Java DefaultTableModel


  • The first JTable created uses a two-dimensional object array to populate the row data and a String array to populate the column names.
  • The program shows that although you can get to the TableModel interface of the table model to get and set values for individual table cells created for this JTable , you cannot get to the DefaultTableModel in order to manipulate the data.
  • The second JTable is created by defining a DefaultTableModel with the data first. This allows the full range of actions by the table model to be performed on the JTable(e.g, adding a row, inserting a row, removing a row, adding a column, etc.).
  • You might also be interested in the AbstractTableModel class. This class allows you to create a custom table model for a JTable where you can store the data in anyway you like. It does not have to be in a Vector of Vectors.


import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.TableModel;
import javax.swing.table.DefaultTableModel;

public class TableExample {

    public static void main(String[] args) {
        //Use the event dispatch thread for Swing components
         EventQueue.invokeLater(new Runnable()
             public void run()
                 new TableExample().BuildGUI();         
    public void BuildGUI()
        JFrame guiFrame = new JFrame();
        //make sure the program exits when the frame closes
        guiFrame.setTitle("Creating a Table Example");
        //This will center the JFrame in the middle of the screen
        //Create a two dimensional array to hold the data for the JTable.
        Object[][] data = {{1,1,1},{2,2,2},{3,3,3},{4,4,4}};
        //A string array containing the column names for the JTable.
        String[] columnNames = {"Column 1","Column 2","Column 3"};
        //Create the JTable using the data array and column name array.
        JTable exampleJTable = new JTable(data, columnNames);
        //Create a JScrollPane to contain for the JTable
        JScrollPane sp = new JScrollPane(exampleJTable);
        //The JTable will provides methods which access the DefaultTabelModel.
        //created when the JTable object was created
        System.out.println(exampleJTable.getValueAt(2, 2));
        //The DefaultTableModel can be acessed through the getModel method.
        TableModel tabModel = exampleJTable.getModel();
        //Provides the same output as the exampleJTable.getValueAt method call
        System.out.println(tabModel.getValueAt(2, 2).toString());
        //Note: We can't cast the TableMode returned from the getModel method
        //to a DefaultTableModel object because it is implemented as an anonymous
        //inner class in the JTable. So let's create a JTable with a DefaultTableModel
        //we can use:
        //Create a DeafultTableModel object for another JTable
        DefaultTableModel defTableModel = new DefaultTableModel(data,columnNames);
        JTable anotherJTable = new JTable(defTableModel);
        //Create a JScrollPane to contain for the JTable
        JScrollPane anotherSP = new JScrollPane(anotherJTable);
        //an array holding data for a new column
        Object[] newData = {1,2,3,4};
        //Add a column
        defTableModel.addColumn("Column 4", newData);
        //an array holding data for a new row
        Object[] newRowData = {5,5,5,5};
        //Add a row
        //an array holding data for a new row
        Object[] insertRowData = {2.5,2.5,2.5,2.5};
        //Insert a row
        //Change a cell value
        defTableModel.setValueAt(8888, 3, 2);
        //Add the JScrollPanes to the JFrame.
        guiFrame.add(sp, BorderLayout.NORTH);
        guiFrame.add(anotherSP, BorderLayout.SOUTH);

Related Searches to DefaultTableModel