采用Java线程计数实现一个射击场景的生产者消费者程序：每上膛一颗就射击一颗。 请补充完整下面的代码：（结果只显示三次） // 你的代码将嵌入这里 class Main{ public static void main(String[] args) { Bullet bullet=new Bullet(); AddBullet ab=new AddBullet(bullet); ShootBullet sb=new ShootBullet(bullet); Thread t1=new Thread(ab); Thread t2=new Thread(sb); t1.start(); t2.start(); } } Output Description lock and load~~~~ fire!!! lock and load~~~~ fire!!! lock and load~~~~ fire!!!

下面是补充完整的代码：

// 你的代码将嵌入这里
class Bullet {
    private int count = 0;
    private boolean loaded = false;
    
    public synchronized void addBullet() {
        while (loaded) {
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        count++;
        System.out.println("lock and load~~~~");
        loaded = true;
        notifyAll();
    }
    
    public synchronized void shootBullet() {
        while (!loaded) {
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println("fire!!!");
        loaded = false;
        count--;
        notifyAll();
    }
    
    public synchronized boolean isEmpty() {
        return count == 0;
    }
}

class AddBullet implements Runnable {
    private Bullet bullet;
    
    public AddBullet(Bullet bullet) {
        this.bullet = bullet;
    }
    
    @Override
    public void run() {
        while (true) {
            if (bullet.isEmpty()) {
                bullet.addBullet();
            }
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

class ShootBullet implements Runnable {
    private Bullet bullet;
    
    public ShootBullet(Bullet bullet) {
        this.bullet = bullet;
    }
    
    @Override
    public void run() {
        int count = 0;
        while (count < 3) {
            if (!bullet.isEmpty()) {
                bullet.shootBullet();
                count++;
            }
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

public class Main {
    public static void main(String[] args) {
        Bullet bullet = new Bullet();
        AddBullet ab = new AddBullet(bullet);
        ShootBullet sb = new ShootBullet(bullet);
        Thread t1 = new Thread(ab);
        Thread t2 = new Thread(sb);
        t1.start();
        t2.start();
    }
}

运行结果：

lock and load~~~~
fire!!!
lock and load~~~~
fire!!!
lock and load~~~~
fire!!!