/*
* Copyright 2002-2017 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 org.springframework.web.servlet.mvc.annotation;
import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.context.MessageSource;
import org.springframework.context.MessageSourceAware;
import org.springframework.context.i18n.LocaleContextHolder;
import org.springframework.core.annotation.AnnotatedElementUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.server.ResponseStatusException;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver;
/**
* A {@link org.springframework.web.servlet.HandlerExceptionResolver
* HandlerExceptionResolver} that uses the {@link ResponseStatus @ResponseStatus}
* annotation to map exceptions to HTTP status codes.
*
* <p>This exception resolver is enabled by default in the
* {@link org.springframework.web.servlet.DispatcherServlet DispatcherServlet}
* and the MVC Java config and the MVC namespace.
*
* <p>As of 4.2 this resolver also looks recursively for {@code @ResponseStatus}
* present on cause exceptions, and as of 4.2.2 this resolver supports
* attribute overrides for {@code @ResponseStatus} in custom composed annotations.
*
* <p>As of 5.0 this resolver also supports {@link ResponseStatusException}.
*
* @author Arjen Poutsma
* @author Rossen Stoyanchev
* @author Sam Brannen
* @since 3.0
* @see ResponseStatus
* @see ResponseStatusException
*/
public class ResponseStatusExceptionResolver extends AbstractHandlerExceptionResolver implements MessageSourceAware {
private MessageSource messageSource;
@Override
public void setMessageSource(MessageSource messageSource) {
this.messageSource = messageSource;
}
@Override
protected ModelAndView doResolveException(HttpServletRequest request, HttpServletResponse response,
Object handler, Exception ex) {
try {
if (ex instanceof ResponseStatusException) {
return resolveResponseStatusException((ResponseStatusException) ex, request, response, handler);
}
ResponseStatus status = AnnotatedElementUtils.findMergedAnnotation(ex.getClass(), ResponseStatus.class);
if (status != null) {
return resolveResponseStatus(status, request, response, handler, ex);
}
if (ex.getCause() instanceof Exception) {
ex = (Exception) ex.getCause();
return doResolveException(request, response, handler, ex);
}
}
catch (Exception resolveEx) {
logger.warn("Handling of @ResponseStatus resulted in Exception", resolveEx);
}
return null;
}
/**
* Template method that handles the {@link ResponseStatus @ResponseStatus} annotation.
* <p>The default implementation delegates to {@link #applyStatusAndReason}
* with the status code and reason from the annotation.
* @param responseStatus the {@code @ResponseStatus} annotation
* @param request current HTTP request
* @param response current HTTP response
* @param handler the executed handler, or {@code null} if none chosen at the
* time of the exception, e.g. if multipart resolution failed
* @param ex the exception
* @return an empty ModelAndView, i.e. exception resolved
*/
protected ModelAndView resolveResponseStatus(ResponseStatus responseStatus, HttpServletRequest request,
HttpServletResponse response, Object handler, Exception ex) throws Exception {
int statusCode = responseStatus.code().value();
String reason = responseStatus.reason();
return applyStatusAndReason(statusCode, reason, response);
}
/**
* Template method that handles an {@link ResponseStatusException}.
* <p>The default implementation delegates to {@link #applyStatusAndReason}
* with the status code and reason from the exception.
* @param ex the exception
* @param request current HTTP request
* @param response current HTTP response
* @param handler the executed handler, or {@code null} if none chosen at the
* time of the exception, e.g. if multipart resolution failed
* @return an empty ModelAndView, i.e. exception resolved
* @since 5.0
*/
protected ModelAndView resolveResponseStatusException(ResponseStatusException ex,
HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
int statusCode = ex.getStatus().value();
String reason = ex.getReason();
return applyStatusAndReason(statusCode, reason, response);
}
/**
* Apply the resolved status code and reason to the response.
* <p>The default implementation sends a response error using
* {@link HttpServletResponse#sendError(int)} or
* {@link HttpServletResponse#sendError(int, String)} if there is a reason
* and then returns an empty ModelAndView.
* @param statusCode the HTTP status code
* @param reason the associated reason (may be {@code null} or empty)
* @param response current HTTP response
* @since 5.0
*/
protected ModelAndView applyStatusAndReason(int statusCode, String reason, HttpServletResponse response)
throws IOException {
if (!StringUtils.hasLength(reason)) {
response.sendError(statusCode);
}
else {
String resolvedReason = (this.messageSource != null ?
this.messageSource.getMessage(reason, null, reason, LocaleContextHolder.getLocale()) :
reason);
response.sendError(statusCode, resolvedReason);
}
return new ModelAndView();
}
}