ballthread.java

JAVA入门的一些基本写法以及一些入门的简单代码 由于本人只是初学者

package test;

import java.awt.*;
import java.lang.*;
import java.awt.event.*;
import java.util.*;


public class BallThread extends Frame{

     public BallThread(){
       setSize(300,200);
       setTitle("多线程动画");

       addWindowListener(new WindowAdapter(){
                   public void windowClosing(WindowEvent e){
                           System.exit(0);
                    }
                                            }
                        );
       final MainPanel canvas=new MainPanel();
        canvas.balls=new Vector();
        add((Panel)canvas,"Center") ;
        Panel p=new Panel();
        addButton(p,"Start",new ActionListener(){
                        public  void actionPerformed(ActionEvent evt){
                                   Ball b=new Ball(canvas);
                                   canvas.balls.add(b);
                                   b.start();


                          }
                                                }
                 );
        addButton(p,"Close",new ActionListener(){
                        public  void actionPerformed(ActionEvent evt){
                                   canvas.setVisible(false);
                                   System.exit(0);
                          }
                                                }
                 );
         add(p,"South");
    }
    class MainPanel extends Panel{
        public Vector balls;
        synchronized public void paint(Graphics g){

            paintBalls();
        }
        public void paintBalls(){
            Enumeration ballCollection =balls.elements();
           while(ballCollection.hasMoreElements() ){
               Ball ball=(Ball)ballCollection.nextElement();
               ball.draw();
            }
        }
    }


    public  void addButton(Container c,String title,ActionListener a){
         Button b=new Button(title);
         c.add(b);
         b.addActionListener(a);
    }
     class Ball extends Thread{
        MainPanel mainpanel;
       private static final int XSIZE=10;
       private static final int YSIZE=10;
       private int x=0;
       private int y=0;
       private int dx=2;
       private int dy=2;
       public Ball(MainPanel b){ mainpanel=b;}
       public void draw(){
           Graphics g=mainpanel.getGraphics();
           g.fillOval(x,y,XSIZE,YSIZE);
           g.dispose();
       }
       public void move(){
          if (!mainpanel.isVisible() )  return;
           x+=dx;
           y+=dy;
           Dimension d=mainpanel.getSize();
          if(x<0){x=0;dx=-dx;}
          if(y<0){y=0;dy=-dy;}
          if(x+XSIZE>=d.width ) {x=d.width -XSIZE;dx=-dx;}
          if(y+YSIZE>=d.height ) {y=d.height -YSIZE;dy=-dy;}
           mainpanel.repaint();
       }
       public void run(){
          try{
               draw();
               for(int i=0;i<=1000;i++){
                    move();
                    sleep(50);
                }
           }catch(Exception e){
           }
       }
    }


    public static void main(String[] args){
       Frame frame=new BallThread();
       frame.show();
   }
}