Java ThreadGroup destroy() method
The destroy() method of ThreadGroup class is used to destroy the thread group and all of its subgroups. The thread group must be empty, indicating that all threads that had been in the thread group have since stopped.
It doesn't return any value.
IllegalThreadStateException: This exception throws if the thread group is not empty or if the thread group has already been destroyed.
SecurityException: If the current thread cannot modify this thread group.
ExampleTest it Now
Thread-1 finished executing Thread-2 finished executing Child thread destroyed Parent thread destroyed