How to set JButton to receive focus when JFrame window loads using requestFocusInWindow method

How to set JButton to receive focus when JFrame window loads using requestFocusInWindow method

Below codes makes JButton in a frame window to receive focus.

import javax.swing.JFrame;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JTextField;

public class JButtonGetFocus extends JFrame {
    JButtonGetFocus()
    {
    super("JButton get Focus");
    
    
    JButton button=new JButton("Login");
     button.setBounds(10,40,200,30);
   
     add(button);
     JTextField field=new JTextField();
    field.setBounds(10, 10, 300, 20);
    add(field);
    
     button.addActionListener(new ActionListener(){  
    public void actionPerformed(ActionEvent e){  
            field.setText("Welcome to Download.net.");  
    }  
    }); 
     pack(); 
     button.requestFocusInWindow();
       
    setLayout(null);
    setSize(300,200);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true);
    }
   public static void main(String args[])
   {
   new JButtonGetFocus();
   }
}