This class represents a heterogeneous collection of Permissions. That is,
it contains different types of Permission objects, organized into
PermissionCollections. For example, if any java.io.FilePermission
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
the newPermissionCollection method in the FilePermission class.
Similarly, any java.lang.RuntimePermission objects are stored in
the PermissionCollection returned by a call to the
newPermissionCollection method in the
RuntimePermission class. Thus, this class represents a collection of
PermissionCollections.
When the 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.
elements()
Returns an enumeration of all the Permission objects in all the
PermissionCollections in this Permissions object.
boolean
implies(Permission permission)
Checks to see if this object's PermissionCollection for permissions of the
specified permission's type implies the permissions
expressed in the permission object.
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.
Checks to see if this object's PermissionCollection for permissions of the
specified permission's type 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 implies method
is called with a permission specifying both "read" and "write" access
to files in the "/tmp/scratch/foo" directory, true is returned.
Additionally, if this PermissionCollection contains the
AllPermission, this method will always return true.
Submit a bug or feature For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Java, Java 2D, and JDBC are trademarks or registered trademarks of Sun Microsystems, Inc. in the US and other countries. Copyright 1993-2001 Sun Microsystems, Inc. 901 San Antonio Road Palo Alto, California, 94303, U.S.A. All Rights Reserved.