libjava/java/security/ProtectionDomain.java

   1 /* ProtectionDomain.java -- A security domain
   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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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;
  39
  40 /**
  41  * This class represents a group of classes, along with the permissions
  42  * they are granted.  The classes are identified by a <code>CodeSource</code>.
  43  * Thus, any class loaded from the specified <code>CodeSource</code> is
  44  * treated as part of this domain.  The set of permissions is represented
  45  * by a <code>PermissionCollection</code>.
  46  * <p>
  47  * Every class in the system will belong to one and only one
  48  * <code>ProtectionDomain</code>.
  49  *
  50  * @version 0.0
  51  *
  52  * @author Aaron M. Renn (arenn@urbanophile.com)
  53  */
  54 public class ProtectionDomain
  55 {
  56   /**
  57    * This is the <code>CodeSource</code> for this protection domain
  58    */
  59   private CodeSource code_source;
  60
  61   /**
  62    * This is the set of permissions granted to this domain
  63    */
  64   private PermissionCollection perms;
  65
  66   /**
  67    * This method initializes a new instance of <code>ProtectionDomain</code>
  68    * representing the specified <code>CodeSource</code> and permission set.
  69    * No permissions may be added to the <code>PermissionCollection</code>
  70    * and this contructor will call the <code>setReadOnly</code> method on
  71    * the specified permission set.
  72    *
  73    * @param code_source The <code>CodeSource</code> for this domain
  74    * @param perms The permission set for this domain
  75    *
  76    * @see java.security.PermissionCollection#setReadOnly()
  77    */
  78   public ProtectionDomain(CodeSource code_source, PermissionCollection perms)
  79   {
  80     this.code_source = code_source;
  81     this.perms = perms;
  82     if (perms != null)
  83       perms.setReadOnly();
  84   }
  85
  86   /**
  87      * This method returns the <code>CodeSource</code> for this domain.
  88      *
  89      * @return This domain's <code>CodeSource</code>.
  90    */
  91   public final CodeSource getCodeSource()
  92   {
  93     return code_source;
  94   }
  95
  96   /**
  97    * This method returns the set of permissions granted to this domain.
  98    *
  99    * @return The permission set for this domain
 100    */
 101   public final PermissionCollection getPermissions()
 102   {
 103     return perms;
 104   }
 105
 106   /**
 107    * This method tests whether or not the specified <code>Permission</code> is
 108    * implied by the set of permissions granted to this domain.
 109    *
 110    * @param perm The <code>Permission</code> to test.
 111    *
 112    * @return <code>true</code> if the specified <code>Permission</code> is implied for this domain, <code>false</code> otherwise.
 113    */
 114   public boolean implies(Permission perm)
 115   {
 116     PermissionCollection pc = getPermissions();
 117     if (pc == null)
 118       return (false);
 119
 120     return (pc.implies(perm));
 121   }
 122
 123   /**
 124    * This method returns a <code>String</code> representation of this
 125    * object.  It will print the <code>CodeSource</code> and
 126    * permission set associated with this domain.
 127    *
 128    * @return A <code>String</code> representation of this object.
 129    */
 130   public String toString()
 131   {
 132     String linesep = System.getProperty("line.separator");
 133     StringBuffer sb = new StringBuffer("");
 134     sb.append("ProtectionDomain (" + linesep);
 135     if (code_source == null)
 136       sb.append("CodeSource:null" + linesep);
 137     else
 138       sb.append(code_source + linesep);
 139     sb.append(perms);
 140     sb.append(linesep + ")" + linesep);
 141
 142     return sb.toString();
 143   }
 144 }