public final class Permissions extends PermissionCollection implements Serializable
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,
AllPermission| Constructor and Description |
|---|
Permissions()
Creates a new Permissions object containing no PermissionCollections.
|
| Modifier and Type | Method and Description |
|---|---|
void |
add(Permission permission)
Adds a permission object to the PermissionCollection for the class the
permission belongs to.
|
Enumeration<Permission> |
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 class implies the permissions
expressed in the permission object.
|
isReadOnly, setReadOnly, toStringpublic Permissions()
public void add(Permission permission)
add in class PermissionCollectionpermission - the Permission object to add.SecurityException - if this Permissions object is
marked as readonly.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<Permission> elements()
elements in class PermissionCollection