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java.security

Class PermissionCollection

Implemented Interfaces:
Serializable
Known Direct Subclasses:
Permissions
public abstract class PermissionCollection
extends Object
implements Serializable
This class models a group of Java permissions. It has convenient methods for determining whether or not a given permission is implied by any of the permissions in this collection.

Some care must be taken in storing permissions. First, a collection of the appropriate type must be created. This is done by calling the newPermissionCollection method on an object of the permission class you wish to add to the collection. If this method returns null, any type of PermissionCollection can be used to store permissions of that type. However, if a PermissionCollection collection object is returned, that type must be used.

A PermissionCollection returned by the newPermissionCollection method in a subclass of Permission is a homogeneous collection. It only will hold permissions of one specified type - instances of the class that created it. Not all PermissionCollection subclasses have to hold permissions of only one type however. For example, the Permissions class holds permissions of many types.

Since the newPermissionCollection in Permission itself returns null, by default a permission can be stored in any type of collection unless it overrides that method to create its own collection type.

Since:
1.1
See Also:
Permission, Permissions, Serialized Form

Constructor Summary

PermissionCollection()
Create a new collection.

Method Summary

abstract void
add(Permission perm)
This method adds a new Permission object to the collection.
abstract Enumeration
elements()
This method returns an Enumeration of all the objects in this collection.
abstract boolean
implies(Permission perm)
This method tests whether the specified Permission object is implied by this collection of Permission objects.
boolean
isReadOnly()
This method tests whether or not this PermissionCollection object is read only.
void
setReadOnly()
This method sets this PermissionCollection object to be read only.
String
toString()
This method returns a String representation of this collection.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

PermissionCollection

public PermissionCollection()
Create a new collection.

Method Details

add

public abstract void add(Permission perm)
This method adds a new Permission object to the collection.
Parameters:
perm - the Permission to add
Throws:
SecurityException - if the collection is marked read only
IllegalArgumentException - if perm is of the wrong type

elements

public abstract Enumeration elements()
This method returns an Enumeration of all the objects in this collection.
Returns:
an Enumeration of this collection's objects

implies

public abstract boolean implies(Permission perm)
This method tests whether the specified Permission object is implied by this collection of Permission objects.
Parameters:
perm - the Permission object to test
Returns:
true if the collection implies perm

isReadOnly

public boolean isReadOnly()
This method tests whether or not this PermissionCollection object is read only.
Returns:
true if this collection is read only

setReadOnly

public void setReadOnly()
This method sets this PermissionCollection object to be read only. No further permissions can be added to it after calling this method.

toString

public String toString()
This method returns a String representation of this collection. It is formed by: 
 super.toString()" (\n"
   // enumerate all permissions, one per line
 ")\n"
Overrides:
toString in interface Object
Returns:
a String representing this object
PermissionCollection.java -- A collection of permission objects Copyright (C) 1998, 2001, 2002, 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.

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