Add JCheckBox Inside JTable Cell in Java

In this article, we will learn to add/insert a JCheckBox inside a JTable cell in Java. JTable is a powerful component for displaying and editing data in tables. A frequent requirement is to add checkboxes to table cells for boolean data or selection.

JTable

A JTable is a subclass of the JComponent class, and it can be used to create a table with information displayed in multiple rows and columns.

Syntax

The following is the syntax for JTable initialization:

JTable table = new JTable();

When a value is selected from a JTable, a TableModelEvent is generated, which is handled by implementing a TableModelListener interface.

Adding a JCheckBox in a JTable Cell

We can add or insert a checkbox inside a JTable cell by implementing the getColumnClass() method of a Class type.

Step-by-step process for adding/inserting a JCheckBox inside a JTable cell in Java:

Class Definition & Import

The javax.swing.* provides Swing components (JTable, JScrollPane, etc.) while the java.awt.* provides AWT classes (Color, layout managers), and the class extends JFrame to create a window.

import java.awt.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
public class JCheckBoxJTableTest extends JFrame {
        }

Instance Variables

It declares two instance variables: the table variable for the JTable component that will display the data, and the model variable for the DefaultTableModel, which will hold the table's data.

private JTable table;
private DefaultTableModel model;

Constructor Setup

This is where all the initializations occur when an instance of the class is being created. Initializes a Random object used to generate random Boolean values for checkboxes.

public JCheckBoxJTableTest() {
      Random rnd = new Random();

Table Model Setup

Creates a DefaultTableModel with column names: "Check Box1", "Check Box2", and "Check Box3". Overrides getColumnClass() to return Boolean.class for all columns.

model = new DefaultTableModel(new Object[]{"Check Box1","Check Box2", "Check Box3"}, 0) {
   @Override
   public Class getColumnClass(int columnIndex) {
      return Boolean.class;
   }
};

Adding Data to the Model

Adds 10 rows to the model, each row contains a single random boolean value using the rnd.nextBoolean() method. Creates a JTable using the model we configured.

for (int index = 0; index < 10; index++) {
            model.addRow(new Object[]{rnd.nextBoolean(), rnd.nextBoolean(), rnd.nextBoolean()});
}
table = new JTable(model);

Main Method

The main method launches the application by creating an object of JCheckBoxJTableTest.

public static void main(String[] args) {
   new JCheckBoxJTableTest();
}

Example

Below is an example of adding/inserting a JCheckBox inside a JTable cell in Java:

import java.awt.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
public class JCheckBoxJTableTest extends JFrame {
   private JTable table;
   private DefaultTableModel model;
   public JCheckBoxJTableTest() {
      Random rnd = new Random();
      model = new DefaultTableModel(new Object[]{"Check Box1","Check Box2", "Check Box3"}, 0) {
         @Override
         public Class getColumnClass(int columnIndex) {
            return Boolean.class;
         }
      };
      for (int index = 0; index < 10; index++) {
            model.addRow(new Object[]{
                rnd.nextBoolean(),
                rnd.nextBoolean(),
                rnd.nextBoolean()
            });
      }
      table = new JTable(model);
      add(new JScrollPane(table));
      setTitle("JCheckBoxJTable Test");
      setSize(375, 250);
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      setLocationRelativeTo(null);
      setVisible(true);
   }
   public static void main(String[] args) {
      new JCheckBoxJTableTest();
   }
}

Output