Java小案例（行星移动）

package my.university;


import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class MyFrame extends Frame {

    public void launchFram(){

        setSize(Content.Game_With,Content.Game_High);
        setLocation(100,100);
        setVisible(true);

        new PaintThread().start();

        addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
   private class  PaintThread extends Thread{
        public void run(){
            while(true){
                repaint();
                try {
                    Thread.sleep(50);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
   }

}

package my.university;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;


public class ImageUtil {
    private ImageUtil(){}//工具类构成私有的,?

    public static Image getImage(String path){
        URL url=ImageUtil.class.getResource(path);
        /*System.out.println(ImageUtil.class.getClassLoader().getResource(""));
        result is file:/d:/xxxxx/sparkDemo/sparksql/target/classes/*/
        BufferedImage image =null;
        try {
            image=ImageIO.read(url);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return image;
    }
}

package my.university;
public class Content {
    public static final int Game_With=500;
    public static final int Game_High=500;
}

package my.university;

import java.awt.*;

public class Start {
    public double x;
    public double y;
    public double with;
    public double height;
    Image image;

    public Start(){}//默认构造起，用于子类继承

    public Start(Image image){
        this.image=image;
        this.with=image.getWidth(null);
        this.height=image.getHeight(null);
    }
    public Start(Image image,double x,double y){
        this(image);
        this.x=x;
        this.y=y;
    }
    public Start(String path,double x,double y){
        this(ImageUtil.getImage(path),x,y);
    }

    public void draw(Graphics g){
        g.drawImage(image,(int)x,(int)y,null);
    }

}

package my.university;

import java.awt.*;

/**
 * Created by Administrator on 2017/8/12.
 */
public class Plant extends Start {
    double longAxis;  //椭圆的长轴
    double shortAxis;  //椭圆的短轴
    double speed;     //飞行的速度
    double degree;
    Start center;
    boolean statellite;

    public Plant(){}
    public Plant(Start center,String path,double longAxis,double shortAxis,double speed){
        super(ImageUtil.getImage(path));

        this.center=center;
        this.x=center.x+longAxis;
        this.y=center.y;

        this.longAxis=longAxis;
        this.shortAxis=shortAxis;
        this.speed=speed;;
    }
    public Plant(Start center,String path,double longAxis,double shortAxis,double speed,Boolean statellite){
       this(center, path, longAxis, shortAxis, speed);
       this.statellite=statellite;
    }

    public Plant(Image image){
        super(image);
    }
    public Plant(Image image,double x,double y){
        super(image, x, y);
    }

    //画轨迹
    public void drawTrace(Graphics g){
        double ovalX,ovalY,ovalWidth,ovalHeight;

        ovalWidth = longAxis*2;
        ovalHeight = shortAxis*2;
        ovalX = (center.x+center.with/2)-longAxis;
        ovalY = (center.y+center.height/2)-shortAxis;

        Color c=g.getColor();
        g.setColor(Color.blue);

        g.drawOval((int)ovalX,(int)ovalY,(int)ovalWidth,(int)ovalHeight);//定义矩形的左上角坐标及宽和高，在矩形中画椭圆
        g.setColor(c);
    }

    //移动
    public void move(){

        x=center.x+center.with/2+longAxis*Math.cos(degree);
        y=center.y+center.height/2+shortAxis*Math.sin(degree);
        degree+=speed;
    }

    public void draw(Graphics g){
        super.draw(g);
        move();
        if(!statellite){
            drawTrace(g);
        }


    }

}

package my.university;

import java.awt.*;
public class SolarFrame extends MyFrame {
    Image bg=ImageUtil.getImage("images/bg.jpg");
    Start sun=new Start("images/sun.jpg",Content.Game_With/2,Content.Game_High/2);
    Plant mercurys = new Plant(sun, "images/Mercury.jpg", 50, 30, 0.2);
    Plant venus = new Plant(sun, "images/Venus.jpg", 60, 40, 0.3);
    Plant earth=new Plant(sun,"images/Earth.jpg",100,50,0.4);
    Plant mars = new Plant(sun, "images/Mars.jpg", 120, 60, 0.5);
    Plant jupiter = new Plant(sun, "images/jupiter.jpg", 140, 70, 0.6);
    Plant saturn =new Plant(earth,"images/Saturn.jpg",160,80,0.7,true);
    Plant uranus = new Plant(sun, "images/Uranus.jpg", 180, 90, 0.8);
    Plant neptune = new Plant(sun, "images/Neptune.jpg", 200, 100, 0.9);
    Plant moon = new Plant(earth, "images/moon.jpg", 30, 20, 0.3,true);
    public void paint(Graphics g){
        g.drawImage(bg,0,0,null);

        sun.draw(g);
        mercurys.draw(g);
        venus.draw(g);
        earth.draw(g);
        mars.draw(g);
        jupiter.draw(g);
        saturn.draw(g);
        uranus.draw(g);
        neptune.draw(g);
        moon.draw(g);
    }
    public static void main(String[] args){
        new SolarFrame().launchFram();
    }
}