Java Gui : Konversi Suhu in Java

/**
 * @(#)KonversiGuiNew.java
 *
 * KonversiGuiNew application
 *
 * @author
 * @version 1.00 2017/10/2
 */

public class KonversiGuiNew {

    public static void main(String[] args) {
        JavaGui obj = new JavaGui();
        obj.setVisible(true);
    }
}


/**
* Class JavaGui
*/

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;


class JavaGui extends JFrame {

    JPanel panel = new JPanel();

    JLabel label1 = new JLabel("Celcius");
    JLabel label2 = new JLabel("Reamur");
    JLabel label3 = new JLabel("Farenheit");
    JLabel label4 = new JLabel("Reamur");

    JTextField celcius = new JTextField();
    JTextField reamur = new JTextField();
    JTextField farenheit = new JTextField();

    //JButton btnConvert = new JButton("Convert");
    JButton btnCelciusToRToF = new JButton("Convert");
    JButton btnReamurToCToF = new JButton("Convert");
    JButton btnFarenheitToCToR = new JButton("Convert");
    JButton btnClear = new JButton("Clear");


    public JavaGui(){
        panel.setLayout(null);
        add(panel);

        label1.setBounds(15, 20, 80, 25);
        label2.setBounds(15, 50, 80, 25);
        label3.setBounds(15, 80, 80, 25);

        celcius.setBounds(120, 20, 100, 25);
        reamur.setBounds(120, 50, 100, 25);
        farenheit.setBounds(120, 80, 100, 25);

        //btnConvert.setBounds(15, 120, 90, 25);
        btnCelciusToRToF.setBounds(250, 20, 90, 25);
        btnReamurToCToF.setBounds(250, 50, 90, 25);
        btnFarenheitToCToR.setBounds(250, 80, 90, 25);
        btnClear.setBounds(100, 120, 90, 25);

        panel.add(label1);
        panel.add(label2);
        panel.add(label3);

        panel.add(celcius);
        panel.add(reamur);
        panel.add(farenheit);

        //panel.add(btnConvert);
        panel.add(btnCelciusToRToF);
        panel.add(btnReamurToCToF);
        panel.add(btnFarenheitToCToR);
        panel.add(btnClear);

        setTitle("Konversi Suhu");
        setBounds(500, 200, 400, 200);
        setDefaultCloseOperation(EXIT_ON_CLOSE);

        /**btnConvert.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
                    int tampung = 0, tampung1 = 1, tampung2 = 2;
                    if(celciusToRToF(tampung) == 0){
                        celciusToRToF(tampung);
                        tampung2 = 3;
                    }
                    if(reamurToCToF(tampung1) == 1){
                        reamurToCToF(tampung1);
                        tampung = 1;
                    }
                    if(farenheitToCToR(tampung2) == 2){
                        farenheitToCToR(tampung2);
                        tampung1 = 2;
                    }
            }
        });**/

        btnCelciusToRToF.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
                celciusToRToF();
            }
        });

        btnReamurToCToF.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
                reamurToCToF();
            }
        });
        btnFarenheitToCToR.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
                farenheitToCToR();
            }
        });

        btnClear.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
                clearData();
            }
        });

    }

    float hasil;
    final float suhuTampung = 4, suhuTampung2 = 9;

    public float celciusToRToF(){
        //Celcius To Reamur
        float celciusIsi = Float.parseFloat(celcius.getText());
        hasil = suhuTampung / 5 * celciusIsi;
        reamur.setText(Float.toString(hasil));
        //Celcius To Farenheit
        hasil = (suhuTampung2 / 5 * celciusIsi) + 32;
        farenheit.setText(Float.toString(hasil));
        return hasil;
    }

    public float reamurToCToF(){
        //Reamur To Celcius
        float reamurIsi = Float.parseFloat(reamur.getText());
        hasil = 5 / suhuTampung * reamurIsi;
        celcius.setText(Float.toString(hasil));
        //Reamur To Farenheit
        hasil = (suhuTampung2 / suhuTampung * reamurIsi) + 32;
        farenheit.setText(Float.toString(hasil));

        return hasil;
    }

    public float farenheitToCToR(){
        //Farenheit To Celcius
        float farenheitIsi = Float.parseFloat(farenheit.getText());
        hasil = 5 / suhuTampung2 * (farenheitIsi - 32);
        celcius.setText(Float.toString(hasil));
        //Farenheit To Reamur
        hasil = suhuTampung / suhuTampung2 * (farenheitIsi - 32);
        reamur.setText(Float.toString(hasil));

        return hasil;
    }

    public void clearData(){
        celcius.setText("");
        reamur.setText("");
        farenheit.setText("");
    }

}