java多球运动_Java线程（实现多线程小球运动）

好的，我可以帮你解答这个问题。

实现多线程小球运动需要以下步骤：

1. 创建小球类 Ball，并实现 Runnable 接口

public class Ball implements Runnable{
    private int x;
    private int y;
    private int r;
    private int vx;
    private int vy;
    private Color color;
    private Component component;

    public Ball(Component component, int x, int y, int r, int vx, int vy, Color color){
        this.component = component;
        this.x = x;
        this.y = y;
        this.r = r;
        this.vx = vx;
        this.vy = vy;
        this.color = color;
    }

    public void run(){
        while (true){
            //更新小球位置
            x += vx;
            y += vy;

            //检查小球是否碰到边界
            if (x - r < 0){
                vx = -vx;
                x = r;
            }
            else if (x + r > component.getWidth()){
                vx = -vx;
                x = component.getWidth() - r;
            }

            if (y - r < 0){
                vy = -vy;
                y = r;
            }
            else if (y + r > component.getHeight()){
                vy = -vy;
                y = component.getHeight() - r;
            }

            //绘制小球
            component.repaint();

            try{
                Thread.sleep(10);
            }
            catch (InterruptedException e){
                e.printStackTrace();
            }
        }
    }

    //绘制小球
    public void draw(Graphics g){
        g.setColor(color);
        g.fillOval(x - r, y - r, 2 * r, 2 * r);
    }
}

2. 在主函数中创建多个小球，并启动线程

public static void main(String[] args){
    JFrame frame = new JFrame();
    frame.setSize(400, 400);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);

    JPanel panel = new JPanel(){
        protected void paintComponent(Graphics g){
            super.paintComponent(g);
            for (Ball ball : balls){
                ball.draw(g);
            }
        }
    };
    frame.add(panel);

    Ball[] balls = new Ball[10];
    for (int i = 0; i < balls.length; i++){
        int x = (int)(Math.random() * 300 + 50);
        int y = (int)(Math.random() * 300 + 50);
        int r = (int)(Math.random() * 20 + 10);
        int vx = (int)(Math.random() * 10 - 5);
        int vy = (int)(Math.random() * 10 - 5);
        Color color = new Color((int)(Math.random() * 255), (int)(Math.random() * 255), (int)(Math.random() * 255));
        balls[i] = new Ball(panel, x, y, r, vx, vy, color);
        new Thread(balls[i]).start();
    }
}

通过以上步骤，我们就可以实现多个小球在窗口中运动了。