/* * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.security.acl; import java.util.Enumeration; import java.security.Principal; /** * This interface is used to represent a group of principals. (A principal * represents an entity such as an individual user or a company).
* * Note that Group extends Principal. Thus, either a Principal or a Group can * be passed as an argument to methods containing a Principal parameter. For * example, you can add either a Principal or a Group to a Group object by * calling the object's {@code addMember} method, passing it the * Principal or Group. * * @author Satish Dharmaraj */ public interface Group extends Principal { /** * Adds the specified member to the group. * * @param user the principal to add to this group. * * @return true if the member was successfully added, * false if the principal was already a member. */ public boolean addMember(Principal user); /** * Removes the specified member from the group. * * @param user the principal to remove from this group. * * @return true if the principal was removed, or * false if the principal was not a member. */ public boolean removeMember(Principal user); /** * Returns true if the passed principal is a member of the group. * This method does a recursive search, so if a principal belongs to a * group which is a member of this group, true is returned. * * @param member the principal whose membership is to be checked. * * @return true if the principal is a member of this group, * false otherwise. */ public boolean isMember(Principal member); /** * Returns an enumeration of the members in the group. * The returned objects can be instances of either Principal * or Group (which is a subclass of Principal). * * @return an enumeration of the group members. */ public Enumeration extends Principal> members(); }