Java – why doesn’t my JFrame display?

I'm trying to display a solved Sudoku puzzle in a window with 81 boxes I did this:

import java.awt.GridLayout;
import java.awt.*;

import javax.swing.JFrame;
import javax.swing.JLabel;


public class GraphicSolver extends JFrame {

GraphicSolver(int[][] spelplan) {

    Panel panel = new Panel(new GridLayout(9,9));

    for(int i=9;i<9;i++){
        for(int x=0;x<9;x++){
            panel.add(new JLabel(""+spelplan[i][x]));
        }
    }

    Frame frame = new Frame();
    frame.add(panel);


    frame.setVisible(true);

}
}

However, it only gives me an empty window without any numbers I would be happy if someone could point me in the right direction

Solution

The external circulation shall start from zero:

for(int i=0;i<9;i++){