001    /* 
002        Licensed to the Apache Software Foundation (ASF) under one
003        or more contributor license agreements.  See the NOTICE file
004        distributed with this work for additional information
005        regarding copyright ownership.  The ASF licenses this file
006        to you under the Apache License, Version 2.0 (the
007        "License"); you may not use this file except in compliance
008        with the License.  You may obtain a copy of the License at
009    
010           http://www.apache.org/licenses/LICENSE-2.0
011    
012        Unless required by applicable law or agreed to in writing,
013        software distributed under the License is distributed on an
014        "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015        KIND, either express or implied.  See the License for the
016        specific language governing permissions and limitations
017        under the License.  
018     */
019    package org.apache.wiki.auth;
020    
021    import java.security.Principal;
022    
023    /**
024     * Immutable Principal that represents a Group. GroupPrincipals are injected
025     * into a Subject's principal list at the time of authentication (login), and
026     * serve as proxies for Group objects for the purposes of making Java 2 security
027     * policy decisions. We add GroupPrincipals instead of the actual Groups because
028     * calling classes should never be able to obtain a mutable object (Group
029     * memberships can be changed by callers). Administrators who wish to grant
030     * privileges to specific wiki groups via the security policy file should always specify
031     * principals of type GroupPrincipal.
032     * @see org.apache.wiki.auth.authorize.Group
033     * @since 2.3.79
034     */
035    public final class GroupPrincipal implements Principal
036    {
037        private final String m_name;
038    
039        /**
040         * Constructs a new GroupPrincipal object with a supplied name.
041         *
042         * @param group the wiki group; cannot be <code>null</code>
043         */
044        public GroupPrincipal( String group )
045        {
046            if ( group == null )
047            {
048                throw new IllegalArgumentException( "Group parameter cannot be null." );
049            }
050            m_name = group;
051        }
052        
053        /**
054         * Returns the name of the group principal.
055         * @return the name
056         * @see java.security.Principal#getName()
057         */
058        public String getName()
059        {
060            return m_name;
061        }
062    
063        /**
064         * Two GroupPrincipals are equal if their names are equal.
065         * @param obj the object to compare
066         * @return the result of the equality test
067         * @see java.lang.Object#equals(java.lang.Object)
068         */
069        public boolean equals( Object obj )
070        {
071            if ( !( obj instanceof GroupPrincipal ) )
072            {
073                return false;
074            }
075            GroupPrincipal p = (GroupPrincipal)obj;
076            return p.m_name.equals( m_name );
077        }
078    
079        /**
080         * Returns the hashcode for this object.
081         * @return the hash code
082         * @see java.lang.Object#hashCode()
083         */
084        public int hashCode()
085        {
086            return m_name.hashCode();
087        }
088    
089        /**
090         * Returns a string representation of this object.
091         * @return the string
092         * @see java.lang.Object#toString()
093         */
094        public String toString()
095        {
096            return "[GroupPrincipal " + m_name + "]";
097        }
098    
099    }