001    /* Owner.java -- ACL owner
002       Copyright (C) 1998 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package java.security.acl;
039    
040    import java.security.Principal;
041    
042    /**
043     * This interface provides a mechanism for maintaining a list of owners
044     * of an access control list (ACL).  Since a <code>Principal</code> must
045     * be an owner in order to modify the owner list, a mechanism must be
046     * provided to specify the initial owner of the ACL.  The proper way to do
047     * this is for the implementing class to specify the initial owner in
048     * the contructor for that class.
049     *
050     * @version 0.0
051     *
052     * @author Aaron M. Renn (arenn@urbanophile.com)
053     */
054    public interface Owner
055    {
056      /**
057       * This method adds an owner to the access control list (ACL).  Only a
058       * <code>Principal</code> who is already an owner can perform this operation.
059       *
060       * @param caller The <code>Principal</code> who is requesting that an owner be added
061       * @param owner The <code>Principal</code> to add as a new owner
062       *
063       * @param <code>true</code> if the new owner was successfully added or <code>false</code> if the specified new owner is already an owner
064       *
065       * @exception NotOwnerException If the caller is not already an owner of this ACL
066       */
067      boolean addOwner(Principal caller, Principal owner) 
068        throws NotOwnerException;
069    
070      /**
071       * This method delets an owner from the access control list (ACL).  Only a
072       * <code>Principal</code> who is an owner can perform this operation.  An
073       * owner can delete itself from the list.  If there is only one
074       * owner remaining on this list, any attempt to delete it will throw an
075       * exception.
076       *
077       * @param caller The <code>Principal</code> who is requesting that an owner be deleted
078       * @param owner The <code>Principal</code> to delete as an owner
079       *
080       * @param <code>true</code> if the new owner was successfully deleted or <code>false</code> if the specified owner is not currently an owner
081       *
082       * @exception NotOwnerException If the caller is not already an owner of this ACL
083       * @exception LastOwnerException If completing the operation would delete the last ACL owner
084       */
085      boolean deleteOwner(Principal caller, Principal owner) 
086        throws NotOwnerException, LastOwnerException;
087    
088      /**
089       * This method tests whether or not a given <code>Principal</code> is an
090       * owner of this access control list (ACL).
091       *
092       * @return <code>true</code> if the <code>Principal</code> is an owner, <code>false</code> otherwise
093       */
094      boolean isOwner(Principal owner);
095    }