Java Programming Questions and Answers

Which of the following methods is not defined in the Thread class?

What would happen when a thread executes the following statement in its run() method?

sleep(500);

Consider the following code fragment:

1. public class ThreadTest {

2. public static void main(String[] args) {

3. Counter ct = new Counter();

4. ct.start();

5. System.out.println("The thread has been started");

6. }

7. }

8. class Counter extends Thread {

9. protected void run() {

10. System.out.println("Hello");

11. }

12. }

What would be the output of this code fragment?

Consider the following code:

1. public class ThreadOrder {

2. static int count=0;

3. public static void main(String[] args) {

4. Counter ct = new Counter();

5. Tracker trk1 = new Tracker(ct, "thread one");

6. Tracker trk2 = new Tracker(ct, "thread two");

7. trk1.start();

8. trk2.start();

9. }

10.}

11. class Tracker extends Thread {

12. Counter ct;

13. String message;

14. Tracker(Counter ct, String msg) {

15. this.ct = ct;

16. message = msg;

17. }

18. public void run() {

19. System.out.println(message);

20. }

21. }

22. class Counter {

23. private int count=0;

24. public int nextCounter() {

25. synchronized(this) {

26. count++;

27. return count;

28. }

29. }

30. }

What would be the output of this code fragment?

Which of the following is a method of the Object class?

Which of the following methods guarantee putting a thread out of the running state?

Which of the following is an invalid Thread constructor?