Projeto calculadora

/** Colar após o packpage, nome do projeto: calculadora
 *
 * @author Professor Hercio Neto
 */

import java.awt.Dimension;
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.JPanel;
import javax.swing.JTextField;

public class Calculadora {

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

        GridLayout layout = new GridLayout(0,2,20,20);
        p.setLayout(layout);


        JLabel jLbnum1 = new JLabel("Número 1:");
        jLbnum1.setHorizontalAlignment(JLabel.CENTER);
        jLbnum1.setHorizontalTextPosition(JLabel.CENTER);
        JTextField jTxnum1 = new JTextField();
        jTxnum1.setPreferredSize(new Dimension( 50, 24 ));

        JLabel jLbnum2 = new JLabel("Número 2:");
        jLbnum2.setHorizontalAlignment(JLabel.CENTER);
        jLbnum2.setHorizontalTextPosition(JLabel.CENTER);
        JTextField jTxnum2 = new JTextField();

        jTxnum2.setPreferredSize(new Dimension( 50, 24 ));


        JLabel jLbresultado = new JLabel("RESULTADO");
        jLbresultado.setHorizontalAlignment(JLabel.CENTER);
        jLbresultado.setHorizontalTextPosition(JLabel.CENTER);
        JLabel jLbVazio = new JLabel("");


        jLbresultado.setBounds(50,100,95,30);

        JButton jBtSoma=new JButton("Somar");
        JButton jBtSubtrair=new JButton("Subtrair");
        JButton jBtMultiplicar=new JButton("Multiplicar");
        JButton jBtDividir=new JButton("Dividir");

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

        jBtSoma.setBounds(50,100,95,30);

        jBtSoma.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent ae)
              {
               Calculos c = new Calculos();
               c.setNumero1(Double.parseDouble(jTxnum1.getText()));
               c.setNumero2(Double.parseDouble(jTxnum2.getText()));
               c.soma();
               jLbresultado.setText(c.getCalculo().toString());

            }
        });


        jBtSubtrair.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent ae)
              {
               Calculos c = new Calculos();
               c.setNumero1(Double.parseDouble(jTxnum1.getText()));
               c.setNumero2(Double.parseDouble(jTxnum2.getText()));
               c.subtracao();
               jLbresultado.setText(c.getCalculo().toString());

            }
        });

        jBtMultiplicar.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent ae)
              {
               Calculos c = new Calculos();
               c.setNumero1(Double.parseDouble(jTxnum1.getText()));
               c.setNumero2(Double.parseDouble(jTxnum2.getText()));
               c.multiplicacao();
               jLbresultado.setText(c.getCalculo().toString());

            }
        });

        jBtDividir.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent ae)
              {
               Calculos c = new Calculos();
               c.setNumero1(Double.parseDouble(jTxnum1.getText()));
               c.setNumero2(Double.parseDouble(jTxnum2.getText()));
               c.divisao();
               jLbresultado.setText(c.getCalculo().toString());

            }
        });


        jBtLimpar.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent ae)
              {

               jTxnum1.setText("");
              jTxnum2.setText("");

               jLbresultado.setText("");

            }
        });

        p.add(jLbnum1);
        p.add(jTxnum1);
        p.add(jLbnum2);
        p.add(jTxnum2);
        p.add(jLbVazio);

        p.add(jLbresultado);
        p.add(jBtSoma);
        p.add(jBtSubtrair);
        p.add(jBtMultiplicar);
        p.add(jBtDividir);
        p.add(jBtLimpar);
        j.add(p);
        j.pack();
        j.setVisible(true);
    }

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

    }
}