| /* Permissions.java -- a collection of permission collections |
| Copyright (C) 1998, 2001, 2002, 2004, 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package java.security; |
| |
| import java.io.Serializable; |
| import java.util.Enumeration; |
| import java.util.Hashtable; |
| import java.util.NoSuchElementException; |
| |
| /** |
| * This class is a heterogeneous collection of permissions. It is |
| * organized as a collection of <code>PermissionCollection</code>'s stored |
| * in a hashtable. Each individual <code>PermissionCollection</code> |
| * contains permissions of a single type. If a specific type of |
| * <code>Permission</code> does not provide a collection type to use |
| * via its <code>newPermissionCollection</code> method, then a default |
| * collection type which stores its permissions in a hash table will be |
| * used. |
| * |
| * @author Aaron M. Renn (arenn@urbanophile.com) |
| * @author Eric Blake (ebb9@email.byu.edu) |
| * @since 1.1 |
| */ |
| public final class Permissions extends PermissionCollection |
| implements Serializable |
| { |
| /** |
| * Compatible with JDK 1.1+. |
| */ |
| private static final long serialVersionUID = 4858622370623524688L; |
| |
| /** |
| * Holds instances of <code>AllPermission</code>. |
| * |
| * @serial the permission collection for AllPermission |
| */ |
| private PermissionCollection allPermission; |
| |
| // Package-private to avoid a trampoline. |
| /** |
| * This is the <code>Hashtable</code> that contains our collections. |
| * |
| * @serial maps Class to PermissionCollection |
| */ |
| final Hashtable perms = new Hashtable(); |
| |
| /** |
| * This method initializes a new instance of <code>Permissions</code>. |
| */ |
| public Permissions() |
| { |
| } |
| |
| /** |
| * This method adds a new <code>Permission</code> to this collection. It |
| * will be stored in a <code>PermissionCollection</code> of the appropriate |
| * type, as determined by calling <code>newPermissionCollection</code> on |
| * the specified permission (if an appropriate collection does not already |
| * exist). If this object does not specify a particular type of collection, |
| * a default collection, which stores in permissions in a hash table, will |
| * be used. |
| * |
| * @param perm the <code>Permission</code> to add |
| * @throws SecurityException if this collection is marked as read only |
| */ |
| public void add(Permission perm) |
| { |
| if (isReadOnly()) |
| throw new SecurityException("PermissionCollection is read only"); |
| if (perm instanceof AllPermission) |
| { |
| if (allPermission == null) |
| { |
| allPermission = perm.newPermissionCollection(); |
| allPermission.add(perm); |
| perms.put(perm.getClass(), allPermission); |
| } |
| } |
| else |
| { |
| PermissionCollection pc |
| = (PermissionCollection) perms.get(perm.getClass()); |
| if (pc == null) |
| { |
| pc = perm.newPermissionCollection(); |
| if (pc == null) |
| pc = new PermissionsHash(); |
| perms.put(perm.getClass(), pc); |
| } |
| pc.add(perm); |
| } |
| } |
| |
| /** |
| * This method tests whether or not the specified <code>Permission</code> |
| * is implied by this <code>PermissionCollection</code>. |
| * |
| * @param perm the <code>Permission</code> to test |
| * @return true if the specified permission is implied by this |
| */ |
| public boolean implies(Permission perm) |
| { |
| if (allPermission != null) |
| return true; |
| PermissionCollection pc |
| = (PermissionCollection) perms.get(perm.getClass()); |
| return pc == null ? false : pc.implies(perm); |
| } |
| |
| /** |
| * This method returns an <code>Enumeration</code> which contains a |
| * list of all <code>Permission</code> objects contained in this |
| * collection. |
| * |
| * @return an <code>Enumeration</code> of this collection's elements |
| */ |
| public Enumeration<Permission> elements() |
| { |
| return new Enumeration() |
| { |
| Enumeration main_enum = perms.elements(); |
| Enumeration sub_enum; |
| |
| public boolean hasMoreElements() |
| { |
| if (sub_enum == null) |
| { |
| if (main_enum == null) |
| return false; |
| if (! main_enum.hasMoreElements()) |
| { |
| main_enum = null; |
| return false; |
| } |
| PermissionCollection pc = |
| (PermissionCollection) main_enum.nextElement(); |
| sub_enum = pc.elements(); |
| } |
| if (! sub_enum.hasMoreElements()) |
| { |
| sub_enum = null; |
| return hasMoreElements(); |
| } |
| return true; |
| } |
| |
| public Object nextElement() |
| { |
| if (! hasMoreElements()) |
| throw new NoSuchElementException(); |
| return sub_enum.nextElement(); |
| } |
| }; |
| } |
| |
| /** |
| * Implements the permission collection for all permissions without one of |
| * their own, and obeys serialization of JDK. |
| * |
| * @author Eric Blake (ebb9@email.byu.edu) |
| */ |
| private static final class PermissionsHash extends PermissionCollection |
| { |
| /** |
| * Compatible with JDK 1.1+. |
| */ |
| private static final long serialVersionUID = -8491988220802933440L; |
| |
| /** |
| * Hashtable where we store permissions. |
| * |
| * @serial the stored permissions, both as key and value |
| */ |
| private final Hashtable perms = new Hashtable(); |
| |
| /** |
| * Add a permission. We don't need to check for read-only, as this |
| * collection is never exposed outside of Permissions, which has already |
| * done that check. |
| * |
| * @param perm the permission to add |
| */ |
| public void add(Permission perm) |
| { |
| perms.put(perm, perm); |
| } |
| |
| /** |
| * Returns true if perm is in the collection. |
| * |
| * @param perm the permission to check |
| * @return true if it is implied |
| */ |
| // FIXME: Should this method be synchronized? |
| public boolean implies(Permission perm) |
| { |
| Enumeration elements = elements(); |
| |
| while (elements.hasMoreElements()) |
| { |
| Permission p = (Permission)elements.nextElement(); |
| if (p.implies(perm)) |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Return the elements. |
| * |
| * @return the elements |
| */ |
| public Enumeration elements() |
| { |
| return perms.elements(); |
| } |
| } // class PermissionsHash |
| } // class Permissions |