能否帮写一个带界面的“两个数交换”程序,该如何处理

import java.awt.EventQueue;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.JOptionPane;import javax.swing.JPanel;import javax.swing.JTextField;import javax.swing.border.EmptyBorder;public class Test extends JFrame {    private JPanel contentPane;    private JTextField n1;    private JTextField n2;    /**     * Launch the application.     */    public static void main(String[] args) {        EventQueue.invokeLater(new Runnable() {            public void run() {                try {                    Test frame = new Test();                    frame.setVisible(true);                } catch (Exception e) {                    e.printStackTrace();                }            }        });    }    /**     * Create the frame.     */    public Test() {        setTitle("test");        setResizable(false);        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        setBounds(100, 100, 280, 99);        contentPane = new JPanel();        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));        setContentPane(contentPane);        contentPane.setLayout(null);                n1 = new JTextField();        n1.setBounds(47, 10, 66, 21);        contentPane.add(n1);        n1.setColumns(10);                n2 = new JTextField();        n2.setBounds(180, 10, 66, 21);        contentPane.add(n2);        n2.setColumns(10);                JButton button = new JButton("\u4EA4\u6362");        button.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent arg0) {                exchange();            }        });        button.setBounds(57, 41, 74, 23);        contentPane.add(button);                JLabel label = new JLabel("\u6570\u5B571\uFF1A");        label.setBounds(0, 10, 47, 21);        contentPane.add(label);                JLabel label_1 = new JLabel("\u6570\u5B572\uFF1A");        label_1.setBounds(127, 10, 47, 21);        contentPane.add(label_1);                JButton button_1 = new JButton("\u6E05\u7A7A");        button_1.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent arg0) {                n1.setText("");                n2.setText("");            }        });        button_1.setBounds(147, 41, 74, 23);        contentPane.add(button_1);    }        private void exchange(){        try {            int numberInt_1=Integer.parseInt(n1.getText());            int numberInt_2=Integer.parseInt(n2.getText());            System.out.println("交换前：\n\t数字一："+numberInt_1+"\n\t数字二："+numberInt_2);            int temp;            /*             * 先交换值，再显示在文本框中。             * 当然也可以直接显示，不用在顶定义个变量。这样只需             * n1.setText(""+numberInt_2);             * n2.setText(""+numberInt_1);             */            temp=numberInt_1;            numberInt_1=numberInt_2;            numberInt_2=temp;            System.out.println("交换后：\n\t数字一："+numberInt_1+"\n\t数字二："+numberInt_2);            n1.setText(""+numberInt_1);            n2.setText(""+numberInt_2);        } catch (Exception e) {            JOptionPane.showMessageDialog(n1, "只能输入数字。");        }    }}