Introducing JButton Class of Swing in Java

Introduction

 

In this article we discuss the JButton class of Swing in Java.

 

What JButton class is?

 

This class creates a button that has a platform-independent implementation. The JButton class always extends the AbstractButton class.

 

Commonly used Constructors

• JButton()

          Generates a button with no text or icon.

• JButton(String str)

          Generates a specified text button.

• JButton (Icon icn)

          Generates a specified icon object on a button.

 

Commonly used public methods

 

Some commonly used public methods of the Button class are:

• void setText(String str)

          It sets a specified pattern or text on an image.

• String getText()

          It returns the text of the button.

• void setEnabled(boolean bln)

          It enables or disables the button.

• void setIcon(Icon icn)

          It sets the specified icon on the button.

• Icon getIcon()

          Gets the icon of the button.

• void setMnemonic(int a)

          Sets the mnemonic on the button.

• void addActionListener(ActionListener al)

          Adds the action listener to this object.

 

Example

 

In this example; we create a button of an image type. We have used the following image to be displayed on the button.

 

JButtonOfImageEx.java

import javax.swing.*;
import java.awt.event.*;
Public Class JButtonOfImageEx
{
 JButtonOfImageEx()
 {
  JFrame frm = new JFrame();
  JButton btn = new JButton(new ImageIcon("btnimg.jpg"));
  btn.setBounds(145, 105, 105, 45);
  frm.add(btn);
  frm.setSize(630, 410);
  frm.setLayout(null);
  frm.setVisible(true);
  frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 }
 public static void main(String[] args)
 {
  new JButtonOfImageEx();
 }
}

Output

 

 

After pressing Enter in the command prompt we get the following (generates a new window that contains a button of image type).