com.springsource.greenhouse.home.GlobalExceptionResolver.java Source code

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Here is the source code for com.springsource.greenhouse.home.GlobalExceptionResolver.java

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/*
 * Copyright 2010 the original author or authors.
 *
 * 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 com.springsource.greenhouse.home;

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

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.dao.EmptyResultDataAccessException;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver;
import org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver;

/**
 * Handles Exceptions that are not handled at the Application Controller level.
 * Applies the global exception handling policy for the application.
 * An AccountNotConnectedException results in a 412.
 * An EmptyResultDataAccessException results in a 404.
 * Delegates to {@link ResponseStatusExceptionResolver} as a first fallback.
 * Delegates to {@link DefaultHandlerExceptionResolver} as a final fallback.
 * @author Keith Donald
 */
@Component
public class GlobalExceptionResolver implements HandlerExceptionResolver {

    private static final Logger logger = LoggerFactory.getLogger(GlobalExceptionResolver.class);

    private final ResponseStatusExceptionResolver annotatedExceptionHandler = new ResponseStatusExceptionResolver();

    private final DefaultHandlerExceptionResolver defaultExceptionHandler = new DefaultHandlerExceptionResolver();

    public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler,
            Exception ex) {
        try {
            if (ex instanceof EmptyResultDataAccessException) {
                return handleEmptyResultDataAccessException((EmptyResultDataAccessException) ex, request, response,
                        handler);
            }
        } catch (Exception e) {
            logger.warn("Handling of [" + ex.getClass().getName() + "] resulted in Exception", ex);
            return null;
        }
        ModelAndView result = annotatedExceptionHandler.resolveException(request, response, handler, ex);
        if (result != null) {
            return result;
        }
        return defaultExceptionHandler.resolveException(request, response, handler, ex);
    }

    // internal helpers

    private ModelAndView handleEmptyResultDataAccessException(EmptyResultDataAccessException ex,
            HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        response.sendError(HttpServletResponse.SC_NOT_FOUND);
        return new ModelAndView();
    }

}