欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

第一个JAVA小项目(太阳系行星运动模型)

程序员文章站 2022-07-13 11:03:37
...

1. 窗体的构建

对于游戏来说,需要构建一个桌面窗体,建立MyFrame类,继承Frame类,专用用于游戏窗体的构建。在MyFrame类中建立launchFrame()方法,用于实现窗口的生成。

这三行代码分别用于设置窗体大小,位置和可见的,这三个方法继承自Frame类。

            setSize(Constant.GAME_HEIGHT,Constant.GAME_WIDTH);
            setLocation(100, 100);
            setVisible(true);

定义内部类PaintThread继承Thread,重写Runnable接口方法run(),一直执行 repaint()函数,Thread.sleep(40)是让线程停止40ms。PaintThread().start()让线程的run()方法执行,可以实现窗口的动态更新。

         new PaintThread().start();

         class PaintThread extends Thread{
             public void run(){
                 while(true){
                     repaint();
                     try {
                        Thread.sleep(40);
                     } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                     }
                 }
             }
         }

在addWindowListener方法中定义内部类WindowAdapter,内部内重写了windowClosing()方法,用于窗体的退出(如果没有这个方法,窗体将无法退出)

addWindowListener(new WindowAdapter() {
                @Override
                public void windowClosing(WindowEvent e){
                    System.exit(0);
                }
            });
         }

窗体构建类MyFrame 的完整代码如下:


package com.zhong.util;

import java.awt.Frame;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;



public class MyFrame extends Frame {

       /**
        * 加载窗口    
       */
         public void launchFrame(){
            setSize(Constant.GAME_HEIGHT,Constant.GAME_WIDTH);
            setLocation(100, 100);
            setVisible(true);

            new PaintThread().start();
            addWindowListener(new WindowAdapter() {
                @Override
                public void windowClosing(WindowEvent e){
                    System.exit(0);
                }
            });
         }

         class PaintThread extends Thread{
             public void run(){
                 while(true){
                     repaint();
                     try {
                        Thread.sleep(40);
                     } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                     }
                 }
             }
         }


}

2. 工具类

定义常量类Constant,用于保存项目中的所有常量。代码如下:

package com.zhong.util;
/**
 * 常量
 * @author lenovo
 *
 */
public class Constant {
     public static final int GAME_WIDTH=800;
     public static final int GAME_HEIGHT=800;
}

定义 GameUtil类,用于一般工具的实现。里面的 getImage(String path)方法,用于从指定地址读取图片。完整代码如下:

package com.zhong.util;

import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;

import javax.imageio.ImageIO;

/**
 * 
 * 常用工具类
 * @author Kobe Zhong
 *
 */
public class GameUtil {
     private GameUtil(){

     }
     public static Image getImage(String path){
         URL  url=GameUtil.class.getClassLoader().getResource(path);
         BufferedImage img=null;
         try {
            img=ImageIO.read(url);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
         return img;
     }
}

3. 星球类

星球类Star是所有的星球所共有的属性。

定义星球的属性有图片(代表每种星球),坐标,宽度和长度(图片的)。代码如下:

    Image img;
    double x,y;
    int width,height;

定义星球类的重载构造函数,代码如下:

    public Star(){
    }
    public Star(Image img){
        this.img=img;

        this.width=img.getWidth(null);
        this.height=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);
    }

定义星球类的draw()方法,可以在窗体上画出星球的图片。代码如下:

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

星球类Star的完整代码如下:

package com.zhong.solar;

import java.awt.Graphics;
import java.awt.Image;

import com.zhong.util.GameUtil;

public class Star {
    Image img;
    double x,y;
    int width,height;
    public void draw(Graphics g){
        g.drawImage(img,(int)x,(int)y,null);
    }

    public Star(){
    }
    public Star(Image img){
        this.img=img;

        this.width=img.getWidth(null);
        this.height=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);
    }
}

4. 行星类

行星类Planet继承星球类Star,还拥有自己所特有的属性。

行星类包含长轴、短轴、运动速度、角度、中心恒星以及是否为卫星。属性定义代码如下:

    double longAxis;//长轴
    double shortAxis;//短轴
    double speed;
    double degree;//角度
    Star center;

    boolean isSattilite;

行星Planet的重载构造函数的代码如下:

    public Planet(Star center,String imgpath, double longAxis,double shortAxis, double speed) {

        super(GameUtil.getImage(imgpath));
        this.x=center.x+longAxis;
        this.y=center.y;
//      this.img=GameUtil.getImage(imgpath);
        this.shortAxis = shortAxis;
        this.longAxis = longAxis;
        this.speed = speed;
        this.center = center;
    }

    public Planet(Star center,String imgpath, double longAxis,double shortAxis, double speed,boolean isSattlite) {
        this(center, imgpath, longAxis,shortAxis,speed);
        this.isSattilite=isSattlite;

    }
    public Planet(Image img, double x, double y) {
        super(img, x, y);
        // TODO Auto-generated constructor stub
    }
    public Planet(String imgpath, double x, double y) {
        super(imgpath, x, y);
        // TODO Auto-generated constructor stub
    }

行星的运动是绕着恒星中心,做椭圆运动,其坐标变化的代码如下:

    public void move(){
        x=center.x+center.width/2+longAxis*Math.cos(degree);
        y=center.y+center.height/2+shortAxis*Math.sin(degree);

        degree+=speed;
    }

行星运动轨迹也是椭圆,根据中心位置和长短轴的大小,画出其轨迹即可,代码如下:

    public void drawTrace(Graphics g){
        double ovalX,ovalY,ovalWidth,ovalHeight;
        ovalWidth=longAxis*2;
        ovalHeight=shortAxis*2;
        ovalX=center.x+center.width/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);
    }

行星在窗体上的绘制重写父类Star的draw()方法,并调用move()坐标变化方法,还有是否为卫星的判断,不是卫星就画运动轨迹。具体代码如下:

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

行星类Planet的完整代码如下所示:

package com.zhong.solar;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;

import com.zhong.util.GameUtil;

public class Planet extends Star{
    double longAxis;//长轴
    double shortAxis;//短轴
    double speed;
    double degree;//角度
    Star center;

    boolean isSattilite;
    public void draw(Graphics g){
        super.draw(g);
        move();
        if(!isSattilite){
             drawTrace(g);
        }
    }
    public void drawTrace(Graphics g){
        double ovalX,ovalY,ovalWidth,ovalHeight;
        ovalWidth=longAxis*2;
        ovalHeight=shortAxis*2;
        ovalX=center.x+center.width/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);
    }

    public void move(){
        x=center.x+center.width/2+longAxis*Math.cos(degree);
        y=center.y+center.height/2+shortAxis*Math.sin(degree);

        degree+=speed;
    }
    public Planet(Star center,String imgpath, double longAxis,double shortAxis, double speed) {

        super(GameUtil.getImage(imgpath));
        this.x=center.x+longAxis;
        this.y=center.y;
//      this.img=GameUtil.getImage(imgpath);
        this.shortAxis = shortAxis;
        this.longAxis = longAxis;
        this.speed = speed;
        this.center = center;
    }

    public Planet(Star center,String imgpath, double longAxis,double shortAxis, double speed,boolean isSattlite) {
        this(center, imgpath, longAxis,shortAxis,speed);
        this.isSattilite=isSattlite;

    }
    public Planet(Image img, double x, double y) {
        super(img, x, y);
        // TODO Auto-generated constructor stub
    }
    public Planet(String imgpath, double x, double y) {
        super(imgpath, x, y);
        // TODO Auto-generated constructor stub
    }


}

5. 太阳系类(主方法)

定义SolarFrame为主类,继承MyFrame。

加载背景图片,并定义太阳,地球,火星,月球的对象,并初始化。代码如下:

         Image bg=GameUtil.getImage("images/bg.jpg");
         Star sun=new Star("images/sun.jpg", Constant.GAME_HEIGHT/2, Constant.GAME_WIDTH/2);
         Planet earth =new Planet(sun, "images/earth.jpg",100,50,0.1 ) ;
         Planet mars =new Planet(sun, "images/Mars.jpg",200,130,0.2 ) ;
         Planet moon=new Planet(earth,    "images/moon.jpg",20,13,0.01,true);

重写paint()方法,将背景图片,太阳,地球,火星和月球的图片绘制。(注意:paint()方法为回调方法,不需要在主函数调用它,在其父类的构造方法中已经调用,根据其所在对象重写的功能具体实现)

         public void paint(Graphics g){
             g.drawImage(bg,0,0,null);
             sun.draw(g);
             earth.draw(g);
             mars.draw(g);
             moon.draw(g);
         }

主方法中,定义SolarFrame对象,并调用它的launchFrame()方法(实现窗体的更新)。代码如下:

         public static void main(String[] args) {
            new SolarFrame().launchFrame();
        }
package com.zhong.solar;

import java.awt.Graphics;
import java.awt.Image;

import com.zhong.util.Constant;
import com.zhong.util.GameUtil;
import com.zhong.util.MyFrame; 

public class SolarFrame extends MyFrame{
         Image bg=GameUtil.getImage("images/bg.jpg");
         Star sun=new Star("images/sun.jpg", Constant.GAME_HEIGHT/2, Constant.GAME_WIDTH/2);
         Planet earth =new Planet(sun, "images/earth.jpg",100,50,0.1 ) ;
         Planet mars =new Planet(sun, "images/Mars.jpg",200,130,0.2 ) ;
         Planet moon=new Planet(earth,  "images/moon.jpg",20,13,0.01,true);
         public void paint(Graphics g){
             g.drawImage(bg,0,0,null);
             sun.draw(g);
             earth.draw(g);
             mars.draw(g);
             moon.draw(g);
         }

         public static void main(String[] args) {
            new SolarFrame().launchFrame();
        }
}

第一个JAVA小项目(太阳系行星运动模型)

相关标签: java