GUI华氏温度摄氏温度以及k是温度转换

package com.yd.cn;

import java.awt.Container;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JTextField;

public class Textarea extends JFrame implements ActionListener {

private JButton transformFButton = new JButton("摄氏");
private JButton transformCButton = new JButton("华氏转摄氏");
private JButton transformKButton = new JButton("K氏");
private JTextField fTextField = new JTextField();
private JTextField cTextField = new JTextField();
private JTextField KTextField = new JTextField();
float c, f, k;

public Textarea() {
super("华氏温度摄氏温度转换");
try {
init();
} catch (Exception e) {
e.printStackTrace();
}
}

private void init() {
fTextField.setBounds(10, 30, 100, 25);
cTextField.setBounds(130, 30, 100, 25);
KTextField.setBounds(230, 30, 100, 25);
transformCButton.setBounds(10, 58, 100, 25);
transformFButton.setBounds(130, 58, 100, 25);
transformKButton.setBounds(230, 58, 100, 25);
transformCButton.addActionListener(this);
Container c = getContentPane();
c.add(fTextField);
c.add(cTextField);
c.add(KTextField);

c.add(transformCButton);
c.add(transformFButton);
c.add(transformKButton);
c.setLayout(null);

this.setSize(380, 150);
this.setResizable(false);
this.setLocationRelativeTo(null);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}

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

public void actionPerformed(ActionEvent e) {
// 华氏温度F与摄氏度C
// F= C* 9/5 + 32
// C=(F-32)*5/9
if (e.getSource() == transformCButton) {
try {
f = Float.parseFloat(fTextField.getText());
c = (f - 32) * 5 / 9;
k = c + 273;
cTextField.setText(String.valueOf(c));
KTextField.setText(String.valueOf(k));
} catch (Exception ex) {
ex.printStackTrace();
}
}
}

}