/* 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.context.rmi;

 import org.acegisecurity.context.SecurityContext;

 import org.acegisecurity.context.SecurityContextHolder;

 import org.aopalliance.intercept.MethodInvocation;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.springframework.remoting.support.RemoteInvocation;

 import java.lang.reflect.InvocationTargetException;

 /**

  * The actual <code>RemoteInvocation</code> that is passed from the client to the server, which contains the

  * contents of {@link SecurityContextHolder}, being a {@link SecurityContext} object.<p>When constructed on the

  * client via {@link org.acegisecurity.context.rmi.ContextPropagatingRemoteInvocationFactory}, the contents of the

  * <code>SecurityContext</code> are stored inside the object. The object is then passed to the server that is

  * processing the remote invocation. Upon the server invoking the remote invocation, it will retrieve the passed

  * contents of the <code>SecurityContextHolder</code> and set them to the server-side

  * <code>SecurityContextHolder</code> whilst the target object is invoked. When the target invocation has been

  * completed, the server-side <code>SecurityContextHolder</code> will be reset to a new instance of

  * <code>SecurityContextImpl</code>.</p>

  *

  * @author James Monaghan

  * @author Ben Alex

  * @version $Id: ContextPropagatingRemoteInvocation.java 1496 2006-05-23 13:38:33Z benalex $

  */

 public class ContextPropagatingRemoteInvocation extends RemoteInvocation {

     //~ Static fields/initializers =====================================================================================

     private static final Log logger = LogFactory.getLog(ContextPropagatingRemoteInvocation.class);

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

     private SecurityContext securityContext;

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

 /**

      * Constructs the object, storing the value of the client-side

      * <code>SecurityContextHolder</code> inside the object.

      *

      * @param methodInvocation the method to invoke

      */

     public ContextPropagatingRemoteInvocation(MethodInvocation methodInvocation) {

         super(methodInvocation);

         securityContext = SecurityContextHolder.getContext();

         if (logger.isDebugEnabled()) {

             logger.debug("RemoteInvocation now has SecurityContext: " + securityContext);

         }

     }

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

     /**

      * Invoked on the server-side as described in the class JavaDocs.<p>Invocations will always have their

      * {@link org.acegisecurity.Authentication#setAuthenticated(boolean)} set to <code>false</code>, which is

      * guaranteed to always be accepted by <code>Authentication</code> implementations. This ensures that even

      * remotely authenticated <code>Authentication</code>s will be untrusted by the server-side, which is an

      * appropriate security measure.</p>

      *

      * @param targetObject the target object to apply the invocation to

      *

      * @return the invocation result

      *

      * @throws NoSuchMethodException if the method name could not be resolved

      * @throws IllegalAccessException if the method could not be accessed

      * @throws InvocationTargetException if the method invocation resulted in an exception

      */

     public Object invoke(Object targetObject)

         throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {

         SecurityContextHolder.setContext(securityContext);

         if ((SecurityContextHolder.getContext() != null)

             && (SecurityContextHolder.getContext().getAuthentication() != null)) {

             SecurityContextHolder.getContext().getAuthentication().setAuthenticated(false);

         }

         if (logger.isDebugEnabled()) {

             logger.debug("Set SecurityContextHolder to contain: " + securityContext);

         }

         try {

             return super.invoke(targetObject);

         } finally {

             SecurityContextHolder.clearContext();

             if (logger.isDebugEnabled()) {

                 logger.debug("Set SecurityContext to new instance of SecurityContextImpl");

             }

         }

     }

 }