| /* PropertyPermissionCollection.java -- a collection of PropertyPermissions |
| Copyright (C) 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., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 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.util; |
| |
| import java.security.Permission; |
| import java.security.PermissionCollection; |
| |
| /** |
| * This class provides the implementation for |
| * <code>PropertyPermission.newPermissionCollection()</code>. It only accepts |
| * PropertyPermissions, and correctly implements <code>implies</code>. It |
| * is synchronized, as specified in the superclass. |
| * |
| * @author Eric Blake (ebb9@email.byu.edu) |
| * @status an undocumented class, but this matches Sun's serialization |
| */ |
| class PropertyPermissionCollection extends PermissionCollection |
| { |
| /** |
| * Compatible with JDK 1.4. |
| */ |
| private static final long serialVersionUID = 7015263904581634791L; |
| |
| /** |
| * The permissions. |
| * |
| * @serial the table of permissions in the collection |
| */ |
| private final Hashtable permissions = new Hashtable(); |
| |
| /** |
| * A flag to detect if "*" is in the collection. |
| * |
| * @serial true if "*" is in the collection |
| */ |
| private boolean all_allowed; |
| |
| /** |
| * Adds a PropertyPermission to this collection. |
| * |
| * @param permission the permission to add |
| * @throws IllegalArgumentException if permission is not a PropertyPermission |
| * @throws SecurityException if collection is read-only |
| */ |
| public void add(Permission permission) |
| { |
| if (isReadOnly()) |
| throw new SecurityException("readonly"); |
| if (! (permission instanceof PropertyPermission)) |
| throw new IllegalArgumentException(); |
| PropertyPermission pp = (PropertyPermission) permission; |
| String name = pp.getName(); |
| if (name.equals("*")) |
| all_allowed = true; |
| PropertyPermission old = (PropertyPermission) permissions.get(name); |
| if (old != null) |
| { |
| if ((pp.actions | old.actions) == old.actions) |
| pp = old; // Old implies pp. |
| else if ((pp.actions | old.actions) != pp.actions) |
| // Here pp doesn't imply old; the only case left is both actions. |
| pp = new PropertyPermission(name, "read,write"); |
| } |
| permissions.put(name, pp); |
| } |
| |
| /** |
| * Returns true if this collection implies the given permission. This even |
| * returns true for this case: |
| * |
| * <pre> |
| * collection.add(new PropertyPermission("a.*", "read")); |
| * collection.add(new PropertyPermission("a.b.*", "write")); |
| * collection.implies(new PropertyPermission("a.b.c", "read,write")); |
| * </pre> |
| * |
| * @param permission the permission to check |
| * @return true if it is implied by this |
| */ |
| public boolean implies(Permission permission) |
| { |
| if (! (permission instanceof PropertyPermission)) |
| return false; |
| PropertyPermission toImply = (PropertyPermission) permission; |
| int actions = toImply.actions; |
| |
| if (all_allowed) |
| { |
| int all_actions = ((PropertyPermission) permissions.get("*")).actions; |
| actions &= ~all_actions; |
| if (actions == 0) |
| return true; |
| } |
| |
| String name = toImply.getName(); |
| if (name.equals("*")) |
| return false; |
| |
| int prefixLength = name.length(); |
| if (name.endsWith("*")) |
| prefixLength -= 2; |
| |
| while (true) |
| { |
| PropertyPermission forName = |
| (PropertyPermission) permissions.get(name); |
| if (forName != null) |
| { |
| actions &= ~forName.actions; |
| if (actions == 0) |
| return true; |
| } |
| |
| prefixLength = name.lastIndexOf('.', prefixLength - 1); |
| if (prefixLength < 0) |
| return false; |
| name = name.substring(0, prefixLength + 1) + '*'; |
| } |
| } |
| |
| /** |
| * Enumerate over the collection. |
| * |
| * @return an enumeration of the collection contents |
| */ |
| public Enumeration elements() |
| { |
| return permissions.elements(); |
| } |
| } |