关于两个类绘制图片的问题

import javax.swing.JFrame;



import java.awt.Canvas;

import java.awt.Graphics;

import java.awt.Image;

import java.awt.Toolkit;







public class Fish extends JFrame{

	

	private static Toolkit tk = Toolkit.getDefaultToolkit();

	private static Image  img; 

	 	

	static{img = tk.getImage(Fish.class.getClassLoader().getResource("images/1.jpg"));}

	

	public Fish() {

		this.setSize(440,300);

		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		add(new CanvasPanel());

	}

	public void draw(Graphics g) {

		g.drawImage(img,0,0,this);

	}

}