Thread

How to be notified once a thread finish? (JDK 1.5)
My forum
http://forum.java.sun.com/thread.jspa?threadID=5211762

public class TestThread implements Runnable {
  
  private BlockingQueue<String> q;
  
  public TestThread(BlockingQueue<String> q) {
    this.q = q;
  }
  
  public void run() {
    try {
      System.out.println("Bye, bye forum...");
      q.put("done");
    } catch(Exception ex) {
      ex.printStackTrace();
    }
  }
  
  public static void main(String[] args) throws Exception {
    BlockingQueue<String> q = new LinkedBlockingQueue<String>();
    TestThread r = new TestThread(q);
    Thread t = new Thread(r);
    t.start();
    Thread.sleep(1000);
    #Wait undefinitely
    String s = q.take();
    #Wait only 2 seconds max
    #String s = q.poll(2000, TimeUnit.MILLISECONDS);
    System.out.println("The thread " + s + " has finished");
  }
}

How to be notified once a thread finish? (Any JDK)
    
This my BlockingQueue version working with any JDK

public class MyBlockingQueue {

  private boolean done =false;
  private Object lock = new Object();
  
  public void threadIsDone() {
    done = true;
    synchronized(lock) {
      lock.notify();
    }
  }
  
  public boolean waitForThreadDone(long timeout) throws InterruptedException {
    synchronized(lock) {
      lock.wait(timeout);
    }
    return done;
  }
  
  public void waitForThreadDone() throws InterruptedException {
    while(!done) {
      synchronized(lock) {
        lock.wait();
      }
    }
  }

  public static void main(String[] args) throws Exception {
    args.getClass();
    MyBlockingQueue lock = new MyBlockingQueue();
    class MyThread extends Thread {
      MyBlockingQueue lock;
      public MyThread(MyBlockingQueue lock) {
        this.lock = lock;
      }
      public void run() {
        System.out.println("Thread done");
        lock.threadIsDone();
      }
    };
    MyThread t = new MyThread(lock);
    t.start();
    Thread.sleep(2000);
    lock.waitForThreadDone();
  }
}

Basic thread synchronization (lock - notify)

Thread main
    while(true) {
      synchronized(lock) {lock.wait(30000);}
      ...
    }
Thread n
    synchronized(lock) {
      lock.notify();
    }