/* 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.vote;

 import org.acegisecurity.AuthorizationServiceException;

 import org.aopalliance.intercept.MethodInvocation;

 import org.aspectj.lang.JoinPoint;

 import org.aspectj.lang.reflect.CodeSignature;

 import org.springframework.util.Assert;

 /**

  * <p>Provides helper methods for writing domain object ACL voters. Is not bound to any particular ACL system.</p>

  *

  * @author Ben Alex

  * @version $Id: AbstractAclVoter.java 1754 2006-11-17 02:01:21Z benalex $

  */

 public abstract class AbstractAclVoter implements AccessDecisionVoter {

     //~ Instance fields ================================================================================================

     private Class processDomainObjectClass;

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

     protected Object getDomainObjectInstance(Object secureObject) {

         Object[] args;

         Class[] params;

         if (secureObject instanceof MethodInvocation) {

             MethodInvocation invocation = (MethodInvocation) secureObject;

             params = invocation.getMethod().getParameterTypes();

             args = invocation.getArguments();

         } else {

             JoinPoint jp = (JoinPoint) secureObject;

             params = ((CodeSignature) jp.getStaticPart().getSignature()).getParameterTypes();

             args = jp.getArgs();

         }

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

             if (processDomainObjectClass.isAssignableFrom(params[i])) {

                 return args[i];

             }

         }

         throw new AuthorizationServiceException("Secure object: " + secureObject

             + " did not provide any argument of type: " + processDomainObjectClass);

     }

     public Class getProcessDomainObjectClass() {

         return processDomainObjectClass;

     }

     public void setProcessDomainObjectClass(Class processDomainObjectClass) {

         Assert.notNull(processDomainObjectClass, "processDomainObjectClass cannot be set to null");

         this.processDomainObjectClass = processDomainObjectClass;

     }

     /**

      * This implementation supports only <code>MethodSecurityInterceptor</code>, because it queries the

      * presented <code>MethodInvocation</code>.

      *

      * @param clazz the secure object

      *

      * @return <code>true</code> if the secure object is <code>MethodInvocation</code>, <code>false</code> otherwise

      */

     public boolean supports(Class clazz) {

         if (MethodInvocation.class.isAssignableFrom(clazz)) {

             return true;

         } else if (JoinPoint.class.isAssignableFrom(clazz)) {

             return true;

         } else {

             return false;

         }

     }

 }