import java.util.Random;


 敵飛機(jī): 是飛行物，也是敵人

public class Airplane extends FlyingObject implements Enemy {
 private int speed = 3; //移動步驟

 /** 初始化數(shù)據(jù) */
 public Airplane(){
  this.image = ShootGame.airplane;
  width = image.getWidth();
  height = image.getHeight();
  y = -height;   
  Random rand = new Random();
  x = rand.nextInt(ShootGame.WIDTH - width);
 }

 /** 獲取分?jǐn)?shù) */
 @Override
 public int getScore() { 
  return 5;
 }

 /** //越界處理 */
 @Override
 public  boolean outOfBounds() { 
  return y>ShootGame.HEIGHT;
 }

 /** 移動 */
 @Override
 public void step() { 
  y += speed;
 }

}

/** 
 * 獎勵 
 */ 
public interface Award { 
 int DOUBLE_FIRE = 0; //雙倍火力 
 int LIFE = 1; //1條命 
 /** 獲得獎勵類型(上面的0或1) */ 
 int getType(); 
}

import java.util.Random; 

/** 蜜蜂 */ 
public class Bee extends FlyingObject implements Award{ 
 private int xSpeed = 1; //x坐標(biāo)移動速度 
 private int ySpeed = 2; //y坐標(biāo)移動速度 
 private int awardType; //獎勵類型 

 /** 初始化數(shù)據(jù) */ 
 public Bee(){ 
  this.image = ShootGame.bee; 
  width = image.getWidth(); 
  height = image.getHeight(); 
  y = -height; 
  Random rand = new Random(); 
  x = rand.nextInt(ShootGame.WIDTH - width); 
  awardType = rand.nextInt(2); //初始化時給獎勵 
 } 

 /** 獲得獎勵類型 */ 
 public int getType(){ 
  return awardType; 
 } 

 /** 越界處理 */ 
 @Override 
 public boolean outOfBounds() { 
  return y>ShootGame.HEIGHT; 
 } 

 /** 移動，可斜著飛 */ 
 @Override 
 public void step() {  
  x += xSpeed; 
  y += ySpeed; 
  if(x > ShootGame.WIDTH-width){ 
   xSpeed = -1; 
  } 
  if(x < 0){ 
   xSpeed = 1; 
  } 
 } 
}

/** 
 * 子彈類:是飛行物 
 */ 
public class Bullet extends FlyingObject { 
 private int speed = 3; //移動的速度 

 /** 初始化數(shù)據(jù) */ 
 public Bullet(int x,int y){ 
  this.x = x; 
  this.y = y; 
  this.image = ShootGame.bullet; 
 } 

 /** 移動 */ 
 @Override 
 public void step(){  
  y-=speed; 
 } 

 /** 越界處理 */ 
 @Override 
 public boolean outOfBounds() { 
  return y<-height; 
 } 

}

/** 
 * 敵人，可以有分?jǐn)?shù) 
 */ 
public interface Enemy { 
 /** 敵人的分?jǐn)?shù) */ 
 int getScore(); 
}

import java.awt.image.BufferedImage; 

/** 
 * 飛行物(敵機(jī)，蜜蜂，子彈，英雄機(jī)) 
 */ 
public abstract class FlyingObject { 
 protected int x; //x坐標(biāo) 
 protected int y; //y坐標(biāo) 
 protected int width; //寬 
 protected int height; //高 
 protected BufferedImage image; //圖片 

 public int getX() { 
  return x; 
 } 

 public void setX(int x) { 
  this.x = x; 
 } 

 public int getY() { 
  return y; 
 } 

 public void setY(int y) { 
  this.y = y; 
 } 

 public int getWidth() { 
  return width; 
 } 

 public void setWidth(int width) { 
  this.width = width; 
 } 

 public int getHeight() { 
  return height; 
 } 

 public void setHeight(int height) { 
  this.height = height; 
 } 

 public BufferedImage getImage() { 
  return image; 
 } 

 public void setImage(BufferedImage image) { 
  this.image = image; 
 } 

 /** 
  * 檢查是否出界 
  * @return true 出界與否 
  */ 
 public abstract boolean outOfBounds(); 

 /** 
  * 飛行物移動一步 
  */ 
 public abstract void step(); 

 /** 
  * 檢查當(dāng)前飛行物體是否被子彈(x,y)擊(shoot)中 
  * @param Bullet 子彈對象 
  * @return true表示被擊中了 
  */ 
 public boolean shootBy(Bullet bullet){ 
  int x = bullet.x; //子彈橫坐標(biāo) 
  int y = bullet.y; //子彈縱坐標(biāo) 
  return this.x<x && x<this.x+width && this.y<y && y<this.y+height; 
 } 

}

import java.awt.image.BufferedImage; 

/** 
 * 英雄機(jī):是飛行物 Java學(xué)習(xí)交流QQ群：589809992 我們一起學(xué)Java！
 */ 
public class Hero extends FlyingObject{ 

 private BufferedImage[] images = {}; //英雄機(jī)圖片 
 private int index = 0;    //英雄機(jī)圖片切換索引 

 private int doubleFire; //雙倍火力 
 private int life; //命 

 /** 初始化數(shù)據(jù) */ 
 public Hero(){ 
  life = 3; //初始3條命 
  doubleFire = 0; //初始火力為0 
  images = new BufferedImage[]{ShootGame.hero0, ShootGame.hero1}; //英雄機(jī)圖片數(shù)組 
  image = ShootGame.hero0; //初始為hero0圖片 
  width = image.getWidth(); 
  height = image.getHeight(); 
  x = 150; 
  y = 400; 
 } 

 /** 獲取雙倍火力 */ 
 public int isDoubleFire() { 
  return doubleFire; 
 } 

 /** 設(shè)置雙倍火力 */ 
 public void setDoubleFire(int doubleFire) { 
  this.doubleFire = doubleFire; 
 } 

 /** 增加火力 */ 
 public void addDoubleFire(){ 
  doubleFire = 40; 
 } 

 /** 增命 */ 
 public void addLife(){ //增命 
  life++; 
 } 

 /** 減命 */ 
 public void subtractLife(){ //減命 
  life--; 
 } 

 /** 獲取命 */ 
 public int getLife(){ 
  return life; 
 } 

 /** 當(dāng)前物體移動了一下，相對距離，x,y鼠標(biāo)位置 */ 
 public void moveTo(int x,int y){  
  this.x = x - width/2; 
  this.y = y - height/2; 
 } 

 /** 越界處理 */ 
 @Override 
 public boolean outOfBounds() { 
  return false; 
 } 

 /** 發(fā)射子彈 */ 
 public Bullet[] shoot(){  
  int xStep = width/4;  //4半 
  int yStep = 20; //步 
  if(doubleFire>0){ //雙倍火力 
   Bullet[] bullets = new Bullet[2]; 
   bullets[0] = new Bullet(x+xStep,y-yStep); //y-yStep(子彈距飛機(jī)的位置) 
   bullets[1] = new Bullet(x+3*xStep,y-yStep); 
   return bullets; 
  }else{  //單倍火力 
   Bullet[] bullets = new Bullet[1]; 
   bullets[0] = new Bullet(x+2*xStep,y-yStep); 
   return bullets; 
  } 
 } 

 /** 移動 */ 
 @Override 
 public void step() { 
  if(images.length>0){ 
   image = images[index++/10%images.length]; //切換圖片hero0，hero1 
  } 
 } 

 /** 碰撞算法 */ 
 public boolean hit(FlyingObject other){ 

  int x1 = other.x - this.width/2;     //x坐標(biāo)最小距離 
  int x2 = other.x + this.width/2 + other.width; //x坐標(biāo)最大距離 
  int y1 = other.y - this.height/2;    //y坐標(biāo)最小距離 
  int y2 = other.y + this.height/2 + other.height; //y坐標(biāo)最大距離 

  int herox = this.x + this.width/2;    //英雄機(jī)x坐標(biāo)中心點(diǎn)距離 
  int heroy = this.y + this.height/2;    //英雄機(jī)y坐標(biāo)中心點(diǎn)距離 

  return herox>x1 && herox<x2 && heroy>y1 && heroy<y2; //區(qū)間范圍內(nèi)為撞上了 
 } 

}

import java.awt.Font; 
import java.awt.Color; 
import java.awt.Graphics; 
import java.awt.event.MouseAdapter; 
import java.awt.event.MouseEvent; 
import java.util.Arrays; 
import java.util.Random; 
import java.util.Timer; 
import java.util.TimerTask; 
import java.awt.image.BufferedImage; 

import javax.imageio.ImageIO; 
import javax.swing.ImageIcon; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
/**
 * Java學(xué)習(xí)交流QQ群：589809992 我們一起學(xué)Java！
 */
public class ShootGame extends JPanel { 
 public static final int WIDTH = 400; // 面板寬 
 public static final int HEIGHT = 654; // 面板高 
 /** 游戲的當(dāng)前狀態(tài): START RUNNING PAUSE GAME_OVER */ 
 private int state; 
 private static final int START = 0; 
 private static final int RUNNING = 1; 
 private static final int PAUSE = 2; 
 private static final int GAME_OVER = 3; 

 private int score = 0; // 得分 
 private Timer timer; // 定時器 
 private int intervel = 1000 / 100; // 時間間隔(毫秒) 

 public static BufferedImage background; 
 public static BufferedImage start; 
 public static BufferedImage airplane; 
 public static BufferedImage bee; 
 public static BufferedImage bullet; 
 public static BufferedImage hero0; 
 public static BufferedImage hero1; 
 public static BufferedImage pause; 
 public static BufferedImage gameover; 

 private FlyingObject[] flyings = {}; // 敵機(jī)數(shù)組 
 private Bullet[] bullets = {}; // 子彈數(shù)組 
 private Hero hero = new Hero(); // 英雄機(jī) 

 static { // 靜態(tài)代碼塊，初始化圖片資源 
  try { 
   background = ImageIO.read(ShootGame.class 
     .getResource("background.png")); 
   start = ImageIO.read(ShootGame.class.getResource("start.png")); 
   airplane = ImageIO 
     .read(ShootGame.class.getResource("airplane.png")); 
   bee = ImageIO.read(ShootGame.class.getResource("bee.png")); 
   bullet = ImageIO.read(ShootGame.class.getResource("bullet.png")); 
   hero0 = ImageIO.read(ShootGame.class.getResource("hero0.png")); 
   hero1 = ImageIO.read(ShootGame.class.getResource("hero1.png")); 
   pause = ImageIO.read(ShootGame.class.getResource("pause.png")); 
   gameover = ImageIO 
     .read(ShootGame.class.getResource("gameover.png")); 
  } catch (Exception e) { 
   e.printStackTrace(); 
  } 
 } 

 /** 畫 */ 
 @Override 
 public void paint(Graphics g) { 
  g.drawImage(background, 0, 0, null); // 畫背景圖 
  paintHero(g); // 畫英雄機(jī) 
  paintBullets(g); // 畫子彈 
  paintFlyingObjects(g); // 畫飛行物 
  paintScore(g); // 畫分?jǐn)?shù) 
  paintState(g); // 畫游戲狀態(tài) 
 } 

 /** 畫英雄機(jī) */ 
 public void paintHero(Graphics g) { 
  g.drawImage(hero.getImage(), hero.getX(), hero.getY(), null); 
 } 

 /** 畫子彈 */ 
 public void paintBullets(Graphics g) { 
  for (int i = 0; i < bullets.length; i++) { 
   Bullet b = bullets[i]; 
   g.drawImage(b.getImage(), b.getX() - b.getWidth() / 2, b.getY(), 
     null); 
  } 
 } 

 /** 畫飛行物 */ 
 public void paintFlyingObjects(Graphics g) { 
  for (int i = 0; i < flyings.length; i++) { 
   FlyingObject f = flyings[i]; 
   g.drawImage(f.getImage(), f.getX(), f.getY(), null); 
  } 
 } 

 /** 畫分?jǐn)?shù) */ 
 public void paintScore(Graphics g) { 
  int x = 10; // x坐標(biāo) 
  int y = 25; // y坐標(biāo) 
  Font font = new Font(Font.SANS_SERIF, Font.BOLD, 22); // 字體 
  g.setColor(new Color(0xFF0000)); 
  g.setFont(font); // 設(shè)置字體 
  g.drawString("SCORE:" + score, x, y); // 畫分?jǐn)?shù) 
  y=y+20; // y坐標(biāo)增20 
  g.drawString("LIFE:" + hero.getLife(), x, y); // 畫命 
 } 

 /** 畫游戲狀態(tài) */ 
 public void paintState(Graphics g) { 
  switch (state) { 
  case START: // 啟動狀態(tài) 
   g.drawImage(start, 0, 0, null); 
   break; 
  case PAUSE: // 暫停狀態(tài) 
   g.drawImage(pause, 0, 0, null); 
   break; 
  case GAME_OVER: // 游戲終止?fàn)顟B(tài) 
   g.drawImage(gameover, 0, 0, null); 
   break; 
  } 
 } 

 public static void main(String[] args) { 
  JFrame frame = new JFrame("Fly"); 
  ShootGame game = new ShootGame(); // 面板對象 
  frame.add(game); // 將面板添加到JFrame中 
  frame.setSize(WIDTH, HEIGHT); // 設(shè)置大小 
  frame.setAlwaysOnTop(true); // 設(shè)置其總在最上 
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 默認(rèn)關(guān)閉操作 
  frame.setIconImage(new ImageIcon("images/icon.jpg").getImage()); // 設(shè)置窗體的圖標(biāo) 
  frame.setLocationRelativeTo(null); // 設(shè)置窗體初始位置 
  frame.setVisible(true); // 盡快調(diào)用paint 

  game.action(); // 啟動執(zhí)行 
 } 

 /** 啟動執(zhí)行代碼 */ 
 public void action() { 
  // 鼠標(biāo)監(jiān)聽事件 
  MouseAdapter l = new MouseAdapter() { 
   @Override 
   public void mouseMoved(MouseEvent e) { // 鼠標(biāo)移動 
    if (state == RUNNING) { // 運(yùn)行狀態(tài)下移動英雄機(jī)--隨鼠標(biāo)位置 
     int x = e.getX(); 
     int y = e.getY(); 
     hero.moveTo(x, y); 
    } 
   } 

   @Override 
   public void mouseEntered(MouseEvent e) { // 鼠標(biāo)進(jìn)入 
    if (state == PAUSE) { // 暫停狀態(tài)下運(yùn)行 
     state = RUNNING; 
    } 
   } 

   @Override 
   public void mouseExited(MouseEvent e) { // 鼠標(biāo)退出 
    if (state == RUNNING) { // 游戲未結(jié)束，則設(shè)置其為暫停 
     state = PAUSE; 
    } 
   } 

   @Override 
   public void mouseClicked(MouseEvent e) { // 鼠標(biāo)點(diǎn)擊 
    switch (state) { 
    case START: 
     state = RUNNING; // 啟動狀態(tài)下運(yùn)行 
     break; 
    case GAME_OVER: // 游戲結(jié)束，清理現(xiàn)場 
     flyings = new FlyingObject[0]; // 清空飛行物 
     bullets = new Bullet[0]; // 清空子彈 
     hero = new Hero(); // 重新創(chuàng)建英雄機(jī) 
     score = 0; // 清空成績 
     state = START; // 狀態(tài)設(shè)置為啟動 
     break; 
    } 
   } 
  }; 
  this.addMouseListener(l); // 處理鼠標(biāo)點(diǎn)擊操作 
  this.addMouseMotionListener(l); // 處理鼠標(biāo)滑動操作 

  timer = new Timer(); // 主流程控制 
  timer.schedule(new TimerTask() { 
   @Override 
   public void run() { 
    if (state == RUNNING) { // 運(yùn)行狀態(tài) 
     enterAction(); // 飛行物入場 
     stepAction(); // 走一步 
     shootAction(); // 英雄機(jī)射擊 
     bangAction(); // 子彈打飛行物 
     outOfBoundsAction(); // 刪除越界飛行物及子彈 
     checkGameOverAction(); // 檢查游戲結(jié)束 
    } 
    repaint(); // 重繪，調(diào)用paint()方法 
   } 

  }, intervel, intervel); 
 } 

 int flyEnteredIndex = 0; // 飛行物入場計數(shù) 

 /** 飛行物入場 */ 
 public void enterAction() { 
  flyEnteredIndex++; 
  if (flyEnteredIndex % 40 == 0) { // 400毫秒生成一個飛行物--10*40 
   FlyingObject obj = nextOne(); // 隨機(jī)生成一個飛行物 
   flyings = Arrays.copyOf(flyings, flyings.length + 1); 
   flyings[flyings.length - 1] = obj; 
  } 
 } 

 /** 走一步 */ 
 public void stepAction() { 
  for (int i = 0; i < flyings.length; i++) { // 飛行物走一步 
   FlyingObject f = flyings[i]; 
   f.step(); 
  } 

  for (int i = 0; i < bullets.length; i++) { // 子彈走一步 
   Bullet b = bullets[i]; 
   b.step(); 
  } 
  hero.step(); // 英雄機(jī)走一步 
 } 

 /** 飛行物走一步 */ 
 public void flyingStepAction() { 
  for (int i = 0; i < flyings.length; i++) { 
   FlyingObject f = flyings[i]; 
   f.step(); 
  } 
 } 

 int shootIndex = 0; // 射擊計數(shù) 

 /** 射擊 */ 
 public void shootAction() { 
  shootIndex++; 
  if (shootIndex % 30 == 0) { // 300毫秒發(fā)一顆 
   Bullet[] bs = hero.shoot(); // 英雄打出子彈 
   bullets = Arrays.copyOf(bullets, bullets.length + bs.length); // 擴(kuò)容 
   System.arraycopy(bs, 0, bullets, bullets.length - bs.length, 
     bs.length); // 追加數(shù)組 
  } 
 } 

 /** 子彈與飛行物碰撞檢測 */ 
 public void bangAction() { 
  for (int i = 0; i < bullets.length; i++) { // 遍歷所有子彈 
   Bullet b = bullets[i]; 
   bang(b); // 子彈和飛行物之間的碰撞檢查 
  } 
 } 

 /** 刪除越界飛行物及子彈 */ 
 public void outOfBoundsAction() { 
  int index = 0; // 索引 
  FlyingObject[] flyingLives = new FlyingObject[flyings.length]; // 活著的飛行物 
  for (int i = 0; i < flyings.length; i++) { 
   FlyingObject f = flyings[i]; 
   if (!f.outOfBounds()) { 
    flyingLives[index++] = f; // 不越界的留著 
   } 
  } 
  flyings = Arrays.copyOf(flyingLives, index); // 將不越界的飛行物都留著 

  index = 0; // 索引重置為0 
  Bullet[] bulletLives = new Bullet[bullets.length]; 
  for (int i = 0; i < bullets.length; i++) { 
   Bullet b = bullets[i]; 
   if (!b.outOfBounds()) { 
    bulletLives[index++] = b; 
   } 
  } 
  bullets = Arrays.copyOf(bulletLives, index); // 將不越界的子彈留著 
 } 

 /** 檢查游戲結(jié)束 */ 
 public void checkGameOverAction() { 
  if (isGameOver()==true) { 
   state = GAME_OVER; // 改變狀態(tài) 
  } 
 } 

 /** 檢查游戲是否結(jié)束 */ 
 public boolean isGameOver() { 

  for (int i = 0; i < flyings.length; i++) { 
   int index = -1; 
   FlyingObject obj = flyings[i]; 
   if (hero.hit(obj)) { // 檢查英雄機(jī)與飛行物是否碰撞 
    hero.subtractLife(); // 減命 
    hero.setDoubleFire(0); // 雙倍火力解除 
    index = i; // 記錄碰上的飛行物索引 
   } 
   if (index != -1) { 
    FlyingObject t = flyings[index]; 
    flyings[index] = flyings[flyings.length - 1]; 
    flyings[flyings.length - 1] = t; // 碰上的與最后一個飛行物交換 

    flyings = Arrays.copyOf(flyings, flyings.length - 1); // 刪除碰上的飛行物 
   } 
  } 

  return hero.getLife() <= 0; 
 } 

 /** 子彈和飛行物之間的碰撞檢查 */ 
 public void bang(Bullet bullet) { 
  int index = -1; // 擊中的飛行物索引 
  for (int i = 0; i < flyings.length; i++) { 
   FlyingObject obj = flyings[i]; 
   if (obj.shootBy(bullet)) { // 判斷是否擊中 
    index = i; // 記錄被擊中的飛行物的索引 
    break; 
   } 
  } 
  if (index != -1) { // 有擊中的飛行物 
   FlyingObject one = flyings[index]; // 記錄被擊中的飛行物 

   FlyingObject temp = flyings[index]; // 被擊中的飛行物與最后一個飛行物交換 
   flyings[index] = flyings[flyings.length - 1]; 
   flyings[flyings.length - 1] = temp; 

   flyings = Arrays.copyOf(flyings, flyings.length - 1); // 刪除最后一個飛行物(即被擊中的) 

   // 檢查one的類型(敵人加分，獎勵獲取) 
   if (one instanceof Enemy) { // 檢查類型，是敵人，則加分 
    Enemy e = (Enemy) one; // 強(qiáng)制類型轉(zhuǎn)換 
    score += e.getScore(); // 加分 
   } else { // 若為獎勵，設(shè)置獎勵 
    Award a = (Award) one; 
    int type = a.getType(); // 獲取獎勵類型 
    switch (type) { 
    case Award.DOUBLE_FIRE: 
     hero.addDoubleFire(); // 設(shè)置雙倍火力 
     break; 
    case Award.LIFE: 
     hero.addLife(); // 設(shè)置加命 
     break; 
    } 
   } 
  } 
 } 

 /** 
  * 隨機(jī)生成飛行物 
  * 
  * @return 飛行物對象 
  */ 
 public static FlyingObject nextOne() { 
  Random random = new Random(); 
  int type = random.nextInt(20); // [0,20) 
  if (type < 4) { 
   return new Bee(); 
  } else { 
   return new Airplane(); 
  } 
 } 

}