org.springframework.web.method.support.InvocableHandlerMethod Maven / Gradle / Ivy
/*
* 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.method.support;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Arrays;
import org.springframework.core.DefaultParameterNameDiscoverer;
import org.springframework.core.MethodParameter;
import org.springframework.core.ParameterNameDiscoverer;
import org.springframework.util.ClassUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.support.SessionStatus;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.HandlerMethod;
/**
* Provides a method for invoking the handler method for a given request after resolving its
* method argument values through registered {@link HandlerMethodArgumentResolver}s.
*
* Argument resolution often requires a {@link WebDataBinder} for data binding or for type
* conversion. Use the {@link #setDataBinderFactory(WebDataBinderFactory)} property to supply
* a binder factory to pass to argument resolvers.
*
*
Use {@link #setHandlerMethodArgumentResolvers} to customize the list of argument resolvers.
*
* @author Rossen Stoyanchev
* @author Juergen Hoeller
* @since 3.1
*/
public class InvocableHandlerMethod extends HandlerMethod {
private WebDataBinderFactory dataBinderFactory;
private HandlerMethodArgumentResolverComposite argumentResolvers = new HandlerMethodArgumentResolverComposite();
private ParameterNameDiscoverer parameterNameDiscoverer = new DefaultParameterNameDiscoverer();
/**
* Create an instance from a {@code HandlerMethod}.
*/
public InvocableHandlerMethod(HandlerMethod handlerMethod) {
super(handlerMethod);
}
/**
* Create an instance from a bean instance and a method.
*/
public InvocableHandlerMethod(Object bean, Method method) {
super(bean, method);
}
/**
* Construct a new handler method with the given bean instance, method name and parameters.
* @param bean the object bean
* @param methodName the method name
* @param parameterTypes the method parameter types
* @throws NoSuchMethodException when the method cannot be found
*/
public InvocableHandlerMethod(Object bean, String methodName, Class... parameterTypes)
throws NoSuchMethodException {
super(bean, methodName, parameterTypes);
}
/**
* Set the {@link WebDataBinderFactory} to be passed to argument resolvers allowing them to create
* a {@link WebDataBinder} for data binding and type conversion purposes.
* @param dataBinderFactory the data binder factory.
*/
public void setDataBinderFactory(WebDataBinderFactory dataBinderFactory) {
this.dataBinderFactory = dataBinderFactory;
}
/**
* Set {@link HandlerMethodArgumentResolver}s to use to use for resolving method argument values.
*/
public void setHandlerMethodArgumentResolvers(HandlerMethodArgumentResolverComposite argumentResolvers) {
this.argumentResolvers = argumentResolvers;
}
/**
* Set the ParameterNameDiscoverer for resolving parameter names when needed
* (e.g. default request attribute name).
*
Default is a {@link org.springframework.core.DefaultParameterNameDiscoverer}.
*/
public void setParameterNameDiscoverer(ParameterNameDiscoverer parameterNameDiscoverer) {
this.parameterNameDiscoverer = parameterNameDiscoverer;
}
/**
* Invoke the method after resolving its argument values in the context of the given request.
*
Argument values are commonly resolved through {@link HandlerMethodArgumentResolver}s.
* The {@code providedArgs} parameter however may supply argument values to be used directly,
* i.e. without argument resolution. Examples of provided argument values include a
* {@link WebDataBinder}, a {@link SessionStatus}, or a thrown exception instance.
* Provided argument values are checked before argument resolvers.
* @param request the current request
* @param mavContainer the ModelAndViewContainer for this request
* @param providedArgs "given" arguments matched by type, not resolved
* @return the raw value returned by the invoked method
* @exception Exception raised if no suitable argument resolver can be found,
* or if the method raised an exception
*/
public Object invokeForRequest(NativeWebRequest request, ModelAndViewContainer mavContainer,
Object... providedArgs) throws Exception {
Object[] args = getMethodArgumentValues(request, mavContainer, providedArgs);
if (logger.isTraceEnabled()) {
logger.trace("Invoking '" + ClassUtils.getQualifiedMethodName(getMethod(), getBeanType()) +
"' with arguments " + Arrays.toString(args));
}
Object returnValue = doInvoke(args);
if (logger.isTraceEnabled()) {
logger.trace("Method [" + ClassUtils.getQualifiedMethodName(getMethod(), getBeanType()) +
"] returned [" + returnValue + "]");
}
return returnValue;
}
/**
* Get the method argument values for the current request.
*/
private Object[] getMethodArgumentValues(NativeWebRequest request, ModelAndViewContainer mavContainer,
Object... providedArgs) throws Exception {
MethodParameter[] parameters = getMethodParameters();
Object[] args = new Object[parameters.length];
for (int i = 0; i < parameters.length; i++) {
MethodParameter parameter = parameters[i];
parameter.initParameterNameDiscovery(this.parameterNameDiscoverer);
args[i] = resolveProvidedArgument(parameter, providedArgs);
if (args[i] != null) {
continue;
}
if (this.argumentResolvers.supportsParameter(parameter)) {
try {
args[i] = this.argumentResolvers.resolveArgument(
parameter, mavContainer, request, this.dataBinderFactory);
continue;
}
catch (Exception ex) {
if (logger.isDebugEnabled()) {
logger.debug(getArgumentResolutionErrorMessage("Failed to resolve", i), ex);
}
throw ex;
}
}
if (args[i] == null) {
throw new IllegalStateException("Could not resolve method parameter at index " +
parameter.getParameterIndex() + " in " + parameter.getMethod().toGenericString() +
": " + getArgumentResolutionErrorMessage("No suitable resolver for", i));
}
}
return args;
}
private String getArgumentResolutionErrorMessage(String text, int index) {
Class paramType = getMethodParameters()[index].getParameterType();
return text + " argument " + index + " of type '" + paramType.getName() + "'";
}
/**
* Attempt to resolve a method parameter from the list of provided argument values.
*/
private Object resolveProvidedArgument(MethodParameter parameter, Object... providedArgs) {
if (providedArgs == null) {
return null;
}
for (Object providedArg : providedArgs) {
if (parameter.getParameterType().isInstance(providedArg)) {
return providedArg;
}
}
return null;
}
/**
* Invoke the handler method with the given argument values.
*/
protected Object doInvoke(Object... args) throws Exception {
ReflectionUtils.makeAccessible(getBridgedMethod());
try {
return getBridgedMethod().invoke(getBean(), args);
}
catch (IllegalArgumentException ex) {
assertTargetBean(getBridgedMethod(), getBean(), args);
String text = (ex.getMessage() != null ? ex.getMessage() : "Illegal argument");
throw new IllegalStateException(getInvocationErrorMessage(text, args), ex);
}
catch (InvocationTargetException ex) {
// Unwrap for HandlerExceptionResolvers ...
Throwable targetException = ex.getTargetException();
if (targetException instanceof RuntimeException) {
throw (RuntimeException) targetException;
}
else if (targetException instanceof Error) {
throw (Error) targetException;
}
else if (targetException instanceof Exception) {
throw (Exception) targetException;
}
else {
String text = getInvocationErrorMessage("Failed to invoke handler method", args);
throw new IllegalStateException(text, targetException);
}
}
}
/**
* Assert that the target bean class is an instance of the class where the given
* method is declared. In some cases the actual controller instance at request-
* processing time may be a JDK dynamic proxy (lazy initialization, prototype
* beans, and others). {@code @Controller}'s that require proxying should prefer
* class-based proxy mechanisms.
*/
private void assertTargetBean(Method method, Object targetBean, Object[] args) {
Class methodDeclaringClass = method.getDeclaringClass();
Class targetBeanClass = targetBean.getClass();
if (!methodDeclaringClass.isAssignableFrom(targetBeanClass)) {
String text = "The mapped handler method class '" + methodDeclaringClass.getName() +
"' is not an instance of the actual controller bean class '" +
targetBeanClass.getName() + "'. If the controller requires proxying " +
"(e.g. due to @Transactional), please use class-based proxying.";
throw new IllegalStateException(getInvocationErrorMessage(text, args));
}
}
private String getInvocationErrorMessage(String text, Object[] resolvedArgs) {
StringBuilder sb = new StringBuilder(getDetailedErrorMessage(text));
sb.append("Resolved arguments: \n");
for (int i = 0; i < resolvedArgs.length; i++) {
sb.append("[").append(i).append("] ");
if (resolvedArgs[i] == null) {
sb.append("[null] \n");
}
else {
sb.append("[type=").append(resolvedArgs[i].getClass().getName()).append("] ");
sb.append("[value=").append(resolvedArgs[i]).append("]\n");
}
}
return sb.toString();
}
/**
* Adds HandlerMethod details such as the bean type and method signature to the message.
* @param text error message to append the HandlerMethod details to
*/
protected String getDetailedErrorMessage(String text) {
StringBuilder sb = new StringBuilder(text).append("\n");
sb.append("HandlerMethod details: \n");
sb.append("Controller [").append(getBeanType().getName()).append("]\n");
sb.append("Method [").append(getBridgedMethod().toGenericString()).append("]\n");
return sb.toString();
}
}