特定通知パターンを適用してスレッドの実行順序を制御する

import java.util.*;                                              //1
class Robot extends Thread
{
  private RobotController controller;
  private int robotID;
  private byte[] lock;                                           //2

  public Robot(RobotController cntrl, int id)
  {
    controller = cntrl;
    robotID = id;
  }

  public byte[] getLock()                                        //3
  {                                                              //4
    return lock;                                                 //5
  }                                                              //6

  public void run()
  {
    lock = new byte[0];                                          //7
    synchronized(lock)                                           //8
    {
      byte[] data;
      while ((data = controller.getData()) == null)
      {
        try {
          System.out.println("Thread " + robotID + " waiting");
          lock.wait();                                           //9
        }
        catch (InterruptedException ie) {}
      }
      //Now we have data to move the robot
      System.out.println("Robot " + robotID + " Working");
    }
  }
}

class RobotController
{
  private byte[] robotData;
  private Vector threadList = new Vector();                      //10
  private Robot rbot1;
  private Robot rbot2;
  private Robot rbot3;
  private Robot rbot4;
  private Robot rbot5;

  public static void main(String args[])
  {
    RobotController controller = new RobotController();
    controller.setup();
  }

  public void setup()
  {
    rbot1 = new Robot(this, 1);
    rbot2 = new Robot(this, 2);
    rbot3 = new Robot(this, 3);
    rbot4 = new Robot(this, 4);
    rbot5 = new Robot(this, 5);
    threadList.addElement(rbot1);                                //11
    threadList.addElement(rbot2);                                //12
    threadList.addElement(rbot3);                                //13
    threadList.addElement(rbot4);                                //14
    threadList.addElement(rbot5);                                //15
    rbot3.setPriority(Thread.MAX_PRIORITY);
    rbot1.start();
    rbot2.start();
    rbot3.start();
    rbot4.start();
    rbot5.start();
    begin();
  }
  
  public void begin()
  {
    for (int i=4;i>=0;i--)                                    //16
    {
      try {
        Thread.sleep(500);
      }
      catch (InterruptedException ie){}
      putData(new byte[10]);

      Robot rbot = (Robot)threadList.elementAt(i);               //17
      byte[] robotLock = rbot.getLock();                         //18
      synchronized(robotLock) {                                  //19
        System.out.println("Calling notify");       
        robotLock.notify();                                      //20
      }
    }
  }

  public synchronized byte[] getData()                           //21
  {
    if (robotData != null)
    {
      byte[] d = new byte[robotData.length];
      System.arraycopy(robotData, 0, d, 0, robotData.length);
      robotData = null;
      return d;
    }
    return null;
  }

  public void putData(byte[] d)
  {
    robotData = d;
  }
}