Java tutorial
/* * Copyright 2004, 2005, 2006 Acegi Technology Pty Limited * * 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 * * https://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.security.util; import java.lang.reflect.Method; import org.aopalliance.intercept.MethodInvocation; import org.springframework.aop.framework.Advised; import org.springframework.aop.support.AopUtils; import org.springframework.util.Assert; /** * Static utility methods for creating <code>MethodInvocation</code>s usable within Spring * Security. * <p> * All methods of this class return a * {@link org.springframework.security.util.SimpleMethodInvocation}. * * @author Ben Alex */ public final class MethodInvocationUtils { // ~ Methods // ======================================================================================================== /** * Generates a <code>MethodInvocation</code> for specified <code>methodName</code> on * the passed object, using the <code>args</code> to locate the method. * * @param object the object that will be used to find the relevant <code>Method</code> * @param methodName the name of the method to find * @param args arguments that are required as part of the method signature (can be * empty) * * @return a <code>MethodInvocation</code>, or <code>null</code> if there was a * problem */ public static MethodInvocation create(Object object, String methodName, Object... args) { Assert.notNull(object, "Object required"); Class<?>[] classArgs = null; if (args != null) { classArgs = new Class<?>[args.length]; for (int i = 0; i < args.length; i++) { classArgs[i] = args[i].getClass(); } } // Determine the type that declares the requested method, taking into account // proxies Class<?> target = AopUtils.getTargetClass(object); if (object instanceof Advised) { Advised a = (Advised) object; if (!a.isProxyTargetClass()) { Class<?>[] possibleInterfaces = a.getProxiedInterfaces(); for (Class<?> possibleInterface : possibleInterfaces) { try { possibleInterface.getMethod(methodName, classArgs); // to get here means no exception happened target = possibleInterface; break; } catch (Exception ignored) { // try the next one } } } } return createFromClass(object, target, methodName, classArgs, args); } /** * Generates a <code>MethodInvocation</code> for the specified <code>methodName</code> * on the passed class. * * If a method with this name, taking no arguments does not exist, it will check * through the declared methods on the class, until one is found matching the supplied * name. If more than one method name matches, an <tt>IllegalArgumentException</tt> * will be raised. * * @param clazz the class of object that will be used to find the relevant * <code>Method</code> * @param methodName the name of the method to find * * @return a <code>MethodInvocation</code>, or <code>null</code> if there was a * problem */ public static MethodInvocation createFromClass(Class<?> clazz, String methodName) { MethodInvocation mi = createFromClass(null, clazz, methodName, null, null); if (mi == null) { for (Method m : clazz.getDeclaredMethods()) { if (m.getName().equals(methodName)) { if (mi != null) { throw new IllegalArgumentException( "The class " + clazz + " has more than one method named" + " '" + methodName + "'"); } mi = new SimpleMethodInvocation(null, m); } } } return mi; } /** * Generates a <code>MethodInvocation</code> for specified <code>methodName</code> on * the passed class, using the <code>args</code> to locate the method. * * @param targetObject the object being invoked * @param clazz the class of object that will be used to find the relevant * <code>Method</code> * @param methodName the name of the method to find * @param classArgs arguments that are required to locate the relevant method * signature * @param args the actual arguments that should be passed to SimpleMethodInvocation * @return a <code>MethodInvocation</code>, or <code>null</code> if there was a * problem */ public static MethodInvocation createFromClass(Object targetObject, Class<?> clazz, String methodName, Class<?>[] classArgs, Object[] args) { Assert.notNull(clazz, "Class required"); Assert.hasText(methodName, "MethodName required"); Method method; try { method = clazz.getMethod(methodName, classArgs); } catch (NoSuchMethodException e) { return null; } return new SimpleMethodInvocation(targetObject, method, args); } }