What is the use of action command in event handling ? Explain with example.

Action command is used to handle event caused by the Buttons.

Example

 import javax.swing.*;

import java.awt.*;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

public class ActionDemo extends JFrame implements ActionListener {

JLabel l1, l2, l3;

JTextField t1, t2, t3;

JButton b1, b2;

public ActionDemo() {

super("Handling Action Event");

l1 = new JLabel("Click on button to get result");

t1 = new JTextField(20);

b1 = new JButton("Demo Button");

b1.addActionListener(this);

setLayout(new FlowLayout(FlowLayout.CENTER, 150, 10));

add(l1);

add(t1);

add(b1);

setSize(400, 300);

setVisible(true);

}

public void actionPerformed(ActionEvent actionEvent) {

String str = actionEvent.getActionCommand(); //using action command

t1.setText("You have clicked " + str);

}

public static void main(String[] args) {

new ActionDemo();

}

}

In the above example if clicked on the Demo Button, with the help of the getActionCommand() method we will be able to see the click event done on the output.