Login.java

package gui;

import java.awt.Container;
import java.awt.GridLayout;
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.JPasswordField;
import javax.swing.JTextField;

public class Sistema extends JFrame {

    private static final long serialVersionUID = -4673040337179571462L;

    JButton logar = new JButton("Logar");
    JButton cancelar = new JButton("Cancelar");

    JTextField nome = new JTextField();
    JPasswordField senha = new JPasswordField();

    private class ListenEvent implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent e) {
            if (e.getSource() == logar) {
                JOptionPane.showMessageDialog(null, "Nome: " + nome.getText().toString() + "\n" + "Senha: " + senha.getPassword().toString());
            } else if(e.getSource() == cancelar){
                nome.setText("");
                senha.setText("");
            }
        }

    }

    public Sistema() {
        super("Sistema de Login");

        Container panContainer = getContentPane();
        panContainer.setLayout(new GridLayout(3, 2));

        panContainer.add(new JLabel("Login: "));
        panContainer.add(nome);
        panContainer.add(new JLabel("Senha: "));
        panContainer.add(senha);
        panContainer.add(logar);
        panContainer.add(cancelar);

        logar.addActionListener(new ListenEvent());
        cancelar.addActionListener(new ListenEvent());

        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setSize(300, 300);
        setVisible(true);
    }

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

}