/*

  * Copyright 2007-2008 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.kns.web.listener;

 import javax.servlet.http.HttpSessionEvent;

 import javax.servlet.http.HttpSessionListener;

 import org.apache.commons.lang.StringUtils;

 import org.kuali.rice.kew.exception.WorkflowException;

 import org.kuali.rice.kns.UserSession;

 import org.kuali.rice.kns.document.Document;

 import org.kuali.rice.kns.document.authorization.PessimisticLock;

 import org.kuali.rice.kns.service.KNSServiceLocator;

 import org.kuali.rice.kns.util.GlobalVariables;

 import org.kuali.rice.kns.util.KNSConstants;

 import org.kuali.rice.kns.util.ObjectUtils;

 /**

  * This class is used to handle session timeouts where {@link PessimisticLock} objects should

  * be removed from a document 

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  *

  */

 public class KualiHttpSessionListener implements HttpSessionListener {

     /**

      *  EMPTY METHOD IMPLEMENTATION

      */

     public void sessionCreated(HttpSessionEvent se) {

         // no operation required at this time

     }

     /**

      * This method checks for the existence of a document based on session variables and deletes any locks

      * associated with the document that belong to the current user

      * 

      * @see javax.servlet.http.HttpSessionListener#sessionDestroyed(javax.servlet.http.HttpSessionEvent)

      */

     public void sessionDestroyed(HttpSessionEvent se) {

         String documentNumber = (String) se.getSession().getAttribute(KNSConstants.DOCUMENT_HTTP_SESSION_KEY);

         if (StringUtils.isNotBlank(documentNumber)) {

             try {

                 // document service needs the usersession to operate but we need the document from document service to verify it exists

                 GlobalVariables.setUserSession((UserSession)se.getSession().getAttribute(KNSConstants.USER_SESSION_KEY));

                 Document document = KNSServiceLocator.getDocumentService().getByDocumentHeaderId(documentNumber);

                 if (ObjectUtils.isNotNull(document)) {

                     KNSServiceLocator.getPessimisticLockService().releaseAllLocksForUser(document.getPessimisticLocks(), GlobalVariables.getUserSession().getPerson());

                 }

             } catch (WorkflowException e) {

                 throw new RuntimeException(e);

             } finally {

                 GlobalVariables.setUserSession(null);

             }

         }

     }

 }