playoneball.java

主要是对于JAVA的编程的基本语言 希望能够帮得上你。

package applet;
import java.awt.Color;
import java.awt.Graphics;  //画笔
import java.applet.Applet; //经编译后可嵌入HTML文件
import java.applet.AudioClip;
import java.awt.*;
import java.awt.event.*;

public class PlayOneBall extends Applet implements Runnable, ActionListener{
	
	private Thread timer;	
	int BallDiameter;  //定义小球直径
	int StepLength;    //定义移动步长
	float x, y;  //定义小球坐标
	double angle; //定义小球运动方向角，以水平向右为初始方向
	boolean started=false;	
	AudioClip sound;	
	Button btnStart=new Button("开始");
	Button btnStop=new Button("停止");	
	Button btnExit=new Button("退出");
	
	public void init(){	
		
		this.setSize(500,500);	
		this.add(btnStart);
		this.add(btnStop);
		this.add(btnExit);
		btnStart.addActionListener(this);
		btnStop.addActionListener(this);		
		btnExit.addActionListener(this);
		
		sound=this.getAudioClip(this.getCodeBase(),"applet/ding.wav");		
	}	
	
	public void update(Graphics g){
		paint(g);
	}
	
	public void paint(Graphics g){		
		g.setColor(Color.YELLOW);
		g.fillRect(0, 0, this.getWidth(),this.getHeight());
		g.setColor(Color.RED);
		g.fillArc(Math.round(x), Math.round(y), BallDiameter, BallDiameter, 0, 360);		
	}
	
	public void start() {
        timer = new Thread(this);
        timer.start();  
        
        x=(float) (Math.random()*this.getWidth()*0.8); //定义小球初始横坐标
		y=(float) (Math.random()*this.getHeight()*0.8);	//定义小球初始纵坐标
        angle=Math.random()*Math.PI*2;	//定义小球运动初始角
        BallDiameter=(int) (Math.random()*50+30); //定义小球的直径
    	StepLength=(int) (Math.random()*10+5); //定义小球的移动步长
    }   

    public void run() {        
        while (timer == Thread.currentThread() && started) {
            try {
                timer.sleep(50);
            } catch (InterruptedException e) {
            }
            
            //小球运动方向和坐标的变化            
            if(x<StepLength || x>this.getWidth()-BallDiameter){            	
            	sound.play();            	         
            	angle=Math.PI-angle;
            }            
            if(y<StepLength || y>this.getHeight()-BallDiameter){            	
            	sound.play();            	
            	angle=2*Math.PI-angle;
            }           
            x=(float) (x+StepLength*Math.cos(angle));
            y=(float) (y-StepLength*Math.sin(angle));
            
            repaint(); //重绘
        }
    }

	public void actionPerformed(ActionEvent e) {
		if(e.getSource()==btnStart){
			started=true;
			sound.play();
			start();			
		}else if(e.getSource()==btnStop){
			started=false;
			sound.stop();
			stop();
		}else
			System.exit(0);		
	}
}