| An AccessControlContext is used to make system resource access decisions
based on the context it encapsulates.
More specifically, it encapsulates a context and
has a single method, checkPermission,
that is equivalent to the checkPermission method
in the AccessController class, with one difference: The AccessControlContext
checkPermission method makes access decisions based on the
context it encapsulates,
rather than that of the current execution thread.
Thus, the purpose of AccessControlContext is for those situations where
a security check that should be made within a given context
actually needs to be done from within a
different context (for example, from within a worker thread).
An AccessControlContext is created by calling the
AccessController.getContext method.
The getContext method takes a "snapshot"
of the current calling context, and places
it in an AccessControlContext object, which it returns. A sample call is
the following:
AccessControlContext acc = AccessController.getContext()
Code within a different context can subsequently call the
checkPermission method on the
previously-saved AccessControlContext object. A sample call is the
following:
acc.checkPermission(permission)
See Also: AccessController
author:
Roland Schemers | 