Implementing an Unbounded Work Queue with synchronized block : BlockingQueue « Thread « Java Tutorial

1. Java Tutorial
2. Thread
3. BlockingQueue

import java.util.LinkedList;

public class Main {
  public static void main(String[] argv) {
    WorkQueue queue = new WorkQueue();

    int numWorkers = 2;
    Worker[] workers = new Worker[numWorkers];
    for (int i = 0; i < workers.length; i++) {
      workers[i] = new Worker(queue);
      workers[i].start();
    }

    for (int i = 0; i < 100; i++) {
      queue.addWork(i);
    }
  }
}

class WorkQueue {
  LinkedList<Object> queue = new LinkedList<Object>();

  public synchronized void addWork(Object o) {
    queue.addLast(o);
    notify();
  }

  public synchronized Object getWork() throws InterruptedException {
    while (queue.isEmpty()) {
      wait();
    }
    return queue.removeFirst();
  }
}

class Worker extends Thread {
  WorkQueue q;

  Worker(WorkQueue q) {
    this.q = q;
  }

  public void run() {
    try {
      while (true) {
        Object x = q.getWork();

        if (x == null) {
          break;
        }
        System.out.println(x);
      }
    } catch (InterruptedException e) {
    }
  }
}