Source for java.security.acl.AclEntry

   1: /* AclEntry.java -- An entry in an ACL list.
   2:    Copyright (C) 1998 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: package java.security.acl;
  39: 
  40: import java.security.Principal;
  41: import java.util.Enumeration;
  42: 
  43: /**
  44:  * This interface models an entry in an access control list (ACL).  Java
  45:  * ACL's consist of a list of entries, where each consists of a 
  46:  * <code>Principal</code> and a list of <code>Permission</code>'s which
  47:  * have been granted to that <code>Principal</code>.  An ACL can also
  48:  * be <em>negative</em>, which indicates that the list of 
  49:  * <code>Permission</code>'s is a list of permissions that are <em>not</em>
  50:  * granted to the <code>Principal</code>.  A <code>Principal</code> can
  51:  * have at most one regular (or positive) ACL entry and one negative
  52:  * ACL entry.
  53:  *
  54:  * @version 0.0
  55:  *
  56:  * @author Aaron M. Renn (arenn@urbanophile.com)
  57:  */
  58: public interface AclEntry extends Cloneable
  59: {
  60:  /**
  61:    * This method returns the <code>Principal</code> associated with this
  62:    * ACL entry.
  63:    *
  64:    * @return The <code>Principal</code> for this ACL entry
  65:    */
  66:   Principal getPrincipal();
  67: 
  68:   /**
  69:    * This method sets ths <code>Principal</code> associated with this
  70:    * ACL entry.  This operation will only succeed if there is not already
  71:    * a <code>Principal</code> assigned.
  72:    *
  73:    * @param user The <code>Principal</code> for this ACL entry
  74:    *
  75:    * @return <code>true</code> if the <code>Principal</code> was successfully set or <code>false</code> if this entry already has a <code>Principal</code>.
  76:    */
  77:   boolean setPrincipal(Principal user);
  78: 
  79:   /**
  80:    * This method sets this ACL entry to be a <em>negative</em> entry, indicating
  81:    * that it contains a list of permissions that are <em>not</em> granted
  82:    * to the entry's <code>Principal</code>.  Note that there is no way to
  83:    * undo this operation.
  84:    */
  85:   void setNegativePermissions();
  86: 
  87:   /**
  88:    * This method tests whether or not this ACL entry is a negative entry or not.
  89:    *
  90:    * @return <code>true</code> if this ACL entry is negative, <code>false</code> otherwise
  91:    */
  92:   boolean isNegative();
  93: 
  94:   /**
  95:    * This method adds the specified permission to this ACL entry.
  96:    *
  97:    * @param permission The <code>Permission</code> to add
  98:    *
  99:    * @return <code>true</code> if the permission was added or <code>false</code> if it was already set for this entry
 100:    */
 101:   boolean addPermission(Permission permission);
 102: 
 103:   /**
 104:    * This method deletes the specified permission to this ACL entry.
 105:    *
 106:    * @param perm The <code>Permission</code> to delete from this ACL entry.
 107:    *
 108:    * @return <code>true</code> if the permission was successfully deleted or <code>false</code> if the permission was not part of this ACL to begin with
 109:    */
 110:   boolean removePermission(Permission perm);
 111: 
 112:   /**
 113:    * This method tests whether or not the specified permission is associated
 114:    * with this ACL entry.
 115:    *
 116:    * @param permission The <code>Permission</code> to test
 117:    *
 118:    * @return <code>true</code> if this permission is associated with this entry or <code>false</code> otherwise
 119:    */
 120:   boolean checkPermission(Permission permission);
 121: 
 122:   /**
 123:    * This method returns a list of all <code>Permission</code> objects
 124:    * associated with this ACL entry as an <code>Enumeration</code>.
 125:    *
 126:    * @return A list of permissions for this ACL entry
 127:    */
 128:   Enumeration<Permission> permissions();
 129: 
 130:   /**
 131:    * This method returns this object as a <code>String</code>.
 132:    *
 133:    * @return A <code>String</code> representation of this object
 134:    */
 135:   String toString();
 136: 
 137:   /**
 138:    * This method returns a clone of this ACL entry
 139:    *
 140:    * @return A clone of this ACL entry
 141:    */
 142:   Object clone();
 143: }