Java JButton class example

JButton

Java Swing Tutorial Explaining the JButton Component. The abstract class AbstractButton extends class JComponent and provides a foundation for a family of button classes, including JButton. A button is a component the user clicks to trigger a specific action.

There are several types of buttons in Java, all are subclasses of AbstractButton.

• command buttons: is created with class JButton. It generates ActionEvent.
• toggle buttons: have on/off or true/false values.
• check boxes: a group of buttons. It generates ItemEvent.
• radio buttons: a group of buttons in which only one can be selected. It generates ItemEvent.

JButton Source Code

import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import java.net.URL; import javax.swing.AbstractButton; import javax.swing.ImageIcon; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; public class JButtonDemo extends JPanel implements ActionListener { protected static JButton jbnLeft, jbnMiddle, jbnRight; public JButtonDemo() { // Create Icons that can be used with the jButtons ImageIcon leftButtonIcon = createImageIcon("rightarrow.JPG"); ImageIcon middleButtonIcon = createImageIcon("java-swing-tutorial.JPG"); ImageIcon rightButtonIcon = createImageIcon("leftarrow.JPG"); jbnLeft = new JButton("Disable centre button", leftButtonIcon); jbnLeft.setVerticalTextPosition(AbstractButton.CENTER); jbnLeft.setHorizontalTextPosition(AbstractButton.LEADING); jbnLeft.setMnemonic(KeyEvent.VK_D); // Alt-D clicks the button jbnLeft.setActionCommand("disable"); jbnLeft.setToolTipText("disable the Centre button."); // Adding Tool // tips jbnMiddle = new JButton("Centre button", middleButtonIcon); jbnMiddle.setVerticalTextPosition(AbstractButton.BOTTOM); jbnMiddle.setHorizontalTextPosition(AbstractButton.CENTER); jbnMiddle.setMnemonic(KeyEvent.VK_M); // Alt-M clicks the button jbnMiddle.setToolTipText("Centre button"); jbnRight = new JButton("Enable centre button", rightButtonIcon); // Use the default text position of CENTER, TRAILING (RIGHT). jbnRight.setMnemonic(KeyEvent.VK_E); // Alt-E clicks the button jbnRight.setActionCommand("enable"); jbnRight.setEnabled(false); // Disable the Button at creation time // Listen for actions on Left and Roght Buttons jbnLeft.addActionListener(this); jbnRight.addActionListener(this); jbnRight.setToolTipText("Enable the Centre button."); // Add Components to the frame, using the default FlowLayout. add(jbnLeft); add(jbnMiddle); add(jbnRight); } public void actionPerformed(ActionEvent e) { if ("disable".equals(e.getActionCommand())) { jbnMiddle.setEnabled(false); jbnLeft.setEnabled(false); jbnRight.setEnabled(true); } else { jbnMiddle.setEnabled(true); jbnLeft.setEnabled(true); jbnRight.setEnabled(false); } } // Returns an ImageIcon, or null if the path was invalid. protected static ImageIcon createImageIcon(String path) { URL imgURL = JButtonDemo.class.getResource(path); if (imgURL != null) { return new ImageIcon(imgURL); } else { System.err.println("Couldn't find image in system: " + path); return null; } } // Create the GUI and show it. private static void createGUI() { JFrame.setDefaultLookAndFeelDecorated(true); // Create and set up the frame. JFrame frame = new JFrame("jButton usage demo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // Create and set up the content pane. JButtonDemo buttonContentPane = new JButtonDemo(); buttonContentPane.setOpaque(true); // content panes must be opaque frame.getRootPane().setDefaultButton(jbnLeft); frame.setContentPane(buttonContentPane); // Display the window. frame.pack(); frame.setVisible(true); } public static void main(String[] args) { javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createGUI(); } }); } }

Output

Download jButton Source Code

Another Example: JButton Source Code

import java.awt.*; import java.awt.event.*; import javax.swing.*; public class JButtonDemo2 { JFrame jtfMainFrame; JButton jbnButton1, jbnButton2; JTextField jtfInput; JPanel jplPanel; public JButtonDemo2() { jtfMainFrame = new JFrame("Which Button Demo"); jtfMainFrame.setSize(50, 50); jbnButton1 = new JButton("Button 1"); jbnButton2 = new JButton("Button 2"); jtfInput = new JTextField(20); jplPanel = new JPanel(); jbnButton1.setMnemonic(KeyEvent.VK_I); //Set ShortCut Keys jbnButton1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { jtfInput.setText("Button 1!"); } }); jbnButton2.setMnemonic(KeyEvent.VK_I); jbnButton2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { jtfInput.setText("Button 2!"); } }); jplPanel.setLayout(new FlowLayout()); jplPanel.add(jtfInput); jplPanel.add(jbnButton1); jplPanel.add(jbnButton2); jtfMainFrame.getContentPane().add(jplPanel, BorderLayout.CENTER); jtfMainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); jtfMainFrame.pack(); jtfMainFrame.setVisible(true); } public static void main(String[] args) { // Set the look and feel to Java Swing Look try { UIManager.setLookAndFeel(UIManager .getCrossPlatformLookAndFeelClassName()); } catch (Exception e) { } JButtonDemo2 application = new JButtonDemo2(); } }

Output

Download jButton Source Code

Java JButton Hierarchy

javax.swing
Class JButton 
java.lang.Object
java.awt.Component
java.awt.Container
javax.swing.JComponent
javax.swing.AbstractButton
javax.swing.JButton
All Implemented Interfaces: 
Accessible, ImageObserver, ItemSelectable, MenuContainer, Serializable, SwingConstants
Direct Known Subclasses:
BasicArrowButton, MetalComboBoxButton

JButton Constructor

JButton()
Creates a button with no set text or icon.

JButton(Action a)
Creates a button where properties are taken from the Action supplied.

JButton(Icon icon)
Creates a button with an icon.

JButton(String text)
Creates a button with text.

JButton(String text, Icon icon)
Creates a button with initial text and an icon.