java.lang.Object | +--java.security.PermissionCollection | +--java.security.Permissions
Untamed:
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.
Enumerations returned via the elements method are
not fail-fast. Modifications to a collection should not be
performed while enumerating over that collection.
Permission,
PermissionCollection,
AllPermissionPermissions()
void
add(Permission permission)
Enumeration
elements()
private Enumeration
elements(Permission p)
private PermissionCollection
getPermissionCollection(Permission p)
private PermissionCollection
getUnresolvedPermissions(Permission p)
boolean
implies(Permission permission)
private Hashtable perms
private PermissionCollection allPermission
public Permissions()
public void add(Permission permission)
add in class PermissionCollectionpermission - the Permission object to add.PermissionCollection.isReadOnly()public boolean implies(Permission 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.
implies in class PermissionCollectionpermission - the Permission object to check.
public Enumeration elements()
elements in class PermissionCollectionprivate Enumeration elements(Permission p)
p - the prototype Permission object.
private PermissionCollection getPermissionCollection(Permission p)
newPermissionCollection method
on p. Subclasses of class Permission
override that method if they need to store their permissions in a
particular PermissionCollection object in order to provide the
correct semantics when the PermissionCollection.implies
method is called.
If the call returns a PermissionCollection, that collection is stored
in this Permissions object. If the call returns null, then
this method instantiates and stores a default PermissionCollection
that uses a hashtable to store its permission objects.
private PermissionCollection getUnresolvedPermissions(Permission p)
p - the type of unresolved permission to resolve