/*
* Copyright 2002-2012 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.portlet.mvc.annotation;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.security.Principal;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import javax.portlet.ClientDataRequest;
import javax.portlet.Event;
import javax.portlet.EventRequest;
import javax.portlet.MimeResponse;
import javax.portlet.PortalContext;
import javax.portlet.PortletMode;
import javax.portlet.PortletPreferences;
import javax.portlet.PortletRequest;
import javax.portlet.PortletResponse;
import javax.portlet.PortletSession;
import javax.portlet.WindowState;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpSession;
import org.springframework.core.ExceptionDepthComparator;
import org.springframework.core.GenericTypeResolver;
import org.springframework.core.MethodParameter;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.ui.Model;
import org.springframework.util.ClassUtils;
import org.springframework.util.ObjectUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.support.WebArgumentResolver;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.portlet.ModelAndView;
import org.springframework.web.portlet.context.PortletWebRequest;
import org.springframework.web.portlet.handler.AbstractHandlerExceptionResolver;
import org.springframework.web.servlet.View;
/**
* Implementation of the {@link org.springframework.web.portlet.HandlerExceptionResolver} interface that handles
* exceptions through the {@link ExceptionHandler} annotation.
*
* <p>This exception resolver is enabled by default in the {@link org.springframework.web.portlet.DispatcherPortlet}.
*
* @author Arjen Poutsma
* @author Juergen Hoeller
* @since 3.0
*/
public class AnnotationMethodHandlerExceptionResolver extends AbstractHandlerExceptionResolver {
// dummy method placeholder
private static final Method NO_METHOD_FOUND =
ClassUtils.getMethodIfAvailable(System.class, "currentTimeMillis", (Class<?>[]) null);
private final Map<Class<?>, Map<Class<? extends Throwable>, Method>> exceptionHandlerCache =
new ConcurrentHashMap<Class<?>, Map<Class<? extends Throwable>, Method>>(64);
private WebArgumentResolver[] customArgumentResolvers;
/**
* Set a custom ArgumentResolvers to use for special method parameter types.
* <p>Such a custom ArgumentResolver will kick in first, having a chance to resolve
* an argument value before the standard argument handling kicks in.
*/
public void setCustomArgumentResolver(WebArgumentResolver argumentResolver) {
this.customArgumentResolvers = new WebArgumentResolver[]{argumentResolver};
}
/**
* Set one or more custom ArgumentResolvers to use for special method parameter types.
* <p>Any such custom ArgumentResolver will kick in first, having a chance to resolve
* an argument value before the standard argument handling kicks in.
*/
public void setCustomArgumentResolvers(WebArgumentResolver[] argumentResolvers) {
this.customArgumentResolvers = argumentResolvers;
}
@Override
protected ModelAndView doResolveException(
PortletRequest request, MimeResponse response, Object handler, Exception ex) {
if (handler != null) {
Method handlerMethod = findBestExceptionHandlerMethod(handler, ex);
if (handlerMethod != null) {
NativeWebRequest webRequest = new PortletWebRequest(request, response);
try {
Object[] args = resolveHandlerArguments(handlerMethod, handler, webRequest, ex);
if (logger.isDebugEnabled()) {
logger.debug("Invoking request handler method: " + handlerMethod);
}
Object retVal = doInvokeMethod(handlerMethod, handler, args);
return getModelAndView(retVal);
}
catch (Exception invocationEx) {
logger.error("Invoking request method resulted in exception : " + handlerMethod, invocationEx);
}
}
}
return null;
}
/**
* Finds the handler method that matches the thrown exception best.
* @param handler the handler object
* @param thrownException the exception to be handled
* @return the best matching method; or {@code null} if none is found
*/
private Method findBestExceptionHandlerMethod(Object handler, final Exception thrownException) {
final Class<?> handlerType = handler.getClass();
final Class<? extends Throwable> thrownExceptionType = thrownException.getClass();
Method handlerMethod;
Map<Class<? extends Throwable>, Method> handlers = this.exceptionHandlerCache.get(handlerType);
if (handlers != null) {
handlerMethod = handlers.get(thrownExceptionType);
if (handlerMethod != null) {
return (handlerMethod == NO_METHOD_FOUND ? null : handlerMethod);
}
}
else {
handlers = new ConcurrentHashMap<Class<? extends Throwable>, Method>(16);
this.exceptionHandlerCache.put(handlerType, handlers);
}
final Map<Class<? extends Throwable>, Method> matchedHandlers = new HashMap<Class<? extends Throwable>, Method>();
ReflectionUtils.doWithMethods(handlerType, new ReflectionUtils.MethodCallback() {
@Override
public void doWith(Method method) {
method = ClassUtils.getMostSpecificMethod(method, handlerType);
List<Class<? extends Throwable>> handledExceptions = getHandledExceptions(method);
for (Class<? extends Throwable> handledException : handledExceptions) {
if (handledException.isAssignableFrom(thrownExceptionType)) {
if (!matchedHandlers.containsKey(handledException)) {
matchedHandlers.put(handledException, method);
}
else {
Method oldMappedMethod = matchedHandlers.get(handledException);
if (!oldMappedMethod.equals(method)) {
throw new IllegalStateException(
"Ambiguous exception handler mapped for " + handledException + "]: {" +
oldMappedMethod + ", " + method + "}.");
}
}
}
}
}
});
handlerMethod = getBestMatchingMethod(matchedHandlers, thrownException);
handlers.put(thrownExceptionType, (handlerMethod == null ? NO_METHOD_FOUND : handlerMethod));
return handlerMethod;
}
/**
* Returns all the exception classes handled by the given method.
* <p>Default implementation looks for exceptions in the {@linkplain ExceptionHandler#value() annotation},
* or - if that annotation element is empty - any exceptions listed in the method parameters if the
* method is annotated with {@code @ExceptionHandler}.
* @param method the method
* @return the handled exceptions
*/
@SuppressWarnings("unchecked")
protected List<Class<? extends Throwable>> getHandledExceptions(Method method) {
List<Class<? extends Throwable>> result = new ArrayList<Class<? extends Throwable>>();
ExceptionHandler exceptionHandler = AnnotationUtils.findAnnotation(method, ExceptionHandler.class);
if (exceptionHandler != null) {
if (!ObjectUtils.isEmpty(exceptionHandler.value())) {
result.addAll(Arrays.asList(exceptionHandler.value()));
}
else {
for (Class<?> param : method.getParameterTypes()) {
if (Throwable.class.isAssignableFrom(param)) {
result.add((Class<? extends Throwable>) param);
}
}
}
}
return result;
}
/**
* Uses the {@link ExceptionDepthComparator} to find the best matching method.
* @return the best matching method or {@code null}.
*/
private Method getBestMatchingMethod(
Map<Class<? extends Throwable>, Method> resolverMethods, Exception thrownException) {
if (resolverMethods.isEmpty()) {
return null;
}
Class<? extends Throwable> closestMatch =
ExceptionDepthComparator.findClosestMatch(resolverMethods.keySet(), thrownException);
Method method = resolverMethods.get(closestMatch);
return (method == null || NO_METHOD_FOUND == method ? null : method);
}
/**
* Resolves the arguments for the given method. Delegates to {@link #resolveCommonArgument}.
*/
private Object[] resolveHandlerArguments(Method handlerMethod, Object handler,
NativeWebRequest webRequest, Exception thrownException) throws Exception {
Class<?>[] paramTypes = handlerMethod.getParameterTypes();
Object[] args = new Object[paramTypes.length];
Class<?> handlerType = handler.getClass();
for (int i = 0; i < args.length; i++) {
MethodParameter methodParam = new MethodParameter(handlerMethod, i);
GenericTypeResolver.resolveParameterType(methodParam, handlerType);
Class<?> paramType = methodParam.getParameterType();
Object argValue = resolveCommonArgument(methodParam, webRequest, thrownException);
if (argValue != WebArgumentResolver.UNRESOLVED) {
args[i] = argValue;
}
else {
throw new IllegalStateException("Unsupported argument [" + paramType.getName() +
"] for @ExceptionHandler method: " + handlerMethod);
}
}
return args;
}
/**
* Resolves common method arguments. Delegates to registered
* {@link #setCustomArgumentResolver argumentResolvers} first,
* then checking {@link #resolveStandardArgument}.
* @param methodParameter the method parameter
* @param webRequest the request
* @param thrownException the exception thrown
* @return the argument value, or {@link org.springframework.web.bind.support.WebArgumentResolver#UNRESOLVED}
*/
protected Object resolveCommonArgument(MethodParameter methodParameter, NativeWebRequest webRequest,
Exception thrownException) throws Exception {
// Invoke custom argument resolvers if present...
if (this.customArgumentResolvers != null) {
for (WebArgumentResolver argumentResolver : this.customArgumentResolvers) {
Object value = argumentResolver.resolveArgument(methodParameter, webRequest);
if (value != WebArgumentResolver.UNRESOLVED) {
return value;
}
}
}
// Resolution of standard parameter types...
Class<?> paramType = methodParameter.getParameterType();
Object value = resolveStandardArgument(paramType, webRequest, thrownException);
if (value != WebArgumentResolver.UNRESOLVED && !ClassUtils.isAssignableValue(paramType, value)) {
throw new IllegalStateException("Standard argument type [" + paramType.getName() +
"] resolved to incompatible value of type [" + (value != null ? value.getClass() : null) +
"]. Consider declaring the argument type in a less specific fashion.");
}
return value;
}
/**
* Resolves standard method arguments. The default implementation handles {@link NativeWebRequest},
* {@link ServletRequest}, {@link ServletResponse}, {@link HttpSession}, {@link Principal},
* {@link Locale}, request {@link InputStream}, request {@link Reader}, response {@link OutputStream},
* response {@link Writer}, and the given {@code thrownException}.
* @param parameterType the method parameter type
* @param webRequest the request
* @param thrownException the exception thrown
* @return the argument value, or {@link org.springframework.web.bind.support.WebArgumentResolver#UNRESOLVED}
*/
protected Object resolveStandardArgument(Class<?> parameterType, NativeWebRequest webRequest,
Exception thrownException) throws Exception {
if (parameterType.isInstance(thrownException)) {
return thrownException;
}
else if (WebRequest.class.isAssignableFrom(parameterType)) {
return webRequest;
}
PortletRequest request = webRequest.getNativeRequest(PortletRequest.class);
PortletResponse response = webRequest.getNativeResponse(PortletResponse.class);
if (PortletRequest.class.isAssignableFrom(parameterType)) {
return request;
}
else if (PortletResponse.class.isAssignableFrom(parameterType)) {
return response;
}
else if (PortletSession.class.isAssignableFrom(parameterType)) {
return request.getPortletSession();
}
else if (PortletPreferences.class.isAssignableFrom(parameterType)) {
return request.getPreferences();
}
else if (PortletMode.class.isAssignableFrom(parameterType)) {
return request.getPortletMode();
}
else if (WindowState.class.isAssignableFrom(parameterType)) {
return request.getWindowState();
}
else if (PortalContext.class.isAssignableFrom(parameterType)) {
return request.getPortalContext();
}
else if (Principal.class.isAssignableFrom(parameterType)) {
return request.getUserPrincipal();
}
else if (Locale.class.equals(parameterType)) {
return request.getLocale();
}
else if (InputStream.class.isAssignableFrom(parameterType)) {
if (!(request instanceof ClientDataRequest)) {
throw new IllegalStateException("InputStream can only get obtained for Action/ResourceRequest");
}
return ((ClientDataRequest) request).getPortletInputStream();
}
else if (Reader.class.isAssignableFrom(parameterType)) {
if (!(request instanceof ClientDataRequest)) {
throw new IllegalStateException("Reader can only get obtained for Action/ResourceRequest");
}
return ((ClientDataRequest) request).getReader();
}
else if (OutputStream.class.isAssignableFrom(parameterType)) {
if (!(response instanceof MimeResponse)) {
throw new IllegalStateException("OutputStream can only get obtained for Render/ResourceResponse");
}
return ((MimeResponse) response).getPortletOutputStream();
}
else if (Writer.class.isAssignableFrom(parameterType)) {
if (!(response instanceof MimeResponse)) {
throw new IllegalStateException("Writer can only get obtained for Render/ResourceResponse");
}
return ((MimeResponse) response).getWriter();
}
else if (Event.class.equals(parameterType)) {
if (!(request instanceof EventRequest)) {
throw new IllegalStateException("Event can only get obtained from EventRequest");
}
return ((EventRequest) request).getEvent();
}
else {
return WebArgumentResolver.UNRESOLVED;
}
}
private Object doInvokeMethod(Method method, Object target, Object[] args) throws Exception {
ReflectionUtils.makeAccessible(method);
try {
return method.invoke(target, args);
}
catch (InvocationTargetException ex) {
ReflectionUtils.rethrowException(ex.getTargetException());
}
throw new IllegalStateException("Should never get here");
}
@SuppressWarnings("unchecked")
private ModelAndView getModelAndView(Object returnValue) {
if (returnValue instanceof ModelAndView) {
return (ModelAndView) returnValue;
}
else if (returnValue instanceof Model) {
return new ModelAndView().addAllObjects(((Model) returnValue).asMap());
}
else if (returnValue instanceof Map) {
return new ModelAndView().addAllObjects((Map<String, Object>) returnValue);
}
else if (returnValue instanceof View) {
return new ModelAndView(returnValue);
}
else if (returnValue instanceof String) {
return new ModelAndView((String) returnValue);
}
else if (returnValue == null) {
return new ModelAndView();
}
else {
throw new IllegalArgumentException("Invalid handler method return value: " + returnValue);
}
}
}