threaddemo.java

金旭亮的java教案

import javax.swing.UIManager;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: </p>
 * @author not attributable
 * @version 1.0
 */

public class ThreadDemo {
  boolean packFrame = false;

  //Construct the application
  public ThreadDemo() {
    Frame1 frame = new Frame1();
    //Validate frames that have preset sizes
    //Pack frames that have useful preferred size info, e.g. from their layout
    if (packFrame) {
      frame.pack();
    }
    else {
      frame.validate();
    }
    //Center the window
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    Dimension frameSize = frame.getSize();
    if (frameSize.height > screenSize.height) {
      frameSize.height = screenSize.height;
    }
    if (frameSize.width > screenSize.width) {
      frameSize.width = screenSize.width;
    }
    frame.setLocation((screenSize.width - frameSize.width) / 2, (screenSize.height - frameSize.height) / 2);
    frame.setVisible(true);
  }
  //Main method
  public static void main(String[] args) {
    try {
      UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    }
    catch(Exception e) {
      e.printStackTrace();
    }
    new ThreadDemo();
  }
}


class Frame1 extends JFrame {
  JPanel contentPane;
  BorderLayout borderLayout1 = new BorderLayout();
  TextArea textArea1 = new TextArea();

  //Construct the frame
  public Frame1() {
    enableEvents(AWTEvent.WINDOW_EVENT_MASK);
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  //Component initialization
  private void jbInit() throws Exception  {
    contentPane = (JPanel) this.getContentPane();
    //使用内部类，实现线程
    class DemoThread implements Runnable
    {
      String name;
      Thread t;
      DemoThread(String Name_of_Thread)
      {
        name=Name_of_Thread;
        t=new Thread(this,name);
        textArea1.append("New Thread:"+t+"\n");
        t.start();//自动启动
      }
      public void run()
      {
        try
        {
          for (int i=4;i>0;i--)
          {
            textArea1.append(name+":"+i+"\n");
            Thread.sleep(1000);//等待一秒
          }
        }
        catch(InterruptedException e)
        {
          textArea1.append(name+" interrupted.\n");
        }
        textArea1.append(name+" exited.\n");
      }
    }

    DemoThread th1=new DemoThread("One");
    DemoThread th2=new DemoThread("Two");
    //(1) 创建第三个线程
    //DemoThread th3=new DemoThread("Three");

    textArea1.append("Thread One is alive:"+th1.t.isAlive()+"\n");
    textArea1.append("Thread Two is alive:"+th2.t.isAlive()+"\n");

   /* try
    {
      textArea1.append("Waiting for threads to finished.\n");
     //（3）如果去掉下面两句，会发生什么？
        // th1.t.join();
        // th2.t.join();
      //(2)  变换位置
    */
      //DemoThread th3=new DemoThread("Three");
    /*}
    catch(InterruptedException e)
    {
      textArea1.append("Main thread Interrupted\n");
    }*/
    textArea1.append("Thread One is alive:"+th1.t.isAlive()+"\n");
    textArea1.append("Thread Two is alive:"+th2.t.isAlive()+"\n");

    textArea1.append("MainTread Exited.");
    contentPane.setLayout(borderLayout1);

    this.setSize(new Dimension(400, 300));
    this.setTitle("Frame Title");
    contentPane.add(textArea1, BorderLayout.CENTER);
  }
  //Overridden so we can exit when window is closed
  protected void processWindowEvent(WindowEvent e) {
    super.processWindowEvent(e);
    if (e.getID() == WindowEvent.WINDOW_CLOSING) {
      System.exit(0);
    }
  }
}