Java太阳系小游戏分析和源码详解

package util; 
 
public class Constant { 
  public static final int GAME_WIDTH = 800; 
  public static final int GAME_HEIGHT = 600; 
 
} 

package util; 
 
import java.awt.Image; 
import java.awt.image.BufferedImage; 
import java.io.IOException; 
import java.net.URL; 
 
import javax.imageio.ImageIO; 
 
/** 
 * 工具类（加载图片） 
 * @author long 
 * 
 */ 
public class GameUtil { 
 
  private GameUtil(){ } //工具类通常将构造方法私有 
   
  public static Image getImage(String path){ 
    URL u = GameUtil.class.getClassLoader().getResource(path); 
    BufferedImage img = null; 
    try { 
      img = ImageIO.read(u); 
    } catch (IOException e) { 
      e.printStackTrace(); 
    } 
    return img; 
  } 
} 

package util; 
 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
 
/** 
 * 游戏面板的父类 
 * @author long 
 * 
 */ 
public class MyFrame extends JPanel{ 
   
  /** 
   * 加载Frame的方法 
   */ 
  public void launchFrame(){ 
    JFrame frame = new JFrame("MyGame"); 
    frame.add(this); 
    frame.setSize(Constant.GAME_WIDTH,Constant.GAME_HEIGHT); 
    frame.setAlwaysOnTop(true); // 设置其总在最上 
    frame.setLocationRelativeTo(null); // 设置窗体初始位置 
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    frame.setVisible(true); 
     
    new PaintThread().start(); 
  } 
   
  /** 
   * 定义一个重画窗口的线程类，是一个内部类 
   * @author dell 
   * 
   */ 
  class PaintThread extends Thread { 
     
    public void run(){ 
      while(true){ 
        repaint(); 
        try { 
          Thread.sleep(40); //1s = 1000ms 
        } catch (InterruptedException e) { 
          e.printStackTrace(); 
        }   
      } 
    } 
     
  } 
   
  public static void main(String[] args) { 
    new MyFrame().launchFrame(); 
  } 
 
}

package solar; 
 
import java.awt.Color; 
import java.awt.Graphics; 
import java.awt.Image; 
 
import util.GameUtil; 
 
/** 
 * 行星类，继承至Star类 
 * @author long 
 * 
 */ 
public class Planet extends Star{ 
  //除了图片、坐标，行星沿着椭圆运行：长轴、短轴、移动速度、旋转角度。绕着某个star运行 
  double longAxis;  //椭圆长轴 
  double shortAxis; //椭圆短轴 
  double speed;   //飞行速度 
  double degree;   //旋转角度 
  Star center;    //围绕行星 
   
  public void draw(Graphics g){ 
    //g.drawImage(img, (int)x, (int)y, null); 
    super.draw(g); 
    drawTrace(g); 
    move(); 
  } 
   
  public void drawTrace(Graphics g){ 
    double traceX,traceY,traceWidth,traceHeight; 
    traceX = (center.x+center.w/2)-longAxis; 
    traceY = (center.y+center.h/2)-shortAxis; 
    traceWidth = 2*longAxis; 
    traceHeight = 2*shortAxis; 
     
    Color c = g.getColor(); 
    g.setColor(Color.blue); 
    g.drawOval((int)traceX, (int)traceY, (int)traceWidth, (int)traceHeight); 
    g.setColor(c); 
  } 
   
  public void move(){ 
    //沿着椭圆轨迹飞行 
    x = center.x + longAxis * Math.cos(degree); 
    y = center.y + shortAxis * Math.sin(degree); 
    degree += speed; 
  } 
   
  public Planet(Image img,double x,double y){ 
    super(img,x,y); 
  } 
  public Planet(String imgpath,double x,double y){ 
    super(imgpath,x,y); 
  } 
  public Planet( Star center,Image img,double longAxis, 
          double shortAxis,double speed) { 
    super(); 
    this.x = (center.x+center.w/2) + longAxis; 
    this.y = (center.y+center.h/2) + shortAxis; 
    this.img = img; 
    this.longAxis = longAxis; 
    this.shortAxis = shortAxis; 
    this.speed = speed; 
    this.center = center; 
  } 
  public Planet( Star center,String imgPath,double longAxis, 
        double shortAxis,double speed) { 
    this(center,GameUtil.getImage(imgPath),longAxis,shortAxis,speed); 
  } 
   
   
 
}

package solar; 
 
import java.awt.Graphics; 
import java.awt.Image; 
 
import util.Constant; 
import util.GameUtil; 
import util.MyFrame; 
 
public class SolarFrame extends MyFrame{ 
 
  int width = Constant.GAME_WIDTH/2; 
  int height = Constant.GAME_HEIGHT/2; 
   
  Image bg=GameUtil.getImage("images/bg.png"); 
   
  Star sun = new Star("images/sun.jpg",width,height); 
  Planet earth = new Planet(sun,"images/earth.png",100,60,0.1); 
  Planet mars = new Planet(sun,"images/mars.png",180,100,0.15); 
   
  @Override 
  public void paint(Graphics g) { 
    g.drawImage(bg, 0, 0, null); 
    sun.draw(g); 
    earth.draw(g);  
    mars.draw(g); 
  } 
 
  public static void main(String[] args) { 
    new SolarFrame().launchFrame(); 
  } 
 
} 

package solar; 
 
import java.awt.Graphics; 
import java.awt.Image; 
 
import util.GameUtil; 
 
public class Star { 
  public Image img; 
  public double x,y; 
  int w,h; 
   
  public void draw(Graphics g){ 
    g.drawImage(img, (int)x, (int)y, null); 
  } 
 
  public Star(){ 
  }   
  public Star(Image img){ 
    this.img = img; 
    this.w = img.getWidth(null); 
    this.h = img.getHeight(null); 
  } 
  public Star(Image img,double x,double y){ 
    this(img); 
    this.x = x; 
    this.y = y; 
  }   
  public Star(String imgPath,double x,double y){ 
    this(GameUtil.getImage(imgPath),x,y); 
  } 
   
}