/* 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.concurrent;

 /**

  * Implemented by {@link org.acegisecurity.Authentication#getDetails()}

  * implementations that are capable of returning a session ID.

  *

  * <p>

  * This interface is used by {@link

  * org.acegisecurity.concurrent.SessionRegistryUtils} to extract the session

  * ID from an <code>Authentication</code> object. In turn,

  * <code>SessionRegistryUtils</code> is used by {@link

  * ConcurrentSessionControllerImpl}. If not using this latter implementation,

  * you do not need the <code>Authentication.getDetails()</code> object to

  * implement <code>SessionIdentifierAware</code>.

  * </p>

  *

  * @author Ben Alex

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

  */

 public interface SessionIdentifierAware {

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

     /**

      * Obtains the session ID.

      *

      * @return the session ID, or <code>null</code> if not known.

      */

     String getSessionId();

 }