Creating JTextFields and JPasswordField in Java Swings

package jtextfields;

import javax.swing.*;
import javax.swing.text.Document;
import javax.swing.text.PlainDocument;
import java.awt.*;

public class JTextFieldExample extends JFrame {
	JTextField textField1,textField2,textField3,textField4;
	
	public JTextFieldExample() {
		 // Create a JFrame to hold everything
        setTitle("JTextField Example");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(400, 300);
        setLayout(null);

        // Create JTextField using default constructor
        textField1 = new JTextField();
        textField1.setText("Default Constructor");
        textField1.setBounds(50, 20, 120, 30);
        add(textField1);

        // Create JTextField with specified columns
        textField2 = new JTextField(10);
        textField2.setText("10 Columns");
        textField2.setBounds(50, 60, 120, 30);
        add(textField2);

        // Create JTextField with specified text
        textField3 = new JTextField("Specified Text");
        textField3.setBounds(50, 100, 120, 30);
        add(textField3);

        // Create JTextField with specified text and columns
        textField4 = new JTextField("Text and Columns", 15);
        textField4.setBounds(50, 140, 120, 30);
        add(textField4);

        // Manipulate JTextField methods
        textField1.setColumns(20);
        textField2.setHorizontalAlignment(JTextField.CENTER);
        textField3.setEditable(false);
        textField4.setMargin(new Insets(5, 5, 5, 5));

        // Display the frame
        setVisible(true);
	}

    public static void main(String[] args) {
       new JTextFieldExample();
    }
}