In this tutorial, you will learn how to use JCheckBox class to create checkboxes.
To create checkboxes, you use the JCheckBox class. The JCheckBox class inherits all functionality of JToogleButton class. A checkbox allows the user to turn something on and off. You can create a checkbox with text, icon or both. Here are the most typical constructors of JCheckBox class:
| JCheckBox Constructors | Meanings |
|---|---|
| public JCheckBox( ) | Creates a checkbox without text and icon. The state of the checkbox is not selected. |
| public JCheckBox(Icon icon) | Creates a checkbox with icon |
| public JCheckBox(Icon icon, boolean selected) | Creates a checkbox with icon and initialize the state of checkbox by the boolean parameter selected |
| public JCheckBox(String text) | Creates a checkbox with text |
| public JCheckBox(String text, boolean selected) | Creates a checkbox with text and initialize the state of the checkbox |
| public JCheckBox(String text, Icon icon) | Creates a checkbox which displays both text and icon. |
| public JCheckBox(String text, Icon icon, boolean selected) | Creates a checkbox which displays both text and icon. The state of the checkbox can be initialized. |
There are two ways to work with checkbox’s state:
- You use addActionListener() or AddItemListener() method so that whenever the state of checkbox change you can have corresponding logic to handle this.
- Use isSelected() to check whether the checkbox is selected.
JCheckbox Demo Application
In this example, we create a checkbox. When the user clicks on it, a message will display to notify the checkbox’s state. Here is the output of the demo application:
When user checks the checkbox, a message popup will display like the following screenshot:
Here is the code sample of JCheckBox demo:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 | package jcheckboxdemo; import java.awt.BorderLayout; import java.awt.event.ItemEvent; import java.awt.event.ItemListener; import javax.swing.JCheckBox; import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.JPanel; public class Main { public static void main(String[] args) { final JFrame frame = new JFrame("JCheckBox Demo"); JCheckBox chkSwing = new JCheckBox("Java Swing"); chkSwing.addItemListener( new ItemListener() { public void itemStateChanged(ItemEvent e) { if (e.getStateChange() == ItemEvent.SELECTED) { JOptionPane.showMessageDialog(frame, "CheckBox is selected"); } else { JOptionPane.showMessageDialog(frame, "CheckBox is unselected"); } } }); // Add checkbox to a panel JPanel buttonPanel = new JPanel(); buttonPanel.add(chkSwing); // Frame setting frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(300, 100); frame.getContentPane().add(buttonPanel, BorderLayout.SOUTH); frame.setVisible(true); } } |