A question about thread programming ...

Question

Is it possible to modify the following program such that the output is
ABCABCABC ...
I tried yield, but not getting results on every run.
The program is:
public class Example1 {
public static void main(String[] args) {
MyThread t1 = new MyThread("A");
MyThread t2 = new MyThread("B");
MyThread t3 = new MyThread("C");
t1.start();
t2.start();
t3.start();
class MyThread extends Thread {
private String message = "Hallo!";
public MyThread() {}
public MyThread(String s) {message = s;}
public void run() {
for (int i = 1; i <= 5; i++) {
System.out.print(message);
}

Answer 1

Not really, no. It's possible (not using yield) to force threads to run in a particular order, but it's kind of missing the point of using threads in the first place!
Yield is there purely to allow other threads the opportunity to run. It makes no guarantee about which thread will run next.
If you really must, you need to use a wait() call to force the thread to block, notifyAll calls to resurrect them, and some commonly accessed resource that allows each thread in turn to determine IF it is its turn to run when it is awakened by the notifyAll call. That seems to be the closest to the spirit of what you're trying to do.
It's a lot of work for something that you can more simply achieve by having only one thread of execution in the first place!