/* (swing1.1) (swing#1356,#1454) */package tame.examples;import java.awt.BorderLayout;import java.awt.Component;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JScrollPane;import javax.swing.JTable;import javax.swing.JViewport;import javax.swing.UIManager;import javax.swing.table.DefaultTableModel;import javax.swing.table.JTableHeader;import javax.swing.table.TableCellRenderer;import tame.table.AttributiveCellTableModel;import tame.table.CellSpan;import tame.table.MultiSpanCellTable;/**<pre> *   ---------------------------------------------- *  |         SNo.        | *   ---------------------------------------------- *  |          |     1    | *  |   Name   |----------------------------------- *  |          |     2    | *   ---------------------------------------------- *  |          |     1    | *  |          |----------------------------------- *  | Language |     2    | *  |          |----------------------------------- *  |          |     3    | *   ----------------------------------------------..Exception in thread "main" java.lang.NullPointerException        at javax.swing.table.DefaultTableModel.getColumnCount(DefaultTableModel.java:575)        at javax.swing.table.DefaultTableModel.justifyRows(DefaultTableModel.java:242)        at javax.swing.table.DefaultTableModel.newRowsAdded(DefaultTableModel.java:262)        at tame.table.AttributiveCellTableModel.setDataVector(AttributiveCellTableModel.java:65)</pre>@author Nobuo Tamemasa@version 1.0 03/06/99*/public class MultipleRowHeaderExample extends JFrame {  Object[][] data;  Object[] column;  JTable table;  MultiSpanCellTable fixedTable;  public MultipleRowHeaderExample() {    super( "Multiple Row Header Example" );    setSize( 400, 150 );    data =  new Object[][]{        {"SNo."    ,"" },        {"Name"    ,"1"},        {""        ,"2"},        {"Language","1"},        {""        ,"2"},        {""        ,"3"}};    column = new Object[]{"",""};    AttributiveCellTableModel fixedModel = new AttributiveCellTableModel(data, column) {      public boolean CellEditable(int row, int col) {        return false;      }    };    CellSpan cellAtt =(CellSpan)fixedModel.getCellAttribute();    cellAtt.combine(new int[] {0}    ,new int[] {0,1});    cellAtt.combine(new int[] {1,2}  ,new int[] {0});    cellAtt.combine(new int[] {3,4,5},new int[] {0});    DefaultTableModel    model = new DefaultTableModel(data.length, 3);    fixedTable = new MultiSpanCellTable( fixedModel );    table = new JTable( model );    fixedTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);    fixedTable.setDefaultRenderer(Object.class, new RowHeaderRenderer(fixedTable));    fixedTable.setGridColor(table.getTableHeader().getBackground());    JScrollPane scroll = new JScrollPane( table );    JViewport viewport = new JViewport();    viewport.setView(fixedTable);    viewport.setPreferredSize(fixedTable.getPreferredSize());    scroll.setRowHeaderView(viewport);    getContentPane().add(scroll, BorderLayout.CENTER);  }  public static void main(String[] args) {    MultipleRowHeaderExample frame = new MultipleRowHeaderExample();    frame.addWindowListener( new WindowAdapter() {      public void windowClosing( WindowEvent e ) {	System.exit(0);      }    });    frame.setVisible(true);  }  class RowHeaderRenderer extends JLabel implements TableCellRenderer {    RowHeaderRenderer(JTable table) {      JTableHeader header = table.getTableHeader();      setOpaque(true);      setBorder(UIManager.getBorder("TableHeader.cellBorder"));      setHorizontalAlignment(CENTER);      setForeground(header.getForeground());      setBackground(header.getBackground());      setFont(header.getFont());    }    public Component getTableCellRendererComponent(JTable table, Object value,                          boolean isSelected, boolean hasFocus, int row, int column) {      setText((value == null) ? "" : value.toString());      return this;    }  }}