Java 101之线程基础

class TestThreads {
  public static void main (String args []) {
     class MyThread extends Thread {
        String which;
        MyThread (String which)            {
        this.which = which;          
     }
     public void run() {
        int iterations = (int)(Math.random()*100) %15;
        int sleepinterval = (int)(Math.random()*1000);
        System.out.println(which + " running for " + iterations +" iterations");
        System.out.println(which + " sleeping for " + sleepinterval + "ms between loops");
        for (int i = 0; < iterations; i++) {
                      System.out.println(which +" " + i);
                              try {
                                  Thread.sleep(sleepinterval);
                              } catch (InterruptedException e) {}
                          }
                      }
       }

       MyThread a = new MyThread("Thread A");
       MyThread b = new MyThread("Thread B");
       MyThread c = new MyThread("Thread C");
       a.start();
       b.start();
       c.start();
   }
}

import java.applet.*;
import java.awt.*;

public class TstRunnable extends Applet
    implements Runnable {
  private Thread m_Thread = null;
  private Image m_Images[];
  private Image m_CurrentImage =null;
  private int m_nImgWidth = 0;
  private int m_nImgHeight = 0;
  private boolean m_fAllLoaded =  alse;
  private final int NUM_IMAGES = 18;

  public TstRunnable() { }
  private void displayImage(Graphics g) {
     if ( null != m_CurrentImage )
        g.drawImage(m_CurrentImage,(getSize().width - m_nImgWidth) / 2, 
                      (getSize().height - m_nImgHeight) / 2, null);
  }
  public void paint(Graphics g) {
     if (null != m_CurrentImage) {
        Rectangle r = g.getClipBounds();
        g.clearRect(r.x, r.y, r.width, r.height);
        displayImage(g);
    }
     else
        g.drawString("Loading images...", 10, 20);
  }
// The Applets start method is called when the page is first shown.
  public void start() {
     if (m_Thread == null) {
        m_Thread = new Thread(this);
        m_Thread.start();
     }
 }
// The Applets stop method is called when the page is hidden.
  public void stop() {
     if (m_Thread != null) {
        m_Thread.stop();
        m_Thread = null;
     }
  }
// The run method is used by the thread
//   object we created in this start method.
  public void run() {
     int iWhichImage = 0;
     Graphics m_Graphics = getGraphics();
     repaint();
     m_Graphics = getGraphics();
     m_Images   = newImage[NUM_IMAGES];
     MediaTracker tracker = new MediaTracker(this);
     String strImage;
     for (int i = 1; i <= NUM_IMAGES; i++) {
        m_Images[i-1] = getImage(getCodeBase(),          
                      "img" + new Integer(i).toString() + ".gif");
        tracker.addImage(m_Images[i-1],0);
     }
     try {
        tracker.waitForAll();
        m_fAllLoaded = !tracker.isErrorAny();
     } catch (InterruptedException e) {}
     if (!m_fAllLoaded) {
        stop();
        m_Graphics.drawString("Error loading images!", 10, 40);
        return;
     }
 // Assuming all images are the same          
 // width and height.
 //------------------------------------
     m_nImgWidth  = m_Images[0].getWidth(this);
     m_nImgHeight = m_Images[0].getHeight(this);
     repaint();
     while (true) {
        try {
// Draw next image in animation.
                      m_CurrentImage = m_Images[iWhichImage];
                      displayImage(m_Graphics);
                      iWhichImage = (iWhichImage+1) % NUM_IMAGES;
                      Thread.sleep(50);
        } catch (InterruptedException            e) {
                      stop();
        }
     }
 }
}