001    /*
002     * CDDL HEADER START
003     *
004     * The contents of this file are subject to the terms of the
005     * Common Development and Distribution License, Version 1.0 only
006     * (the "License").  You may not use this file except in compliance
007     * with the License.
008     *
009     * You can obtain a copy of the license at
010     * trunk/opends/resource/legal-notices/OpenDS.LICENSE
011     * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
012     * See the License for the specific language governing permissions
013     * and limitations under the License.
014     *
015     * When distributing Covered Code, include this CDDL HEADER in each
016     * file and include the License file at
017     * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
018     * add the following below this CDDL HEADER, with the fields enclosed
019     * by brackets "[]" replaced with your own identifying information:
020     *      Portions Copyright [yyyy] [name of copyright owner]
021     *
022     * CDDL HEADER END
023     *
024     *
025     *      Copyright 2006-2008 Sun Microsystems, Inc.
026     */
027    package org.opends.server.types;
028    
029    
030    /**
031     * This class defines a mechanism that may be used to iterate over the
032     * members of a group.  It uses an interface that is similar to that
033     * of {@code java.util.Iterator}, but is specific to group membership
034     * and that provides the ability to throw an exception when attempting
035     * to retrieve the next member (e.g., if the group contains a
036     * malformed DN or references a member that doesn't exist).
037     */
038    @org.opends.server.types.PublicAPI(
039         stability=org.opends.server.types.StabilityLevel.VOLATILE,
040         mayInstantiate=false,
041         mayExtend=true,
042         mayInvoke=true)
043    public abstract class MemberList
044    {
045      /**
046       * Indicates whether the group contains any more members.
047       *
048       * @return  {@code true} if the group has at least one more member,
049       *          or {@code false} if not.
050       */
051      public abstract boolean hasMoreMembers();
052    
053    
054    
055      /**
056       * Retrieves the DN of the next group member.
057       *
058       * @return  The DN of the next group member, or {@code null} if
059       *          there are no more members.
060       *
061       * @throws  MembershipException  If a problem occurs while
062       *                               attempting to retrieve the next
063       *                               member DN.
064       */
065      public DN nextMemberDN()
066             throws MembershipException
067      {
068        Entry e = nextMemberEntry();
069        if (e == null)
070        {
071          return null;
072        }
073        else
074        {
075          return e.getDN();
076        }
077      }
078    
079    
080    
081      /**
082       * Retrieves the entry for the next group member.
083       *
084       * @return  The entry for the next group member, or {@code null} if
085       *          there are no more members.
086       *
087       * @throws  MembershipException  If a problem occurs while
088       *                               attempting to retrieve the next
089       *                               entry.
090       */
091      public abstract Entry nextMemberEntry()
092             throws MembershipException;
093    
094    
095    
096      /**
097       * Indicates that this member list is no longer required and that
098       * the server may clean up any resources that may have been used in
099       * the course of processing.  This method must be called if the
100       * caller wishes to stop iterating across the member list before the
101       * end has been reached, although it will not be necessary if the
102       * call to {@code hasMoreMembers} returns {@code false}.
103       */
104      public abstract void close();
105    }
106