandlerExceptionResolver {

    Logger logger = LoggerFactory.getLogger(getClass());

    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse response, Object o, Exception e) {

        if (e instanceof RestException) { // If it's our exception, we know how to handle it and has set a status
            response.setStatus(((RestException) e).getStatus());
        } else if(e instanceof AccessDeniedException) { // let Spring handle it by throwing it again
            throw (AccessDeniedException) e;
        } else if (e instanceof AuthenticationException) { // let Spring handle it, is a failed login
            throw (AuthenticationException) e;
        } else { // Something else, log it and set status to internal server error
            response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            logException(e);
        }

        ModelAndView mav = new ModelAndView(new MappingJackson2JsonView());
        mav.addObject("error", e.getMessage());

        return mav;
    }

    private void logException(Exception e) {
        logger.error("Exceptionhandler caught:", e);
    }
}