如何解决 "AWT-eventqueue-0"空指针异常

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.Thread;

public class MoveTest extends JFrame{
	Graphics paneldraw;
	Image image=new ImageIcon("D:/Images/hj.png").getImage();
	Image panel=this.createImage(400,300);
	static int x;
	Thread t;
	public MoveTest(){
		this.setTitle("giao");
		this.setLayout(null);
    this.setVisible(true);
    this.setSize(400,300);
    this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
	}
	public void paint(Graphics g){
		System.out.println("1");
		paneldraw=panel.getGraphics();
		paneldraw.fillRect(0,0,1500,1500);
		paneldraw.drawImage(image,x,100,this);
		Graphics2D g2=(Graphics2D)g;
		g2.drawImage(panel,x,100,this);
		x+=2;
	}
	public void doIt(){
		PaintGo p=new PaintGo();
		p.start();
	}
	class PaintGo extends Thread{
			public void run(){
				try{
					for(int i=0;i<1000;i++){
				    repaint();
            sleep(100);
			    }
				}catch(InterruptedException e){
					e.printStackTrace();
				}
		  }		
	}
	public static void main(String[] args){
		new MoveTest().doIt();
	}
}

就是没有看到什么空指针，晕。

高手解决一下好吗 

我giao