/* 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

  *

  *     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.acegisecurity.util;

 import org.aopalliance.intercept.MethodInvocation;

 import org.springframework.util.Assert;

 import java.lang.reflect.Method;

 import java.util.ArrayList;

 import java.util.List;

 /**

  * Static utility methods for creating <code>MethodInvocation</code>s usable within Acegi Security.<p>All methods

  * of this class return a {@link org.acegisecurity.util.SimpleMethodInvocation}.</p>

  *

  * @author Ben Alex

  * @version $Id: MethodInvocationUtils.java 1784 2007-02-24 21:00:24Z luke_t $

  */

 public final class MethodInvocationUtils {

     //~ Constructors ===================================================================================================

     private MethodInvocationUtils() {

     }

     //~ Methods ========================================================================================================

     /**

      * Generates a <code>MethodInvocation</code> for specified <code>methodName</code> on the passed object.

      *

      * @param object the 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 create(Object object, String methodName) {

         return create(object, methodName, null);

     }

     /**

      * 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

      *

      * @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) {

             List list = new ArrayList();

             for (int i = 0; i < args.length; i++) {

                 list.add(args[i].getClass());

             }

             classArgs = (Class[]) list.toArray(new Class[] {});

         }

         return createFromClass(object.getClass(), methodName, classArgs, args);

     }

     /**

      * Generates a <code>MethodInvocation</code> for specified <code>methodName</code> on the passed class.

      *

      * @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) {

         return createFromClass(clazz, methodName, null, null);

     }

     /**

      * Generates a <code>MethodInvocation</code> for specified <code>methodName</code> on the passed class,

      * using the <code>args</code> to locate the method.

      *

      * @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(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 (Exception e) {

             return null;

         }

         return new SimpleMethodInvocation(method, args);

     }

 }