Can we start a Thread twice in Java?

Can we start a thread twice in Java? The answer is no, once a thread is started, it can never be started again. Doing so will throw an IllegalThreadStateException. Lets have a look at the below code:

public class ThreadTwiceExample implements Runnable {
   @Override
   public void run(){  
	Thread t = Thread.currentThread();
        System.out.println(t.getName()+" is executing.");
		    
   }  
   public static void main(String args[]){  
	Thread th1 = new Thread(new ThreadTwiceExample(), "th1"); 
	th1.start();  
	th1.start();  
   } 
}

Output:

Exception in thread "main" th1 is executing.
java.lang.IllegalThreadStateException

As you observe the first call to start() resulted in execution of run() method, however the exception got thrown when we tried to call the start() second time.