Java Thread Execution sequence control

		thread T1 = new Thread (new Runnable () {

			@Override public
			void Run () {
				System.out.println ("T1");
			}
		); Thread
		t2 = new Thread (new Runnable () {

			@Override public
			void Run () {
				try {
					//reference T1 thread, waiting for T1 thread to finish executing 
 t1.join ();
				} catch (Interruptedexception e) {
					e.printstacktrace ();
				}
				System.out.println ("T2");
			}
		);
		thread t3 = new Thread (new Runnable () {

			@Override public
			void Run () {
				try {
					//reference t2 thread, waiting for the T2 thread to finish
					executing T2.join ();
				} catch (Interruptedexception e) {
					e.printstacktrace ();
				}
				System.out.println ("T3");
			}
		);
		T3.start ();
		T2.start ();
		T1.start ();

If there are three threads t1,t2,t3, how to ensure that T2 is performed before T3, T1 done before T2.

The Join method is used to refer to threads in this thread that need to be joined in execution, so that the incoming thread can be executed first.