jTable Header Problem

[Anand Karia]

Hi All.

How can i create table headers at run time.

i created table with 4 columns namely (A,B,C,D).
At runtime on a single button click, i want to chage the header from above to (R,S,T,U).

Can any1 help me?

Anand

[Craig Wood]

import java.awt.*;
import java.awt.event.*;
import java.util.Random;
import javax.swing.*;
import javax.swing.table.*;
 
public class ChangingHeaders
{
    JTable table;
    Random seed;
 
    public ChangingHeaders()
    {
        seed = new Random();
        JButton change = new JButton("change");
        change.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                changeHeaders();
            }
        });
        JPanel north = new JPanel();
        north.add(change);
        String[] headers = { "A", "B", "C", "D" };
        int rows = 4;
        int cols = 4;
        String[][] data = new String[rows][cols];
        for(int j = 0; j < rows; j++)
            for(int k = 0; k < cols; k++)
                data[j][k] = "item " + (j * cols + k + 1);
        table = new JTable(data, headers);
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(north, "North");
        f.getContentPane().add(new JScrollPane(table));
        f.setSize(300,200);
        f.setLocation(200,200);
        f.setVisible(true);
    }
 
    private void changeHeaders()
    {
        TableColumnModel model = table.getTableHeader().getColumnModel();
        for(int j = 0; j < model.getColumnCount(); j++)
        {
            TableColumn col = model.getColumn(j);
            col.setHeaderValue(getRandomValue());
        }
        table.getTableHeader().repaint();
    }
 
    private String getRandomValue()
    {
        String s = "";
        String letters = "abcdefghijklmnopqrstuvwxyz";
        int index = seed.nextInt(letters.length());
        if(index == letters.length() - 1)
            s = letters.substring(index);
        else
            s = letters.substring(index, index + 1);
        return s.toUpperCase();
    }
 
    public static void main(String[] args)
    {
        new ChangingHeaders();
    }
}