swing在java中显示图像，未找到主类

Question

我设置了以下代码，以便在硬盘上显示图像。然而，每当我运行代码时，就会出现以下错误

import java.awt.*;  
import java.awt.Graphics.*;  
import java.awt.event.*;  
import java.awt.image.*;  
import java.io.*;  
import javax.imageio.*;  
import javax.swing.*;  
import javax.swing.JFrame;  
  
  
public class ImagePanel extends JPanel{  
  
    public ImagePanel() {  
      setTitle("ImagePanel");  
      setSize(500,250);  
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
      setVisible(true);  
    public void (Graphics g){  
      Image image = new ImageIcon("C:\\Users\\Public\\Pictures\\Sample Pictures\\Desert.jpg")).getImage();  
      g.drawImage(image,3,4, this);  
    }  
   
public static void main(String[] args) {  
  ImagePanel img = new ImagePanel();  
}  
} 

我得到的错误是：

<No main classes found>