java.security
Class PermissionCollection
java.lang.Object
|
+--java.security.PermissionCollection
All Implemented Interfaces:
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:Authors:- Aaron M. Renn <arenn@urbanophile.com>
- Eric Blake <ebb9@email.byu.edu>
See Also:
PermissionCollection
public PermissionCollection()
Create a new collection.
add
public void add(java.security.Permission perm)
This method adds a new Permission
object to the collection.
Parameters:
Throws:
elements
public Enumeration elements()
This method returns an Enumeration
of all the objects in
this collection.
Returns:
- an
Enumeration
of this collection's objects
implies
public boolean implies(java.security.Permission perm)
This method tests whether the specified Permission
object is
implied by this collection of Permission
objects.
Parameters:
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"
Returns:
- a
String
representing this object
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 returnsnull
, any type ofPermissionCollection
can be used to store permissions of that type. However, if aPermissionCollection
collection object is returned, that type must be used.A
PermissionCollection
returned by thenewPermissionCollection
method in a subclass ofPermission
is a homogeneous collection. It only will hold permissions of one specified type - instances of the class that created it. Not allPermissionCollection
subclasses have to hold permissions of only one type however. For example, thePermissions
class holds permissions of many types.Since the
newPermissionCollection
inPermission
itself returnsnull
, by default a permission can be stored in any type of collection unless it overrides that method to create its own collection type.