login en jframe java

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;


public class login extends JFrame implements ActionListener{
	
	JFrame frame = new JFrame("login");
	JPanel panel = new JPanel();
	JLabel labelUsername = new JLabel("Username");
	JTextField textFieldUsername = new JTextField(20);
	JLabel labelPassword = new JLabel("Password");
	JPasswordField passwordField = new JPasswordField(20);
	JButton buttonLogin = new JButton("Login");
	JButton buttonCancel = new JButton("cancel");
	
	public login (){
		setSize(350,