Help with JTable needed

Question

Hi guys. How to update a JTable? What am I doing wrong? When I press buttons nothing happend d:(
public void init() {
        this.setSize(640,420);
        //this.setLayout ( null );
        panel = new JPanel();
        //Builder.buildInsertGui();
        //Builder.buildInfoGui();
        //Builder.buildSettingsGui();
        Builder.table=Database.getOperations(); 
        ActionListener ladd = new ActionListener() {
               public void actionPerformed(ActionEvent e) {
                    Builder.table=new JTable();
                    System.out.println("free");
                    Application.panel.repaint();
          JButton badd = new JButton("Free");
          badd.addActionListener(ladd);
          ActionListener ldel = new ActionListener() {
               public void actionPerformed(ActionEvent e) {
                    Builder.table=Database.getOperations();
                    System.out.println("fill");
                    Application.panel.repaint();
          JButton bdel = new JButton("Fill");
          badd.addActionListener(ldel);
          this.panel.add(Builder.table);
          this.panel.add(bdel);
          this.panel.add(badd);
          this.add(panel);
   }

Answer 1

Hi,
first create the table once in the init method
second you don't need to call the repaint on the JPanel each time you do the action
third you need to update your table via the table Model by extending the AbstractTableModel
The table Model is the part which hold the data for the table to be presented
fourth get the table Model; then populate it again with different values
Fifth call table.repaint;
ex:
public class MyStocksTable extends JFrame {
  protected JTable m_table;
  protected StockTableData m_data;
  protected JLabel m_title;
  protected JButton m_btn;
  public MyStocksTable() {
    super("Stocks Table");
    setSize(600, 300);
     UIManager.put("Table.focusCellHighlightBorder",
          new LineBorder(Color.black, 0));
    m_data = new StockTableData();
    m_title = new JLabel(m_data.getTitle(),
      new ImageIcon("money.gif"), SwingConstants.CENTER); 
    m_title.setFont(new Font("Helvetica",Font.PLAIN,24));
    getContentPane().add(m_title, BorderLayout.NORTH);
    m_table = new JTable();
    m_table.setAutoCreateColumnsFromModel(false);
    m_table.setModel(m_data);
    m_btn = new JButton("UPDATE ME");
    getContentPane().add(m_btn,BorderLayout.SOUTH);
    m_btn.addActionListener(new MyActionListener(m_table));
    for (int k = 0; k < m_data.getColumnCount(); k++) {
      DefaultTableCellRenderer renderer = new
        DefaultTableCellRenderer();
      renderer.setHorizontalAlignment(
        StockTableData.m_columns[k].m_alignment);
      TableColumn column = new TableColumn(k,
      StockTableData.m_columns[k].m_width, renderer, null);
      m_table.addColumn(column);
    JTableHeader header = m_table.getTableHeader();
    header.setUpdateTableInRealTime(false);
    JScrollPane ps = new JScrollPane();
    ps.getViewport().setBackground(m_table.getBackground());
    ps.getViewport().add(m_table);
    getContentPane().add(ps, BorderLayout.CENTER);
  public static void main(String argv[]) {
     MyStocksTable frame = new MyStocksTable();
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     frame.setVisible(true);
class MyActionListener  implements ActionListener {
      private JTable table;
      public MyActionListener(JTable table){
           this.table = table;
      public void actionPerformed(ActionEvent e) {
      StockTableData dataModel = (StockTableData)table.getModel();
      dataModel.setDefaultData2();
      table.setModel(dataModel);
      table.repaint();
class StockData {
  public String  m_symbol;
  public String  m_name;
  public Double  m_last;
  public Double  m_open;
  public Double  m_change;
  public Double  m_changePr;
  public Long    m_volume;
  public StockData(String symbol, String name, double last,
   double open, double change, double changePr, long volume) {
    m_symbol = symbol;
    m_name = name;
    m_last = new Double(last);
    m_open = new Double(open);
    m_change = new Double(change);
    m_changePr = new Double(changePr);
    m_volume = new Long(volume);
class ColumnData {
  public String  m_title;
  public int     m_width;
  public int     m_alignment;
  public ColumnData(String title, int width, int alignment) {
    m_title = title;
    m_width = width;
    m_alignment = alignment;
class StockTableData extends AbstractTableModel {
  static final public ColumnData m_columns[] = {
    new ColumnData( "Symbol", 100, JLabel.LEFT ),
    new ColumnData( "Name", 160, JLabel.LEFT ),
    new ColumnData( "Last", 100, JLabel.RIGHT ),
    new ColumnData( "Open", 100, JLabel.RIGHT ),
    new ColumnData( "Change", 100, JLabel.RIGHT ),
    new ColumnData( "Change %", 100, JLabel.RIGHT ),
    new ColumnData( "Volume", 100, JLabel.RIGHT )
  protected SimpleDateFormat m_frm;
  protected Vector m_vector;
  protected Date   m_date;
  public StockTableData() {
    m_frm = new SimpleDateFormat("MM/dd/yyyy");
    m_vector = new Vector();
    setDefaultData();
  public void setDefaultData() {
    try {
      m_date = m_frm.parse("12/18/2004");
    catch (java.text.ParseException ex) {
      m_date = null;
    m_vector.removeAllElements();
    m_vector.addElement(new StockData("ORCL", "Oracle Corp.",
      23.6875, 25.375, -1.6875, -6.42, 24976600));
    m_vector.addElement(new StockData("EGGS", "Egghead.com",
      17.25, 17.4375, -0.1875, -1.43, 2146400));
    m_vector.addElement(new StockData("T", "AT&T",
      65.1875, 66, -0.8125, -0.10, 554000));
    m_vector.addElement(new StockData("LU", "Lucent Technology",
      64.625, 59.9375, 4.6875, 9.65, 29856300));
    m_vector.addElement(new StockData("FON", "Sprint",
      104.5625, 106.375, -1.8125, -1.82, 1135100));
    m_vector.addElement(new StockData("ENML", "Enamelon Inc.",
      4.875, 5, -0.125, 0, 35900));
    m_vector.addElement(new StockData("CPQ", "Compaq Computers",
      30.875, 31.25, -0.375, -2.18, 11853900));
    m_vector.addElement(new StockData("MSFT", "Microsoft Corp.",
      94.0625, 95.1875, -1.125, -0.92, 19836900));
    m_vector.addElement(new StockData("DELL", "Dell Computers",
      46.1875, 44.5, 1.6875, 6.24, 47310000));
    m_vector.addElement(new StockData("SUNW", "Sun Microsystems",
      140.625, 130.9375, 10, 10.625, 17734600));
    m_vector.addElement(new StockData("IBM", "Intl. Bus. Machines",
      183, 183.125, -0.125, -0.51, 4371400));
    m_vector.addElement(new StockData("HWP", "Hewlett-Packard",
      70, 71.0625, -1.4375, -2.01, 2410700));
    m_vector.addElement(new StockData("UIS", "Unisys Corp.",
      28.25, 29, -0.75, -2.59, 2576200));
    m_vector.addElement(new StockData("SNE", "Sony Corp.",
      96.1875, 95.625, 1.125, 1.18, 330600));
    m_vector.addElement(new StockData("NOVL", "Novell Inc.",
      24.0625, 24.375, -0.3125, -3.02, 6047900));
    m_vector.addElement(new StockData("HIT", "Hitachi, Ltd.",
      78.5, 77.625, 0.875, 1.12, 49400));
  public void setDefaultData2() {
         try {
           m_date = m_frm.parse("12/18/2004");
         catch (java.text.ParseException ex) {
           m_date = null;
         m_vector.removeAllElements();
         m_vector.addElement(new StockData("ORCLAlan", "Oracle Corp.",
           23.6875, 25.375, -1.6875, -6.42, 24976600));
         m_vector.addElement(new StockData("EGGSAlan", "Egghead.com",
           17.25, 17.4375, -0.1875, -1.43, 2146400));
         m_vector.addElement(new StockData("TAlan", "AT&T",
           65.1875, 66, -0.8125, -0.10, 554000));
         m_vector.addElement(new StockData("LU", "Lucent Technology",
           64.625, 59.9375, 4.6875, 9.65, 29856300));
  public int getRowCount() {
    return m_vector==null ? 0 : m_vector.size();
  public int getColumnCount() {
    return m_columns.length;
  public String getColumnName(int column) {
    return m_columns[column].m_title;
  public boolean isCellEditable(int nRow, int nCol) {
    return false;
  public Object getValueAt(int nRow, int nCol) {
    if (nRow < 0 || nRow>=getRowCount())
      return "";
    StockData row = (StockData)m_vector.elementAt(nRow);
    switch (nCol) {
      case 0: return row.m_symbol;
      case 1: return row.m_name;
      case 2: return row.m_last;
      case 3: return row.m_open;
      case 4: return row.m_change;
      case 5: return row.m_changePr;
      case 6: return row.m_volume;
    return "";
  public String getTitle() {
    if (m_date==null)
      return "Stock Quotes";
    return "Stock Quotes at "+m_frm.format(m_date);
}I hope this could help
Regard,
Alan Mehio
London,UK