Causes this thread to begin execution; the Java Virtual Machine calls the
run
method of this thread.
The result is that two threads are running concurrently: the current thread (which returns from the call to the start
method) and the other thread (which executes its run
method).
It is never legal to start a thread more than once. In particular, a thread may not be restarted once it has completed execution.
@exception IllegalThreadStateException if the thread was alreadystarted.
@see #run()
@see #stop()