java.security

Class PermissionCollection

java.lang.Object

java.security.PermissionCollection

All Implemented Interfaces:

Serializable

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

Author:

Aaron M. Renn , Eric Blake

See Also:

Permission, Permissions, Serialized Form

Constructor Summary

Constructors

Constructor and Description
PermissionCollection() Create a new collection.

Method Summary

Modifier and Type	Method and Description
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, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

PermissionCollection

public PermissionCollection()

Create a new collection.

Method Detail

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

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

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

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.

isReadOnly

public boolean isReadOnly()

This method tests whether or not this PermissionCollection object is read only.

Returns:

true if this collection is read only

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 class Object

Returns:

a String representing this object