JTable is not inserting the data

[Maheswaran Devaraj]

Hi All,

I tried to insert to the value into the JTable, But I couldn't do it, Help me to resolve this.

 
      package elect.pmrsoft.gui;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import java.awt.Dimension;
import java.awt.GridLayout;

/**
 * TableDemo is just like SimpleTableDemo, except that it uses a custom
 * TableModel.
 */
public class TableDemo extends JPanel {
  private boolean DEBUG = false;

  public TableDemo() {
    super(new GridLayout(1, 0));

    JTable table = new JTable(new MyTableModel());
    MyTableModel tablemodel = new MyTableModel();
    tablemodel.setValueAt("Anuuthayam", 1, 0);
    tablemodel.setValueAt("Pon Uthayam", 1, 1);
    tablemodel.setValueAt("Tennis", 1, 2);
    tablemodel.setValueAt("10", 1, 3);
    tablemodel.setValueAt(false, 1, 4);
    //tablemodel.setValueAt("Anuuthayam", 5, 0);
    table.setPreferredScrollableViewportSize(new Dimension(500, 70));

    //Create the scroll pane and add the table to it.
    JScrollPane scrollPane = new JScrollPane(table);

    //Add the scroll pane to this panel.
    add(scrollPane);
  }

  class MyTableModel extends AbstractTableModel {
    private String[] columnNames = { "First Name", "Last Name", "Sport",
        "# of Years", "Vegetarian" };

   /* private Object[][] data = {
        { "Mary", "Campione", "Snowboarding", new Integer(5),
            new Boolean(false) },
        { "Alison", "Huml", "Rowing", new Integer(3), new Boolean(true) },
        { "Kathy", "Walrath", "Knitting", new Integer(2),
            new Boolean(false) },
        { "Sharon", "Zakhour", "Speed reading", new Integer(20),
            new Boolean(true) },
        { "Philip", "Milne", "Pool", new Integer(10),
            new Boolean(false) } };*/

    public int getColumnCount() {
      return columnNames.length;
    }

    public int getRowCount() {
      //return data.length;
    	return 0;
    }

    public String getColumnName(int col) {
      return columnNames[col];
    }

    public Object getValueAt(int row, int col) {
      //return data[row][col];
    	return 0;
    }

    /*
     * JTable uses this method to determine the default renderer/ editor for
     * each cell. If we didn't implement this method, then the last column
     * would contain text ("true"/"false"), rather than a check box.
     */
    public Class getColumnClass(int c) {
      return getValueAt(0, c).getClass();
    }

    /*
     * Don't need to implement this method unless your table's editable.
     */
    public boolean isCellEditable(int row, int col) {
      //Note that the data/cell address is constant,
      //no matter where the cell appears onscreen.
      if (col < 2) {
        return false;
      } else {
        return true;
      }
    }

    /*
     * Don't need to implement this method unless your table's data can
     * change.
     */
    public void setValueAt(Object value, int row, int col) {
      if (DEBUG) {
        System.out.println("Setting value at " + row + "," + col
            + " to " + value + " (an instance of "
            + value.getClass() + ")");
      }
      System.out.println(value);
      super.setValueAt(value, row, col);
      //data[row][col] = value;
     // System.out.println(data[row][col]);
      
      fireTableCellUpdated(row, col);

      if (DEBUG) {
        System.out.println("New value of data:");
        printDebugData();
      }
    }

    private void printDebugData() {
      int numRows = getRowCount();
      int numCols = getColumnCount();

      for (int i = 0; i < numRows; i++) {
        System.out.print("    row " + i + ":");
        for (int j = 0; j < numCols; j++) {
          //System.out.print("  " + data[i][j]);
        }
        System.out.println();
      }
      System.out.println("--------------------------");
    }
  }

  /**
   * Create the GUI and show it. For thread safety, this method should be
   * invoked from the event-dispatching thread.
   */
  private static void createAndShowGUI() {
    //Make sure we have nice window decorations.
    JFrame.setDefaultLookAndFeelDecorated(true);

    //Create and set up the window.
    JFrame frame = new JFrame("TableDemo");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    //Create and set up the content pane.
    TableDemo newContentPane = new TableDemo();
    newContentPane.setOpaque(true); //content panes must be opaque
    frame.setContentPane(newContentPane);

    //Display the window.
    frame.pack();
    frame.setVisible(true);
  }

  public static void main(String[] args) {
    //Schedule a job for the event-dispatching thread:
    //creating and showing this application's GUI.
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        createAndShowGUI();
      }
    });
  }
}

   

Thanks and Regards,
Mahes

[Rob Spoor]

Maheswaran Devaraj wrote:

    public int getRowCount() {
      //return data.length;
    	return 0;
    } 

The return of that method determines how many rows will be displayed. You will need to return something other than 0.
If you want to be able to add data, an Object[][] is a bad idea. A List<Object[]> will be a better idea; it will allow you to add rows (being Object[] instances). Also, use the fireXXX methods of AbstractTableModel after something has changed in your model, or you won't see the changes.