Java 将图片设置为随机坐标？

所以我正在尝试写一个像飞鸟一样的硬币收集游戏，当我尝试将硬币图像坐标设置为随机数时，屏幕冻结。有什么帮助吗

这是我的球员级别：

package gamepackage;
import java.util.Random;

import org.newdawn.slick.*;
import org.newdawn.slick.geom.Rectangle;
import org.newdawn.slick.state.*;
public class Playing extends BasicGameState{
Image coin;
Image guy;
int coincounter = 0;
float x = 30, y = 90;
int coiny = 20, coinx= 1000;

public Playing(int state){


}

public void init(GameContainer gc, StateBasedGame sbg)throws SlickException{
    guy = new Image("res/PlaneMovie1.gif");
    coin = new Image("res/coin.gif");


}
public void render(GameContainer gc, StateBasedGame sbg, Graphics g)throws     SlickException{
    g.drawString("Coins:" + coincounter, 70, 70);
    g.drawImage(coin, coinx, coiny);
    g.drawImage(guy, x, y);
}
public void update(GameContainer gc, StateBasedGame sbg, int delta)throws SlickException{

Input input = gc.getInput();

coinx --;
if(input.isKeyDown(Input.KEY_SPACE)){   y -= 1 ; }
if(input.isKeyDown(Input.KEY_SPACE) == false){  y += .5;}
 if(y == coiny){ coincounter += 1;coinx = 1000; coiny -= 20;}
 if(coinx == -175){coinx = 1000; coiny += 20;}


}
public int getID(){
return 1;
}
}

---

你有跟踪记录吗？您是否插入了断点并使用调试器查看发生了什么？我没有看到您使用任何正在设置的随机坐标。。。