public class Lock
extends Object

For thread synchronization. Both methods MUST ALWAYS be called from within a statement synchronizing on this object, such as:

  final Lock lock = new Lock();
  synchronized (lock) {
      lock.lock();
      try {
        ... (do whatever needs be synchronized on this lock) ...
      } catch (Exception e) {
        e.printStackTrace();
      }
      lock.unlock();
  }
 

The advantage of using this class as opposed to a simple synchronized statement is that the lock may be set and unset from different synchronized blocks. For example:

  final Lock lock = new Lock();
  synchronized (lock) {
      lock.lock();
      // Do something
  }
  // Exit synchronized block, wait for other events to happen
  
  // ... 
  // Enter again and unlock:
  synchronized (lock) {
      try {
        ... (do whatever needs be synchronized on this lock) ...
      } catch (Exception e) {
        e.printStackTrace();
      }
      lock.unlock();
  }