Java > Threads > Thread syncronization

public class TwoObjects extends Object {
  private String objID;

  public TwoObjects(String objID) {
    this.objID = objID;
  }

  public synchronized void synchronizedMethod(int val) {
    print("entering synchronized method()");
    int num = val * 2 + objID.length();
    print("in doStuff() - local variable num=" + num);

    try {
      Thread.sleep(2000);
    } catch (InterruptedException x) {
    }

    print("leaving synchronized method");
  }

  public void print(String msg) {
    threadPrint("objID=" + objID + " - " + msg);
  }

  public static void threadPrint(String msg) {
    String threadName = Thread.currentThread().getName();
    System.out.println(threadName + ": " + msg);
  }

  public static void main(String[] args) {
    final TwoObjects obj1 = new TwoObjects("obj1");
    final TwoObjects obj2 = new TwoObjects("obj2");

    Runnable runA = new Runnable() {
      public void run() {
        obj1.synchronizedMethod(3);
      }
    };

    Thread threadA = new Thread(runA, "threadA");
    threadA.start();

    try {
      Thread.sleep(200);
    } catch (InterruptedException x) {
    }

    Runnable runB = new Runnable() {
      public void run() {
        obj2.synchronizedMethod(7);
      }
    };

    Thread threadB = new Thread(runB, "threadB");
    threadB.start();
  }
}