All Packages  Class Hierarchy  This Package  Previous  Next  Index  

Class java.security.Permissions

java.lang.Object
    |
    +----java.security.PermissionCollection
            |
            +----java.security.Permissions

public final class Permissions

extends PermissionCollection

implements Serializable

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 has a Permission object's name as the key, and the Permission object as the value.

See Also:

Permission, PermissionCollection

Permissions()

Creates a new Permissions object containing no PermissionCollections.

add(Permission)

Adds a permission object to the PermissionCollection for the class the permission belongs to.

elements()

Returns an enumeration of all the Permission objects in all the PermissionCollections in this Permissions object.

implies(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.

isReadOnly()

Returns true if this Permissions object is marked as readonly.

setReadOnly()

Marks this Permissions object as "readonly".

public Permissions()

Creates a new Permissions object containing no PermissionCollections.

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.

Parameters:

permission - the Permission object to add.

Throws: SecurityException

if this Permissions object is marked as readonly.

Overrides:

add in class PermissionCollection

See Also:

isReadOnly

public 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. 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.

Parameters:

permission - the Permission object to check.

Returns:

true if "permission" is implied by the permissions in the PermissionCollection it belongs to, false if not.

Overrides:

implies in class PermissionCollection

public Enumeration elements()

Returns an enumeration of all the Permission objects in all the PermissionCollections in this Permissions object.

Returns:

an enumeration of all the Permissions.

Overrides:

elements in class PermissionCollection

public void setReadOnly()

Marks this Permissions object as "readonly". After a Permissions object is marked as readonly, no new Permission objects can be added to it using addPermission.

public boolean isReadOnly()

Returns true if this Permissions object is marked as readonly. If it is readonly, no new Permission objects can be added to it using addPermission.

By default, the object is not readonly. It can be set to readonly by a call to setReadOnly.

Returns:

true if this Permissions object is marked as readonly, false otherwise.

All Packages  Class Hierarchy  This Package  Previous  Next  Index