新手求教-工具类调用的问题

[Umbrellat]

package com.tty.game;
 
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
 
public class GameUtil {
    // 工具类最好将构造器私有化。
    private GameUtil() {
    	
    } 
 
    public static Image getImage(String path) {
        BufferedImage bi = null;
        try {
            URL u = GameUtil.class.getClassLoader().getResource(path);
            bi = ImageIO.read(u);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return bi;
    }
}

package com.tty.game;

import javax.swing.JFrame;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

/**
 * 飞机小游戏的主窗口
 * @author tty
 *
 */
public class MyGameFrame extends JFrame{
	
	//将背景图片与飞机图片定义为成员变量
    Image bgImg = GameUtil.getImage("images/bg.jpg");
    Image planeImg = GameUtil.getImage("images/plane.png");

求教为什么后面GameUtil这个工具类无法调用