Java examples on Java Swing

How do I programmatically select JTable's columns?

This program shows you how to select some columns in the JTable programmatically. Below we demonstrates how to select columns using the setColumnSelectionInterval() method, remove or clear column selection using removeColumnSelectionInterval() method and use the addColumnSelectionInterval() to add more columns to the previously selected columns.

package org.kodejava.example.swing;

import javax.swing.*;
import javax.swing.table.AbstractTableModel;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class JTableColumnSelectProgramatically extends JPanel {
    public JTableColumnSelectProgramatically() {
        initializePanel();
    }

    private void initializePanel() {
        setLayout(new BorderLayout());
        setPreferredSize(new Dimension(475, 150));

        final JTable table = new JTable(new MyTableModel());
        table.setFillsViewportHeight(true);
        JScrollPane pane = new JScrollPane(table);

        JLabel label1 = new JLabel("From col: ");
        final JTextField field1 = new JTextField(3);
        JLabel label2 = new JLabel("To col: ");
        final JTextField field2 = new JTextField(3);
        JButton select = new JButton("Select");
        JButton clear = new JButton("Clear");
        JButton add = new JButton("Add another one");

        //
        // Enables column selection mode and disable row
        // selection mode.
        //
        table.setColumnSelectionAllowed(true);
        table.setRowSelectionAllowed(false);

        //
        // Select columns based on the input.
        //
        select.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent event) {
                int index1 = 0;
                int index2 = 0;
                try {
                    index1 = Integer.valueOf(field1.getText());
                    index2 = Integer.valueOf(field2.getText());
                } catch (NumberFormatException e) {
                    e.printStackTrace();
                }

                if (index1 < 0 || index2 < 0 ||
                        index1 >= table.getColumnCount() ||
                        index2 >= table.getColumnCount()) {
                    JOptionPane.showMessageDialog(table, "Selection out of range!");
                } else {
                    table.setColumnSelectionInterval(index1, index2);
                }
            }
        });

        //
        // Clears column selection
        //
        clear.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                table.removeColumnSelectionInterval(0, table.getColumnCount() - 1);
                field1.setText("");
                field2.setText("");
            }
        });

        //
        // Add one more column after the last selected column.
        //
        add.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent event) {
                int index2 = 0;
                try {
                    index2 = Integer.valueOf(field2.getText());
                } catch (NumberFormatException e) {
                    e.printStackTrace();
                }

                index2 = index2 + 1;
                table.addColumnSelectionInterval(index2, index2);
                field2.setText(String.valueOf(index2));
            }
        });

        JPanel command = new JPanel(new FlowLayout());
        command.add(label1);
        command.add(field1);
        command.add(label2);
        command.add(field2);
        command.add(select);
        command.add(clear);
        command.add(add);

        add(pane, BorderLayout.CENTER);
        add(command, BorderLayout.SOUTH);
    }

    public static void showFrame() {
        JPanel panel = new JTableColumnSelectProgramatically();
        panel.setOpaque(true);

        JFrame frame = new JFrame("JTable Column Selection");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setContentPane(panel);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JTableColumnSelectProgramatically.showFrame();
            }
        });
    }

    public class MyTableModel extends AbstractTableModel {
        private String[] columns = {"ID", "NAME", "AGE", "A STUDENT?"};
        private Object[][] data = {
                {1, "Alice", 20, Boolean.FALSE},
                {2, "Bob", 10, Boolean.TRUE},
                {3, "Carol", 15, Boolean.TRUE},
                {4, "Mallory", 25, Boolean.FALSE}
        };

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

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

        public Object getValueAt(int rowIndex, int columnIndex) {
            return data[rowIndex][columnIndex];
        }

        @Override
        public String getColumnName(int column) {
            return columns[column];
        }

        //
        // This method is used by the JTable to define the default
        // renderer or editor for each cell. For example if you have
        // a boolean data it will be rendered as a check box. A
        // number value is right aligned.
        //
        @Override
        public Class<?> getColumnClass(int columnIndex) {
            return data[0][columnIndex].getClass();
        }
    }

}

Below is the screen capture of the program.

JTable Column Selection Demo