窗口类:package Shiyan;
import javax.swing.*;
public class chuangkou {
    public chuangkou(){
        super();
        setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT);
         ((Object) getContentPane()).add(new Mypane1());
    }
    private void setSize(int defaultWidth, int defaultHeight) {
        // TODO Auto-generated method stub
        
    }
    private Object getContentPane() {
        // TODO Auto-generated method stub
        return null;
    }
    public static final int DEFAULT_WIDTH=300;
    public static final int DEFAULT_HEIGHT=300;
    public void setVisible(boolean b) {
        // TODO Auto-generated method stub
        
    }
    public void setDefaultCloseOperation(int exitOnClose) {
        // TODO Auto-generated method stub
        
    }
}
内函数:
package Shiyan;
import java.awt.*;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.*;
public class Mypane1 {
    public static final int DEFAULT_WIDTH=300;
    public static final int DEFAULT_HEIGHT=300;
    
    public Mypane1(){
        setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT);
    }
    private void setSize(int defaultWidth, int defaultHeight) {
        // TODO Auto-generated method stub
        
    }
    protected void paintComponent(Graphics g){
        super.paintComponent(g);
        Graphics2D g2=(Graphics2D)g;
        
        
        Font font=new Font("黑体",Font.PLAIN,16);
        g2.setFont(font);
        g2.drawString("1
  2
  3
  4
  5
  6
  7
  8
  9",DEFAULT_WIDTH/2-100,60);
        g2.drawString("=====================",DEFAULT_WIDTH/2-130,76);
        for(int i=1;i<10;i++){
            g2.drawString(new Integer(i).toString(),DEFAULT_WIDTH/2-126,76+i*18);
            for(int j=1;j<10;j++){
                g2.drawString(new Integer(i*j).toString(),DEFAULT_WIDTH/2-122+j*24,76+i*18);
            }
        }
                
    }
}
运行类:
package Shiyan;
import javax.swing.JFrame;
public class test {
     public static void main(String[] ages){
         chuangkou frame=new chuangkou();
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
     }
}