animator.java

这个程序能够模拟动画系统,其中使用了多线程,还有音乐伴奏

 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import java.net.URL;
import java.applet.*;

public class Animator extends JApplet implements ActionListener {
  JTextField jtfSpeed = new JTextField();
  JTextField jtfPrefix = new JTextField();
  JTextField jtfNumOfImages = new JTextField();
  JTextField jtfAudioFile = new JTextField();
  JButton jbtStartAnimation = new JButton("Start Animation");
  PlayImage playImage = new PlayImage();

  Image[] images;
  AudioClip audioClip;
  int sleepTime;
  int numOfImages;

   
  public void init() {
     
    JPanel p = new JPanel();
    p.setLayout(new GridLayout(4, 2));
    p.add(new JLabel("Animation speed in milliseconds"));
    p.add(jtfSpeed);
    p.add(new JLabel("Image file prefix (只存有g)"));
    p.add(jtfPrefix);
    p.add(new JLabel("Number of images (<=24)"));
    p.add(jtfNumOfImages);
    p.add(new JLabel("Audio file"));
    p.add(jtfAudioFile);
    p.setBorder(new TitledBorder(
      "Enter information for animation"));

     
    JPanel jpButton = new JPanel();
    jpButton.setLayout(new FlowLayout(FlowLayout.RIGHT));
    jpButton.add(jbtStartAnimation);

    JPanel p1 = new JPanel();
    JPanel p2 = new JPanel();
    JPanel p3 = new JPanel();
    p1.setLayout(new BorderLayout());
    p2.setLayout(new FlowLayout(FlowLayout.RIGHT));
    p2.add(jpButton);
    p1.add(p2,BorderLayout.NORTH);
    p1.add(playImage,BorderLayout.CENTER);
    
    getContentPane().setLayout(new GridLayout(2,1));
    getContentPane().add(p1  );
    getContentPane().add(p );

     
    jbtStartAnimation.addActionListener(this);
  }

   
  public void actionPerformed(ActionEvent e) {
    startAnimation();
  }

  public void startAnimation() {
    MediaTracker imageTracker = new MediaTracker(this);

     
    Toolkit toolkit = Toolkit.getDefaultToolkit();

    URL url = null;

    String prefix = jtfPrefix.getText().trim();
    numOfImages =
      new Integer(jtfNumOfImages.getText().trim()).intValue();
    String audioFile = jtfAudioFile.getText().trim();
    sleepTime = new Integer(jtfSpeed.getText().trim()).intValue();

     
    images = new Image[numOfImages];
    for (int i=0; i<images.length; i++) {
       
      url = this.getClass().getResource("image/" + prefix + (i+1)
        + ".gif");

      images[i] = toolkit.getImage(url);

       
      imageTracker.addImage(images[i], i);
    }

    
    try {
      url = this.getClass().getResource(audioFile);
    }
    catch (Exception ex) {
      System.out.println(ex);
    }
    System.out.println("url = " + url);

    audioClip = Applet.newAudioClip(url);

     
    try {
      imageTracker.waitForAll();
    }
    catch (InterruptedException ex) {
      System.out.println(ex);
    }

    
    imageTracker = null;

     
    playImage.beginAnimation();
  }

   
  public static void main(String[] args) {
     
    JFrame frame = new JFrame("Animator");

     
    Animator applet = new Animator();

    
    frame.getContentPane().add(applet, BorderLayout.CENTER);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    
    applet.init();
    applet.start();

    
    frame.setSize(500, 400);
    frame.setVisible(true);
  }

  class PlayImage extends JPanel implements Runnable {
    private Thread thread = null;
    int currentImageIndex = 0;
    Image imageToDisplay;

     
    protected boolean suspended = false;

     
    public PlayImage() {
       
      currentImageIndex = 0;

      thread = new Thread(this);

      setBorder(new LineBorder(Color.yellow, 1));
    }

    public void beginAnimation() {
      thread.start();
      if (audioClip != null) audioClip.loop();
    }

    public void start() {
      resume();
    }

    public void stop() {
      suspend();
    }

    public synchronized void resume() {
      if (suspended) {
        suspended = false;
        notify();
      }
    }

    public synchronized void suspend() {
      suspended = true;
    }

    public void destroy() {
      thread = null;
    }

    public void run() {
      while (true) {
        imageToDisplay =
          images[currentImageIndex%numOfImages];

         
        if (currentImageIndex == 0) currentImageIndex = 52;
        currentImageIndex = currentImageIndex + 1;
        repaint();

        try {
          thread.sleep(sleepTime);
          synchronized (this) {
            while (suspended)
              wait();
          }
        }
        catch (InterruptedException ex) {
        }
      }
    }

     
    public void paintComponent(Graphics g) {
      super.paintComponent(g);

      if (imageToDisplay != null) {
        g.drawImage(imageToDisplay, 0, 0, getSize().width,
          getSize().height, this);
      }
    }
  }
}