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Diffstat (limited to 'libjava/classpath/java/util/PropertyPermissionCollection.java')
| -rw-r--r-- | libjava/classpath/java/util/PropertyPermissionCollection.java | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/libjava/classpath/java/util/PropertyPermissionCollection.java b/libjava/classpath/java/util/PropertyPermissionCollection.java new file mode 100644 index 00000000000..c95fa4e66bf --- /dev/null +++ b/libjava/classpath/java/util/PropertyPermissionCollection.java @@ -0,0 +1,166 @@ +/* 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., 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.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(); + } +} |
