Throws a
SecurityException
if the
calling thread is not allowed to modify the thread group argument.
This method is invoked for the current security manager when a
new child thread or child thread group is created, and by the
setDaemon
, setMaxPriority
,
stop
, suspend
, resume
, and
destroy
methods of class ThreadGroup
.
If the thread group argument is the system thread group (
has a null
parent) then
this method calls checkPermission
with the
RuntimePermission("modifyThreadGroup")
permission.
If the thread group argument is not the system thread group,
this method just returns silently.
Applications that want a stricter policy should override this
method. If this method is overridden, the method that overrides
it should additionally check to see if the calling thread has the
RuntimePermission("modifyThreadGroup")
permission, and
if so, return silently. This is to ensure that code granted
that permission (such as the JDK itself) is allowed to
manipulate any thread.
If this method is overridden, then
super.checkAccess
should
be called by the first statement in the overridden method, or the
equivalent security check should be placed in the overridden method.
Parameters:
- g - the thread group to be checked.
Throws:
- SecurityException - if the calling thread does not have
permission to modify the thread group.
- NullPointerException - if the thread group argument is
null
.
See Also:
destroy
,
resume
,
setDaemon
,
setMaxPriority
,
stop
,
suspend
,
checkPermission
,