Java程序冻结没有错误

Question

我正在制作游戏，我的java程序会毫无错误地冻结。 我为我的对象做了一个Trail，所以看起来很酷。如果没有Trail，它就像魅力一样，但当我将Trail添加到对象时，它的工作时间为2-3秒，并冻结。

package myfirstgame;

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;



public class Trail extends GameObject{

    private float alpha = 1;
    private Handler handler;
    private Color color;
    private int width, height;
    private float life;

    public Trail(int x, int y, ID id, Color color, int width, int height, float life,Handler handler) {
        super(x, y, id);
        this.handler = handler;
        this.color = color;
        this.width = width;
        this.height = height;
        this.life = life;
    }


    public void tick() {
        if(alpha > life){
            alpha -= (life - 0.0001f);
        }else {
            handler.removeObject(this);
        }
    }


    public void render(Graphics g) {
        Graphics2D g2d = (Graphics2D) g;
        g2d.setComposite(makeTransparent(alpha));
        g.setColor(color);
        g.fillRect(x, y, width, height);

        g2d.setComposite(makeTransparent(1));

    }

    private AlphaComposite makeTransparent(float alpha){
        int type = AlphaComposite.SRC_OVER;

        return(AlphaComposite.getInstance(type, alpha));
    }


    public Rectangle getBounds() {

        return null;
    }

}

然后在我的Game.java中我有这个：

handler.addObject(new BasicEnemy(r.nextInt(WIDTH), r.nextInt(HEIGHT),ID.BasicEnemy, handler));

在我的BasicEnemy.java中：

handler.addObject(new Trail(x, y, ID.Trail, Color.red, 16,16, 0.01f, handler));