An example for deadlock : Synchronize « Thread « SCJP

1. SCJP
2. Thread
3. Synchronize

class MainClass implements Runnable {
  Object firstResource;

  Object secondResource;

  public MainClass(Object first, Object second) {
    firstResource = first;
    secondResource = second;
  }

  public void run() {
    while (true) {
      synchronized (firstResource) {
        synchronized (secondResource) {
          try {
            Thread.sleep(100);
          } catch (InterruptedException ex) {
          }
        }
      }
    }
  }

  public static void main(String[] args) {
    Object a = "Resource A";
    Object b = "Resource B";
    Thread t1 = new Thread(new MainClass(a, b));
    Thread t2 = new Thread(new MainClass(b, a));
    t1.start();
    t2.start();
  }
}