Jtable:Is Nested header Possible

Question

How to give nested header in java swing . I have defined the 4 main headers (type,source ,target ,default) wanted to have subheaders under each main header.
Example Code:
private String[] tableHeaders = new String[] {
               type,source ,target ,default};
private Vector<Vector<Object>> Vector = new Vector<Vector<Object>>();
private Vector<Object> headers = new Vector<Object>(
               Arrays.asList(tableHeaders));
private DefaultTableModel defaultTableModel = new DefaultTableModel(Vector,
               headers) {
          private static final long serialVersionUID = 1L;
          boolean[] columnEditables = new boolean[] { false, false, false, false };
          public boolean isCellEditable(int row, int column) {
               return columnEditables[column];
          public boolean isRowSelected(int row) {
               return true;
     };

Answer 1

I have worked on something similar. Here is one possible solution that you may want to try which is based on creating two tables - one main table and one inner table. Inner table is rendered as a column of the main table. You have to handle the table cell renderer and editor for the main table so that it can render inner table and allow normal table editing. I have added just one inner table in the code below but you can add more as per your requirement for showing them in other columns of the main table.
import java.awt.Component;     
import javax.swing.AbstractCellEditor; 
import javax.swing.JCheckBox;
import javax.swing.JFrame; 
import javax.swing.JScrollPane; 
import javax.swing.JTable; 
import javax.swing.table.DefaultTableCellRenderer;      
import javax.swing.table.DefaultTableModel; 
import javax.swing.table.TableCellEditor; 
import javax.swing.table.TableColumn; 
import javax.swing.table.TableColumnModel;
public class NestedJTableHeader extends JFrame { 
        private JTable mainTable; 
        private JTable innerTable; 
        private Object[][] tableList;        
        private String[] columnNames = {"A", "B", "C", "D", "E"}; 
        private Object[][] data = { 
                {"1", "2", "3", "4", new Boolean(false)}, 
                {"5", "6", "7", "8", new Boolean(true)}, 
                {"9", "10", "11", "12", new Boolean(false)}, 
                {"13", "14", "15", "16", new Boolean(true)}, 
                {"17", "18", "19", "20", new Boolean(false)} 
        private String[] names = {"Type", "Source", "Target", "Default"};
        public NestedJTableHeader(){            
            innerTable = new JTable(new DefaultTableModel (data, columnNames){
                    public Class<?> getColumnClass(int columnIndex) {
                         if(columnIndex==4)
                              return Boolean.class;
                         else
                              return super.getColumnClass(columnIndex);
            tableList = new Object[1][]; 
            tableList[0] = new Object[1]; 
            tableList[0][0] = innerTable; 
            mainTable = new JTable(new DefaultTableModel(tableList, names)); 
            TableColumn tc = mainTable.getColumnModel().getColumn(0); 
            tc.setCellRenderer(new CustomTableCellRenderer(innerTable)); 
            tc.setCellEditor(new CustomTableCellEditor(innerTable)); 
            tc = mainTable.getColumnModel().getColumn(1); 
            mainTable.setRowHeight(innerTable.getPreferredSize().height+innerTable.getTableHeader().getPreferredSize().height+4); 
            // Enable the ability to select a single cell  
            mainTable.setColumnSelectionAllowed(true);  
            mainTable.setRowSelectionAllowed(true);  
            this.getContentPane().add(new JScrollPane(mainTable)); 
            this.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 
            this.pack();
            setSize(600,450);
            setVisible(true); 
        class CustomTableCellRenderer extends DefaultTableCellRenderer { 
            JTable table; 
            CustomTableCellRenderer(JTable table){ 
                this.table=table; 
                this.table.setOpaque(true); 
                this.table.setAlignmentY(JTable.LEFT_ALIGNMENT); 
            @Override 
            public Component getTableCellRendererComponent(JTable table, Object value, 
                    boolean isSelected, boolean hasFocus, int row, int column) { 
                this.table=(JTable)value; 
                return new JScrollPane(this.table);  
        class CustomTableCellEditor extends AbstractCellEditor implements TableCellEditor{ 
            JTable table; 
            CustomTableCellEditor(JTable table){ 
                this.table=table; 
                this.table.setOpaque(true); 
                this.table.setAlignmentY(JTable.LEFT_ALIGNMENT); 
            @Override 
            public Component getTableCellEditorComponent(JTable table, 
                    Object value, boolean isSelected, int row, int column) { 
                this.table=(JTable)value; 
                return new JScrollPane(this.table); 
            @Override 
            public Object getCellEditorValue() { 
                return this.table; 
         * @param args
        public static void main(String[] args) { 
            new NestedJTableHeader(); 
} Edited by: Nitin Khare on May 17, 2012 12:42 AM