JTable column spanning

Question

I am trying to make a JTable that has column spans available. Specifically, I am looking to nest a JTable inside another JTable, and w

Answer 1

Based on Code from Code-Guru:

/*
 *  (swing1.1beta3)
 * 
 * |-----------------------------------------------------|
 * |   1st  |      2nd    |      3rd         |
 * |-----------------------------------------------------|
 * |    |    |    |    |        |        |
 */
//package jp.gr.java_conf.tame.swing.examples;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;

import jp.gr.java_conf.tame.swing.table.*;

/**
 * @version 1.0 11/09/98
 */
public class MultiWidthHeaderExample extends JFrame {

  MultiWidthHeaderExample() {
    super( "Multi-Width Header Example" );

    DefaultTableModel dm = new DefaultTableModel();
    dm.setDataVector(new Object[][]{
      {"a","b","c","d","e","f"},
      {"A","B","C","D","E","F"}},
    new Object[]{"1 st","","","","",""});

    JTable table = new JTable( dm ) {
      protected JTableHeader createDefaultTableHeader() {
        return new GroupableTableHeader(columnModel);
      }
    };
    TableColumnModel cm = table.getColumnModel();
    ColumnGroup g_2nd = new ColumnGroup("2 nd");
    g_2nd.add(cm.getColumn(1));
    g_2nd.add(cm.getColumn(2));
    ColumnGroup g_3rd = new ColumnGroup("3 rd");
    g_3rd.add(cm.getColumn(3));
    g_3rd.add(cm.getColumn(4));
    g_3rd.add(cm.getColumn(5));
    GroupableTableHeader header = (GroupableTableHeader)table.getTableHeader();
    header.addColumnGroup(g_2nd);
    header.addColumnGroup(g_3rd);
    JScrollPane scroll = new JScrollPane( table );
    getContentPane().add( scroll );
    setSize( 400, 100 );  
    header.revalidate(); 
  }

  public static void main(String[] args) {
    MultiWidthHeaderExample frame = new MultiWidthHeaderExample();
    frame.addWindowListener( new WindowAdapter() {
      public void windowClosing( WindowEvent e ) {
        System.exit(0);
      }
    });
    frame.setVisible(true);
  }
}

Source: http://www.codeguru.com/java/articles/125.shtml (unavailable since 2012, see now in web archive)

Other ressources:

• Java-6 updated sources: http://qoofast.blog76.fc2.com/blog-entry-2.html (translated)
  • ColumnGroup.java
  • GroupableTableHeader.java
  • GroupableTableHeaderUI