Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.awt.Component;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;

import javax.swing.JButton;
import javax.swing.JFrame;

public class Main {
    public static void main(String[] argv) throws Exception {
        JButton component = new JButton("a");
        component.addFocusListener(new MyFocusListener());

        JFrame f = new JFrame();
        f.add(component);
        f.pack();
        f.setVisible(true);

    }
}

class MyFocusListener extends FocusAdapter {
    public void focusGained(FocusEvent evt) {

        Component c = evt.getOppositeComponent();
        System.out.println(c.getName());
    }

    public void focusLost(FocusEvent evt) {

        Component c = evt.getOppositeComponent();
        System.out.println(c.getName() + "Opposite Component");
    }
}