/*
* Copyright 2002-2011 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.method.annotation;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.transform.Source;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.http.converter.ByteArrayHttpMessageConverter;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.http.converter.xml.SourceHttpMessageConverter;
import org.springframework.http.converter.xml.XmlAwareFormHttpMessageConverter;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.ServletWebRequest;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.method.annotation.ExceptionHandlerMethodResolver;
import org.springframework.web.method.annotation.MapMethodProcessor;
import org.springframework.web.method.annotation.ModelAttributeMethodProcessor;
import org.springframework.web.method.annotation.ModelMethodProcessor;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.HandlerMethodArgumentResolverComposite;
import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
import org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite;
import org.springframework.web.method.support.ModelAndViewContainer;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.View;
import org.springframework.web.servlet.handler.AbstractHandlerMethodExceptionResolver;
/**
* An {@link AbstractHandlerMethodExceptionResolver} that resolves exceptions
* through {@code @ExceptionHandler} methods.
*
* <p>Support for custom argument and return value types can be added via
* {@link #setCustomArgumentResolvers} and {@link #setCustomReturnValueHandlers}.
* Or alternatively to re-configure all argument and return value types use
* {@link #setArgumentResolvers} and {@link #setReturnValueHandlers(List)}.
*
* @author Rossen Stoyanchev
* @since 3.1
*/
public class ExceptionHandlerExceptionResolver extends AbstractHandlerMethodExceptionResolver implements
InitializingBean {
private List<HandlerMethodArgumentResolver> customArgumentResolvers;
private List<HandlerMethodReturnValueHandler> customReturnValueHandlers;
private List<HttpMessageConverter<?>> messageConverters;
private final Map<Class<?>, ExceptionHandlerMethodResolver> exceptionHandlerMethodResolvers =
new ConcurrentHashMap<Class<?>, ExceptionHandlerMethodResolver>();
private HandlerMethodArgumentResolverComposite argumentResolvers;
private HandlerMethodReturnValueHandlerComposite returnValueHandlers;
/**
* Default constructor.
*/
public ExceptionHandlerExceptionResolver() {
StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter();
stringHttpMessageConverter.setWriteAcceptCharset(false); // See SPR-7316
this.messageConverters = new ArrayList<HttpMessageConverter<?>>();
this.messageConverters.add(new ByteArrayHttpMessageConverter());
this.messageConverters.add(stringHttpMessageConverter);
this.messageConverters.add(new SourceHttpMessageConverter<Source>());
this.messageConverters.add(new XmlAwareFormHttpMessageConverter());
}
/**
* Provide resolvers for custom argument types. Custom resolvers are ordered
* after built-in ones. To override the built-in support for argument
* resolution use {@link #setArgumentResolvers} instead.
*/
public void setCustomArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
this.customArgumentResolvers= argumentResolvers;
}
/**
* Return the custom argument resolvers, or {@code null}.
*/
public List<HandlerMethodArgumentResolver> getCustomArgumentResolvers() {
return this.customArgumentResolvers;
}
/**
* Configure the complete list of supported argument types thus overriding
* the resolvers that would otherwise be configured by default.
*/
public void setArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
if (argumentResolvers == null) {
this.argumentResolvers = null;
}
else {
this.argumentResolvers = new HandlerMethodArgumentResolverComposite();
this.argumentResolvers.addResolvers(argumentResolvers);
}
}
/**
* Return the configured argument resolvers, or possibly {@code null} if
* not initialized yet via {@link #afterPropertiesSet()}.
*/
public HandlerMethodArgumentResolverComposite getArgumentResolvers() {
return this.argumentResolvers;
}
/**
* Provide handlers for custom return value types. Custom handlers are
* ordered after built-in ones. To override the built-in support for
* return value handling use {@link #setReturnValueHandlers}.
*/
public void setCustomReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
this.customReturnValueHandlers = returnValueHandlers;
}
/**
* Return the custom return value handlers, or {@code null}.
*/
public List<HandlerMethodReturnValueHandler> getCustomReturnValueHandlers() {
return this.customReturnValueHandlers;
}
/**
* Configure the complete list of supported return value types thus
* overriding handlers that would otherwise be configured by default.
*/
public void setReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
if (returnValueHandlers == null) {
this.returnValueHandlers = null;
}
else {
this.returnValueHandlers = new HandlerMethodReturnValueHandlerComposite();
this.returnValueHandlers.addHandlers(returnValueHandlers);
}
}
/**
* Return the configured handlers, or possibly {@code null} if not
* initialized yet via {@link #afterPropertiesSet()}.
*/
public HandlerMethodReturnValueHandlerComposite getReturnValueHandlers() {
return this.returnValueHandlers;
}
/**
* Set the message body converters to use.
* <p>These converters are used to convert from and to HTTP requests and responses.
*/
public void setMessageConverters(List<HttpMessageConverter<?>> messageConverters) {
this.messageConverters = messageConverters;
}
/**
* Return the configured message body converters.
*/
public List<HttpMessageConverter<?>> getMessageConverters() {
return messageConverters;
}
public void afterPropertiesSet() {
if (this.argumentResolvers == null) {
List<HandlerMethodArgumentResolver> resolvers = getDefaultArgumentResolvers();
this.argumentResolvers = new HandlerMethodArgumentResolverComposite().addResolvers(resolvers);
}
if (this.returnValueHandlers == null) {
List<HandlerMethodReturnValueHandler> handlers = getDefaultReturnValueHandlers();
this.returnValueHandlers = new HandlerMethodReturnValueHandlerComposite().addHandlers(handlers);
}
}
/**
* Return the list of argument resolvers to use including built-in resolvers
* and custom resolvers provided via {@link #setCustomArgumentResolvers}.
*/
protected List<HandlerMethodArgumentResolver> getDefaultArgumentResolvers() {
List<HandlerMethodArgumentResolver> resolvers = new ArrayList<HandlerMethodArgumentResolver>();
// Type-based argument resolution
resolvers.add(new ServletRequestMethodArgumentResolver());
resolvers.add(new ServletResponseMethodArgumentResolver());
// Custom arguments
if (getCustomArgumentResolvers() != null) {
resolvers.addAll(getCustomArgumentResolvers());
}
return resolvers;
}
/**
* Return the list of return value handlers to use including built-in and
* custom handlers provided via {@link #setReturnValueHandlers}.
*/
protected List<HandlerMethodReturnValueHandler> getDefaultReturnValueHandlers() {
List<HandlerMethodReturnValueHandler> handlers = new ArrayList<HandlerMethodReturnValueHandler>();
// Single-purpose return value types
handlers.add(new ModelAndViewMethodReturnValueHandler());
handlers.add(new ModelMethodProcessor());
handlers.add(new ViewMethodReturnValueHandler());
handlers.add(new HttpEntityMethodProcessor(getMessageConverters()));
// Annotation-based return value types
handlers.add(new ModelAttributeMethodProcessor(false));
handlers.add(new RequestResponseBodyMethodProcessor(getMessageConverters()));
// Multi-purpose return value types
handlers.add(new ViewNameMethodReturnValueHandler());
handlers.add(new MapMethodProcessor());
// Custom return value types
if (getCustomReturnValueHandlers() != null) {
handlers.addAll(getCustomReturnValueHandlers());
}
// Catch-all
handlers.add(new ModelAttributeMethodProcessor(true));
return handlers;
}
/**
* Find an @{@link ExceptionHandler} method and invoke it to handle the
* raised exception.
*/
@Override
protected ModelAndView doResolveHandlerMethodException(HttpServletRequest request,
HttpServletResponse response,
HandlerMethod handlerMethod,
Exception exception) {
if (handlerMethod == null) {
return null;
}
ServletInvocableHandlerMethod exceptionHandlerMethod = getExceptionHandlerMethod(handlerMethod, exception);
if (exceptionHandlerMethod == null) {
return null;
}
exceptionHandlerMethod.setHandlerMethodArgumentResolvers(this.argumentResolvers);
exceptionHandlerMethod.setHandlerMethodReturnValueHandlers(this.returnValueHandlers);
ServletWebRequest webRequest = new ServletWebRequest(request, response);
ModelAndViewContainer mavContainer = new ModelAndViewContainer();
try {
if (logger.isDebugEnabled()) {
logger.debug("Invoking @ExceptionHandler method: " + exceptionHandlerMethod);
}
exceptionHandlerMethod.invokeAndHandle(webRequest, mavContainer, exception);
}
catch (Exception invocationEx) {
logger.error("Failed to invoke @ExceptionHandler method: " + exceptionHandlerMethod, invocationEx);
return null;
}
if (mavContainer.isRequestHandled()) {
return new ModelAndView();
}
else {
ModelAndView mav = new ModelAndView().addAllObjects(mavContainer.getModel());
mav.setViewName(mavContainer.getViewName());
if (!mavContainer.isViewReference()) {
mav.setView((View) mavContainer.getView());
}
return mav;
}
}
/**
* Find the @{@link ExceptionHandler} method for the given exception.
* The default implementation searches @{@link ExceptionHandler} methods
* in the class hierarchy of the method that raised the exception.
* @param handlerMethod the method where the exception was raised
* @param exception the raised exception
* @return a method to handle the exception, or {@code null}
*/
protected ServletInvocableHandlerMethod getExceptionHandlerMethod(HandlerMethod handlerMethod, Exception exception) {
Class<?> handlerType = handlerMethod.getBeanType();
Method method = getExceptionHandlerMethodResolver(handlerType).resolveMethod(exception);
return (method != null ? new ServletInvocableHandlerMethod(handlerMethod.getBean(), method) : null);
}
/**
* Return a method resolver for the given handler type, never {@code null}.
*/
private ExceptionHandlerMethodResolver getExceptionHandlerMethodResolver(Class<?> handlerType) {
ExceptionHandlerMethodResolver resolver = this.exceptionHandlerMethodResolvers.get(handlerType);
if (resolver == null) {
resolver = new ExceptionHandlerMethodResolver(handlerType);
this.exceptionHandlerMethodResolvers.put(handlerType, resolver);
}
return resolver;
}
}