24 times runing... gets printed.but i couln't get the rules behing this.
Sometimes 30, 35, and 20, no guarantee. You have made the thread daemon using setDaemon(true).
Straight from JavaDoc:
public final void setDaemon(boolean on)
Marks this thread as either a daemon thread or a user thread. The Java Virtual Machine exits when the only threads running are all daemon threads.
This method must be called before the thread is started
When a Java Virtual Machine starts up, there is usually a single non-daemon thread (which typically calls the method named main of some designated class). The Java Virtual Machine continues to execute threads until either of the following occurs:
* The exit method of class Runtime has been called and the security manager has permitted the exit operation to take place. * All threads that are not daemon threads have died, either by returning from the call to the run method or by throwing an exception that propagates beyond the run method.