/*
* Copyright 2002-2008 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.bind.annotation.support;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeanUtils;
import org.springframework.core.BridgeMethodResolver;
import org.springframework.core.Conventions;
import org.springframework.core.GenericTypeResolver;
import org.springframework.core.MethodParameter;
import org.springframework.core.ParameterNameDiscoverer;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.ui.ExtendedModelMap;
import org.springframework.ui.Model;
import org.springframework.util.ClassUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.validation.BindingResult;
import org.springframework.validation.Errors;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.support.DefaultSessionAttributeStore;
import org.springframework.web.bind.support.SessionAttributeStore;
import org.springframework.web.bind.support.SessionStatus;
import org.springframework.web.bind.support.SimpleSessionStatus;
import org.springframework.web.bind.support.WebArgumentResolver;
import org.springframework.web.bind.support.WebBindingInitializer;
import org.springframework.web.bind.support.WebRequestDataBinder;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.multipart.MultipartRequest;
/**
* Support class for invoking an annotated handler method.
* Operates on the introspection results of a {@link HandlerMethodResolver}
* for a specific handler type.
*
* <p>Used by {@link org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter}
* and {@link org.springframework.web.portlet.mvc.annotation.AnnotationMethodHandlerAdapter}.
*
* @author Juergen Hoeller
* @since 2.5.2
* @see #invokeHandlerMethod
*/
public class HandlerMethodInvoker {
/**
* We'll create a lot of these objects, so we don't want a new logger every time.
*/
private static final Log logger = LogFactory.getLog(HandlerMethodInvoker.class);
private final HandlerMethodResolver methodResolver;
private final WebBindingInitializer bindingInitializer;
private final SessionAttributeStore sessionAttributeStore;
private final ParameterNameDiscoverer parameterNameDiscoverer;
private final WebArgumentResolver[] customArgumentResolvers;
private final SimpleSessionStatus sessionStatus = new SimpleSessionStatus();
public HandlerMethodInvoker(HandlerMethodResolver methodResolver) {
this(methodResolver, null);
}
public HandlerMethodInvoker(HandlerMethodResolver methodResolver, WebBindingInitializer bindingInitializer) {
this(methodResolver, bindingInitializer, new DefaultSessionAttributeStore(), null);
}
public HandlerMethodInvoker(
HandlerMethodResolver methodResolver, WebBindingInitializer bindingInitializer,
SessionAttributeStore sessionAttributeStore, ParameterNameDiscoverer parameterNameDiscoverer,
WebArgumentResolver... customArgumentResolvers) {
this.methodResolver = methodResolver;
this.bindingInitializer = bindingInitializer;
this.sessionAttributeStore = sessionAttributeStore;
this.parameterNameDiscoverer = parameterNameDiscoverer;
this.customArgumentResolvers = customArgumentResolvers;
}
public final Object invokeHandlerMethod(
Method handlerMethod, Object handler, NativeWebRequest webRequest, ExtendedModelMap implicitModel)
throws Exception {
Method handlerMethodToInvoke = BridgeMethodResolver.findBridgedMethod(handlerMethod);
try {
boolean debug = logger.isDebugEnabled();
for (Method attributeMethod : this.methodResolver.getModelAttributeMethods()) {
Method attributeMethodToInvoke = BridgeMethodResolver.findBridgedMethod(attributeMethod);
Object[] args = resolveHandlerArguments(attributeMethodToInvoke, handler, webRequest, implicitModel);
if (debug) {
logger.debug("Invoking model attribute method: " + attributeMethodToInvoke);
}
Object attrValue = doInvokeMethod(attributeMethodToInvoke, handler, args);
String attrName = AnnotationUtils.findAnnotation(attributeMethodToInvoke, ModelAttribute.class).value();
if ("".equals(attrName)) {
Class resolvedType = GenericTypeResolver.resolveReturnType(attributeMethodToInvoke, handler.getClass());
attrName = Conventions.getVariableNameForReturnType(attributeMethodToInvoke, resolvedType, attrValue);
}
implicitModel.addAttribute(attrName, attrValue);
}
Object[] args = resolveHandlerArguments(handlerMethodToInvoke, handler, webRequest, implicitModel);
if (debug) {
logger.debug("Invoking request handler method: " + handlerMethodToInvoke);
}
return doInvokeMethod(handlerMethodToInvoke, handler, args);
}
catch (IllegalStateException ex) {
// Throw exception with full handler method context...
throw new HandlerMethodInvocationException(handlerMethodToInvoke, ex);
}
}
@SuppressWarnings("unchecked")
private Object[] resolveHandlerArguments(
Method handlerMethod, Object handler, NativeWebRequest webRequest, ExtendedModelMap implicitModel)
throws Exception {
Class[] paramTypes = handlerMethod.getParameterTypes();
Object[] args = new Object[paramTypes.length];
for (int i = 0; i < args.length; i++) {
MethodParameter methodParam = new MethodParameter(handlerMethod, i);
methodParam.initParameterNameDiscovery(this.parameterNameDiscoverer);
GenericTypeResolver.resolveParameterType(methodParam, handler.getClass());
String paramName = null;
boolean paramRequired = false;
String attrName = null;
Object[] paramAnns = methodParam.getParameterAnnotations();
for (int j = 0; j < paramAnns.length; j++) {
Object paramAnn = paramAnns[j];
if (RequestParam.class.isInstance(paramAnn)) {
RequestParam requestParam = (RequestParam) paramAnn;
paramName = requestParam.value();
paramRequired = requestParam.required();
break;
}
else if (ModelAttribute.class.isInstance(paramAnn)) {
ModelAttribute attr = (ModelAttribute) paramAnn;
attrName = attr.value();
}
}
if (paramName != null && attrName != null) {
throw new IllegalStateException("@RequestParam and @ModelAttribute are an exclusive choice -" +
"do not specify both on the same parameter: " + handlerMethod);
}
Class paramType = methodParam.getParameterType();
if (paramName == null && attrName == null) {
Object argValue = resolveCommonArgument(methodParam, webRequest);
if (argValue != WebArgumentResolver.UNRESOLVED) {
args[i] = argValue;
}
else {
if (Model.class.isAssignableFrom(paramType) || Map.class.isAssignableFrom(paramType)) {
args[i] = implicitModel;
}
else if (SessionStatus.class.isAssignableFrom(paramType)) {
args[i] = this.sessionStatus;
}
else if (Errors.class.isAssignableFrom(paramType)) {
throw new IllegalStateException("Errors/BindingResult argument declared " +
"without preceding model attribute. Check your handler method signature!");
}
else if (BeanUtils.isSimpleProperty(paramType)) {
paramName = "";
}
else {
attrName = "";
}
}
}
if (paramName != null) {
args[i] = resolveRequestParam(paramName, paramRequired, methodParam, webRequest, handler);
}
else if (attrName != null) {
WebDataBinder binder = resolveModelAttribute(attrName, methodParam, implicitModel, webRequest, handler);
boolean assignBindingResult = (args.length > i + 1 && Errors.class.isAssignableFrom(paramTypes[i + 1]));
if (binder.getTarget() != null) {
doBind(webRequest, binder, !assignBindingResult);
}
args[i] = binder.getTarget();
if (assignBindingResult) {
args[i + 1] = binder.getBindingResult();
i++;
}
implicitModel.putAll(binder.getBindingResult().getModel());
}
}
return args;
}
private void initBinder(Object handler, String attrName, WebDataBinder binder, NativeWebRequest webRequest)
throws Exception {
if (this.bindingInitializer != null) {
this.bindingInitializer.initBinder(binder, webRequest);
}
if (handler != null) {
Set<Method> initBinderMethods = this.methodResolver.getInitBinderMethods();
if (!initBinderMethods.isEmpty()) {
boolean debug = logger.isDebugEnabled();
for (Method initBinderMethod : initBinderMethods) {
Method methodToInvoke = BridgeMethodResolver.findBridgedMethod(initBinderMethod);
String[] targetNames = AnnotationUtils.findAnnotation(methodToInvoke, InitBinder.class).value();
if (targetNames.length == 0 || Arrays.asList(targetNames).contains(attrName)) {
Object[] initBinderArgs = resolveInitBinderArguments(handler, methodToInvoke, binder, webRequest);
if (debug) {
logger.debug("Invoking init-binder method: " + methodToInvoke);
}
Object returnValue = doInvokeMethod(methodToInvoke, handler, initBinderArgs);
if (returnValue != null) {
throw new IllegalStateException(
"InitBinder methods must not have a return value: " + methodToInvoke);
}
}
}
}
}
}
private Object[] resolveInitBinderArguments(Object handler, Method initBinderMethod,
WebDataBinder binder, NativeWebRequest webRequest) throws Exception {
Class[] initBinderParams = initBinderMethod.getParameterTypes();
Object[] initBinderArgs = new Object[initBinderParams.length];
for (int i = 0; i < initBinderArgs.length; i++) {
MethodParameter methodParam = new MethodParameter(initBinderMethod, i);
methodParam.initParameterNameDiscovery(this.parameterNameDiscoverer);
GenericTypeResolver.resolveParameterType(methodParam, handler.getClass());
String paramName = null;
boolean paramRequired = false;
Object[] paramAnns = methodParam.getParameterAnnotations();
for (int j = 0; j < paramAnns.length; j++) {
Object paramAnn = paramAnns[j];
if (RequestParam.class.isInstance(paramAnn)) {
RequestParam requestParam = (RequestParam) paramAnn;
paramName = requestParam.value();
paramRequired = requestParam.required();
break;
}
else if (ModelAttribute.class.isInstance(paramAnn)) {
throw new IllegalStateException(
"@ModelAttribute is not supported on @InitBinder methods: " + initBinderMethod);
}
}
if (paramName == null) {
Object argValue = resolveCommonArgument(methodParam, webRequest);
if (argValue != WebArgumentResolver.UNRESOLVED) {
initBinderArgs[i] = argValue;
}
else {
Class paramType = initBinderParams[i];
if (paramType.isInstance(binder)) {
initBinderArgs[i] = binder;
}
else if (BeanUtils.isSimpleProperty(paramType)) {
paramName = "";
}
else {
throw new IllegalStateException("Unsupported argument [" + paramType.getName() +
"] for @InitBinder method: " + initBinderMethod);
}
}
}
if (paramName != null) {
initBinderArgs[i] = resolveRequestParam(paramName, paramRequired, methodParam, webRequest, null);
}
}
return initBinderArgs;
}
private Object resolveRequestParam(String paramName, boolean paramRequired,
MethodParameter methodParam, NativeWebRequest webRequest, Object handlerForInitBinderCall)
throws Exception {
Class paramType = methodParam.getParameterType();
if ("".equals(paramName)) {
paramName = methodParam.getParameterName();
if (paramName == null) {
throw new IllegalStateException("No parameter specified for @RequestParam argument of type [" +
paramType.getName() + "], and no parameter name information found in class file either.");
}
}
Object paramValue = null;
if (webRequest.getNativeRequest() instanceof MultipartRequest) {
paramValue = ((MultipartRequest) webRequest.getNativeRequest()).getFile(paramName);
}
if (paramValue == null) {
String[] paramValues = webRequest.getParameterValues(paramName);
if (paramValues != null) {
paramValue = (paramValues.length == 1 ? paramValues[0] : paramValues);
}
}
if (paramValue == null) {
if (paramRequired) {
raiseMissingParameterException(paramName, paramType);
}
if (paramType.isPrimitive()) {
throw new IllegalStateException("Optional " + paramType + " parameter '" + paramName +
"' is not present but cannot be translated into a null value due to being declared as a " +
"primitive type. Consider declaring it as object wrapper for the corresponding primitive type.");
}
}
WebDataBinder binder = createBinder(webRequest, null, paramName);
initBinder(handlerForInitBinderCall, paramName, binder, webRequest);
return binder.convertIfNecessary(paramValue, paramType, methodParam);
}
private WebDataBinder resolveModelAttribute(String attrName, MethodParameter methodParam,
ExtendedModelMap implicitModel, NativeWebRequest webRequest, Object handler) throws Exception {
// Bind request parameter onto object...
String name = attrName;
if ("".equals(name)) {
name = Conventions.getVariableNameForParameter(methodParam);
}
Class paramType = methodParam.getParameterType();
Object bindObject = null;
if (implicitModel.containsKey(name)) {
bindObject = implicitModel.get(name);
}
else if (this.methodResolver.isSessionAttribute(name, paramType)) {
bindObject = this.sessionAttributeStore.retrieveAttribute(webRequest, name);
if (bindObject == null) {
raiseSessionRequiredException("Session attribute '" + name + "' required - not found in session");
}
}
else {
bindObject = BeanUtils.instantiateClass(paramType);
}
WebDataBinder binder = createBinder(webRequest, bindObject, name);
initBinder(handler, name, binder, webRequest);
return binder;
}
@SuppressWarnings("unchecked")
public final void updateModelAttributes(
Object handler, Map mavModel, ExtendedModelMap implicitModel, NativeWebRequest webRequest)
throws Exception {
if (this.methodResolver.hasSessionAttributes() && this.sessionStatus.isComplete()) {
for (String attrName : this.methodResolver.getActualSessionAttributeNames()) {
this.sessionAttributeStore.cleanupAttribute(webRequest, attrName);
}
}
// Expose model attributes as session attributes, if required.
// Expose BindingResults for all attributes, making custom editors available.
Map<String, Object> model = (mavModel != null ? mavModel : implicitModel);
for (String attrName : new HashSet<String>(model.keySet())) {
Object attrValue = model.get(attrName);
boolean isSessionAttr =
this.methodResolver.isSessionAttribute(attrName, (attrValue != null ? attrValue.getClass() : null));
if (isSessionAttr && !this.sessionStatus.isComplete()) {
this.sessionAttributeStore.storeAttribute(webRequest, attrName, attrValue);
}
if (!attrName.startsWith(BindingResult.MODEL_KEY_PREFIX) &&
(isSessionAttr || isBindingCandidate(attrValue))) {
String bindingResultKey = BindingResult.MODEL_KEY_PREFIX + attrName;
if (mavModel != null && !model.containsKey(bindingResultKey)) {
WebDataBinder binder = createBinder(webRequest, attrValue, attrName);
initBinder(handler, attrName, binder, webRequest);
mavModel.put(bindingResultKey, binder.getBindingResult());
}
}
}
}
/**
* Determine whether the given value qualifies as a "binding candidate",
* i.e. might potentially be subject to bean-style data binding later on.
*/
protected boolean isBindingCandidate(Object value) {
return (value != null && !value.getClass().isArray() && !(value instanceof Collection) &&
!(value instanceof Map) && !BeanUtils.isSimpleValueType(value.getClass()));
}
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");
}
protected void raiseMissingParameterException(String paramName, Class paramType) throws Exception {
throw new IllegalStateException("Missing parameter '" + paramName + "' of type [" + paramType.getName() + "]");
}
protected void raiseSessionRequiredException(String message) throws Exception {
throw new IllegalStateException(message);
}
protected WebDataBinder createBinder(NativeWebRequest webRequest, Object target, String objectName)
throws Exception {
return new WebRequestDataBinder(target, objectName);
}
protected void doBind(NativeWebRequest webRequest, WebDataBinder binder, boolean failOnErrors)
throws Exception {
WebRequestDataBinder requestBinder = (WebRequestDataBinder) binder;
requestBinder.bind(webRequest);
if (failOnErrors) {
requestBinder.closeNoCatch();
}
}
protected Object resolveCommonArgument(MethodParameter methodParameter, NativeWebRequest webRequest)
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);
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;
}
protected Object resolveStandardArgument(Class parameterType, NativeWebRequest webRequest)
throws Exception {
if (WebRequest.class.isAssignableFrom(parameterType)) {
return webRequest;
}
return WebArgumentResolver.UNRESOLVED;
}
}