Projeto poupanca

import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DecimalFormat;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

/**
 *
 * @author Professor
 */
public class Poupanca {

    static void janelaValores() {
        JFrame j = new JFrame("POUPANÇA");
        j.setSize(400, 400);
        j.setLocationRelativeTo(j);
        j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        j.setResizable(false);
        JPanel p = new JPanel();

        GridLayout layout = new GridLayout(0, 2, 30, 30);
        p.setLayout(layout);

        JLabel jlbAnos = new JLabel("Anos da aplicação:");
        jlbAnos.setHorizontalAlignment(JLabel.RIGHT);
        jlbAnos.setHorizontalTextPosition(JLabel.RIGHT);

        JTextField jtxAnos = new JTextField();
        jtxAnos.setPreferredSize(new Dimension(50, 24));

        JLabel jlbJuros = new JLabel("Juros Mensais:");
        jlbJuros.setHorizontalAlignment(JLabel.CENTER);
        jlbJuros.setHorizontalTextPosition(JLabel.CENTER);
        JTextField jtxJuros = new JTextField();
        jtxJuros.setPreferredSize(new Dimension(50, 24));

        JLabel jlbValor = new JLabel("Valor Mensal:");
        jlbValor.setHorizontalAlignment(JLabel.CENTER);
        jlbValor.setHorizontalTextPosition(JLabel.CENTER);
        JTextField jtxValor = new JTextField();
        jtxValor.setPreferredSize(new Dimension(50, 24));

        JLabel jlbValorP = new JLabel("Valor Previsto:");
        jlbValorP.setHorizontalAlignment(JLabel.CENTER);
        jlbValorP.setHorizontalTextPosition(JLabel.CENTER);
        JLabel jlbValorP2 = new JLabel("R$ ");
        jlbValorP2.setHorizontalAlignment(JLabel.CENTER);
        jlbValorP2.setHorizontalTextPosition(JLabel.CENTER);

        JButton jbtCalcular = new JButton("Calcular");
        JButton jBtLimpar = new JButton("Limpar");
        jBtLimpar.setBounds(50, 100, 95, 30);
        jbtCalcular.setBounds(50, 100, 95, 30);

        jbtCalcular.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent ae) {
                Valores v = new Valores();
                v.setAnos(Integer.parseInt(jtxAnos.getText()));
                v.setJuros(Double.parseDouble(jtxJuros.getText()));
                v.setValor(Double.parseDouble(jtxValor.getText()));
                Double valorPrevisto = v.calcularGanhosPoupanca();
                DecimalFormat formatter = new DecimalFormat("#0.00");

                jlbValorP2.setText(formatter.format(valorPrevisto));

            }
        });

        jBtLimpar.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent ae) {
                jtxJuros.setText("");
                jtxAnos.setText("");
                jtxValor.setText("");
                jlbValorP2.setText("");

            }
        });

        p.add(jlbAnos);
        p.add(jtxAnos);
        p.add(jlbJuros);
        p.add(jtxJuros);
        p.add(jlbValor);
        p.add(jtxValor);
        p.add(jlbValorP);
        p.add(jlbValorP2);

        p.add(jbtCalcular);
        p.add(jBtLimpar);

        j.add(p);
        j.pack();
        j.setVisible(true);
    }

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