How to create the basic Java UI with Swing

MyFrame.java

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.BorderLayout;
import java.awt.Dimension;
 
public class MyFrame extends JFrame {
 
    private JLabel label;
    private JButton button;
 
    public MyFrame() {
        super("MyFrameTitle"); //Superclass constructor
        setDefaultCloseOperation(EXIT_ON_CLOSE);    //when close button pressed, program ends.
        setBounds(500, 200, 300, 300);    //x_pos=500px, y_pos=500px, width=300px, height=300px
        setLayout(new BorderLayout());
        initComponents();
        addComponents();
        setVisible(true);    //make the frame visible
    }
    
    private void initComponents() {
        label = new JLabel("Hello");   //Initialize label
        button = new JButton("Click Me");
        button.addActionListener(new ActionListener() {
            
            public void actionPerformed(ActionEvent ae) {
                Object source = ae.getSource();
                if (source == button) {
                    if (label.getText().equals("Hello"))
                        label.setText("World!");
                    else label.setText("Hello");
                }
                
            }    
        });
    }
    
    private void addComponents() {
        add(label); //add label to MyFrame
        add(button, BorderLayout.SOUTH);
        
    }
    
    public void simulateLabelAdjustment() {
        for (double val = 0.0; val < 100; val += 0.001) {
            label.setText(val + "");
            revalidate();
        }
        
    }
    
    public static void main(String[] args) {
        MyFrame frame = new MyFrame();
        //frame.simulateLabelAdjustment();
    }
}