Threading Demo

FooThread.java

import java.util.Random;

class FooThread extends Thread {
  int threadNum;
  Random random;

  FooThread(int threadNum) {
    this.threadNum = threadNum;
    this.random = new Random(System.currentTimeMillis() + threadNum);
  }

  public void run() {
    for (int i = 0; i < 5; i++) {
      int sleepSeconds = random.nextInt(5);
      System.out.printf("Thread #%d, sleeping for %d seconds\n", threadNum,
        sleepSeconds);
      try {
        Thread.sleep(sleepSeconds * 1000);
      } catch (InterruptedException ie) {
        System.out.println("Thread was interrupted: " + ie);
      }
    }
    System.out.printf("Thread #%d done.\n", threadNum);
  }
}

class FooRunnable implements Runnable {
  int threadNum;
  Random random;
  Object lockObject;

  FooRunnable(int threadNum, Object lockObject) {
    this.threadNum = threadNum;
    this.random = new Random(System.currentTimeMillis() + threadNum);
    this.lockObject = lockObject;
  }

  public void run() {
    synchronized (lockObject) {
      for (int i = 0; i < 5; i++) {
        int sleepSeconds = random.nextInt(5);
        System.out.printf("Thread #%d, sleeping for %d seconds\n", threadNum,
          sleepSeconds);
        try {
          Thread.sleep(sleepSeconds * 1000);
        } catch (InterruptedException ie) {
          System.out.println("Thread was interrupted: " + ie);
        }
      }
    }
    System.out.printf("Thread #%d done.\n", threadNum);
  }
}

TestThread.java

public class TestThread {

  public static void doSomething(Object lockObject) {
    Thread t1 = new Thread(new FooRunnable(3, lockObject));
    Thread t2 = new Thread(new FooRunnable(4, lockObject));
    t2.start();
    t1.start();
    // t2.start();
  }

  public static void main(String[] args) throws InterruptedException {
    Integer fooObject = 1, fooObject2 = 2;
    doSomething(fooObject);
    //FooThread t1 = new FooThread(1);
    // FooThread t2 = new FooThread(2);
    Thread t1 = new Thread(new FooRunnable(1, fooObject));
    Thread t2 = new Thread(new FooRunnable(2, fooObject));
    t1.start();
    t2.start();
    // t1.join();
    // t2.join();
  }
}