/* 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.acls.sid;

 /**

  * A security identity recognised by the ACL system.

  *

  * <p>

  * This interface provides indirection between actual security objects (eg

  * principals, roles, groups etc) and what is stored inside an

  * <code>Acl</code>. This is because an <code>Acl</code> will not store an

  * entire security object, but only an abstraction of it. This interface

  * therefore provides a simple way to compare these abstracted security

  * identities with other security identities and actual security objects.

  * </p>

  *

  * @author Ben Alex

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

  */

 public interface Sid {

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

     /**

      * Refer to the <code>java.lang.Object</code> documentation for the interface contract.

      *

      * @param obj to be compared

      *

      * @return <code>true</code> if the objects are equal, <code>false</code> otherwise

      */

     boolean equals(Object obj);

     /**

      * Refer to the <code>java.lang.Object</code> documentation for the interface contract.

      *

      * @return a hash code representation of this object

      */

     int hashCode();

 }