How to set action command to JButton in Java

With set action command, here we are displaying a message in the console on the click of a button.

Set the button first:

JButton btn = new JButton("Demo Button");

Now, set Action Listener to fire when the button is clicked:

ActionListener actionListener = new ActionListener() {
   public void actionPerformed(ActionEvent event) {
      String str = event.getActionCommand();
      System.out.println("Clicked = " + str);
   }
};

The following is an example to set action command to JButton:

Example

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JOptionPane;
public class SwingDemo {
   public static void main(final String args[]) {
      JButton btn = new JButton("Demo Button");
      ActionListener actionListener = new ActionListener() {
         public void actionPerformed(ActionEvent event) {
            String str = event.getActionCommand();
            System.out.println("Clicked = " + str);
         }
      };
      btn.setActionCommand("FirstButton");
      btn.addActionListener(actionListener);
      JOptionPane.showMessageDialog(null, btn);
   }
}

Output

When you will click the “Demo Button” above, the following text would be visible in EclipseIDE output window: