Viredus

What is wrong with this code? I'm trying to make a two-dimensional JLabel array and setting it up in a GUI using GridBagConstraints. I have a array traversal loop setting image icons to each space, but I keep reaching a NullPointerException. Any input would be helpful.

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.Image.*;
import java.awt.Toolkit;
import javax.swing.Timer.*;

public class Grid
{
public JFrame window = new JFrame();
public JPanel setup = new JPanel();
public JLabel[][] grid = new JLabel[5][5];
public Toolkit tk = window.getToolkit();
public Image emptySpace = tk.createImage("grid.gif");
public ImageIcon image1 = new ImageIcon(emptySpace.getScaledInstance(200, 200, 0));

public Grid()
{
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setSize(new Dimension(150, 300));
setup.setLayout(new GridBagLayout());

GridBagConstraints gbc = new GridBagConstraints();
for (int row=0; row < grid.length; row++){
for (int col=0; col < grid[row].length; col++)
{
grid[row][col].setIcon(image1);
}
}
for (int row=0; row < grid.length; row++) {
for (int col=0; col < grid[row].length; col++)
{
setup.add(grid[row][col], gbc);
}
}

window.getContentPane().add(setup);
window.setSize(100,400);
window.setVisible(true);

}

public static void createAndShowGUI()
{

Grid gridProg = new Grid();


}

public static void main(String[] args)
{



createAndShowGUI();
}

}

Polyphemus_

We would love it if you would use code tags, an appropiate thread title, and gave a little more info about your code: where does what happen, where does the error occur and what message do you get.

Viredus

Sorry.
Exception in thread "main" java.lang.NullPointerException
at Grid<init><Grid.java>
at Grid.createandshowGUI<Grid.java>
at Grid.main<Grid.java>

Viredus

jaeusm

Each element in your grid array is null. Put something in it.