[본삭금] 자바 텍스트필드 비게하는법 좀 도와주세요 ㅜㅜ

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

public class addTwoNumber extends JFrame implements ActionListener {

JButton addButton = new JButton("add");

JButton exitButton = new JButton("exit");

JButton resetButton = new JButton("reset");

JTextField num1 = new JTextField(5);

JTextField num2 = new JTextField(5);

JTextField output = new JTextField(8);

int nm1,nm2, out =0 ;

String n1, n2;

public addTwoNumber()

{

super("add two numbers");

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JPanel myPanel = new JPanel();

myPanel.add(num1);

myPanel.add(num2);

myPanel.add(output);

myPanel.add(addButton);

myPanel.add(exitButton);

myPanel.add(resetButton);

setContentPane(myPanel);

exitButton.addActionListener(this);

addButton.addActionListener(this);

}

public static void main(String[] args)

{

addTwoNumber frame = new addTwoNumber();

frame.setSize(600,100);

frame.setVisible(true);

}

public void actionPerformed(ActionEvent e)

{

Object source = e.getSource();

if(source == exitButton)

{

System.exit(0);

}

else if(source == addButton)

{

n1 = num1.getText();

nm1 = Integer.parseInt(n1);

n2 = num2.getText();

nm2 = Integer.parseInt(n2);

out = nm1+nm2;

String nu = (""+out);

output.setText(nu);

}

else if(source == resetButton)

{

String empty = ("");

num1.setText(empty);

num2.setText(empty);

output.setText(empty);

}

볼드한부분이 작동을하지않습니다 1 + 1 = 2 가나온이후 리셋버튼을누르면 세 필드가 전부 비게하고싶은데.. 아무변화가없네요 조언좀 부탁드립니다