public final class: Permissions
All Implemented Interfaces:
This class represents a heterogeneous collection of Permissions. That is,
it contains different types of Permission objects, organized into
PermissionCollections. For example, if any
objects are added to an instance of
this class, they are all stored in a single
PermissionCollection. It is the PermissionCollection returned by a call to
method in the FilePermission class.
stored in the PermissionCollection returned by a call to the
method in the
RuntimePermission class. Thus, this class represents a collection of
add method is called to add a Permission, the
Permission is stored in the appropriate PermissionCollection. If no such
collection exists yet, the Permission object's class is determined and the
newPermissionCollection method is called on that class to create
the PermissionCollection and add it to the Permissions object. If
newPermissionCollection returns null, then a default
PermissionCollection that uses a hashtable will be created and used. Each
hashtable entry stores a Permission object as both the key and the value.
Enumerations returned via the
elements method are
not fail-fast. Modifications to a collection should not be
performed while enumerating over that collection.
| PermissionCollection ||allPermission || |
Creates a new Permissions object containing no PermissionCollections.
|Methods from java.lang.Object:|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait|
|Method from java.security.Permissions Detail:|
public void add(Permission permission)
Adds a permission object to the PermissionCollection for the class the
permission belongs to. For example, if permission is a
FilePermission, it is added to the FilePermissionCollection stored
in this Permissions object.
This method creates
a new PermissionCollection object (and adds the permission to it)
if an appropriate collection does not yet exist.
public Enumeration<Permission> elements()
Returns an enumeration of all the Permission objects in all the
PermissionCollections in this Permissions object.
public boolean implies(Permission permission)
Checks to see if this object's PermissionCollection for permissions of
the specified permission's class implies the permissions
expressed in the permission object. Returns true if the
combination of permissions in the appropriate PermissionCollection
(e.g., a FilePermissionCollection for a FilePermission) together
imply the specified permission.
For example, suppose there is a FilePermissionCollection in this
Permissions object, and it contains one FilePermission that specifies
"read" access for all files in all subdirectories of the "/tmp"
directory, and another FilePermission that specifies "write" access
for all files in the "/tmp/scratch/foo" directory.
Then if the
is called with a permission specifying both "read" and "write" access
to files in the "/tmp/scratch/foo" directory,
Additionally, if this PermissionCollection contains the
AllPermission, this method will always return true.