帮我用java编写一个图形界面程序，完成简单的火车票购买。假设火车站有：南宁、柳州、玉林、百色、北海。用户指定火车票的乘客名字、起点、终点、日期时间。要求起点、终点用组合框实现，在一个日历窗口上选择日期和时刻。当用户输入完毕，用一个弹出窗口显示完整的输入信息。

好的，我可以帮你完成这个任务。下面是代码实现：

import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JButton;
import com.toedter.calendar.JCalendar;
import java.awt.event.ActionListener;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.awt.event.ActionEvent;

public class TrainTicket extends JFrame {

    private JPanel contentPane;
    private JComboBox<String> startComboBox;
    private JComboBox<String> endComboBox;
    private JCalendar calendar;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    TrainTicket frame = new TrainTicket();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public TrainTicket() {
        setTitle("火车票购买");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        startComboBox = new JComboBox<String>();
        startComboBox.setBounds(10, 50, 100, 21);
        startComboBox.addItem("南宁");
        startComboBox.addItem("柳州");
        startComboBox.addItem("玉林");
        startComboBox.addItem("百色");
        startComboBox.addItem("北海");
        contentPane.add(startComboBox);

        JLabel labelFrom = new JLabel("起点:");
        labelFrom.setBounds(10, 30, 54, 15);
        contentPane.add(labelFrom);

        endComboBox = new JComboBox<String>();
        endComboBox.setBounds(10, 110, 100, 21);
        endComboBox.addItem("南宁");
        endComboBox.addItem("柳州");
        endComboBox.addItem("玉林");
        endComboBox.addItem("百色");
        endComboBox.addItem("北海");
        contentPane.add(endComboBox);

        JLabel labelTo = new JLabel("终点:");
        labelTo.setBounds(10, 90, 54, 15);
        contentPane.add(labelTo);

        calendar = new JCalendar();
        calendar.setBounds(150, 50, 200, 150);
        contentPane.add(calendar);

        JLabel labelTime = new JLabel("日期和时刻:");
        labelTime.setBounds(150, 30, 100, 15);
        contentPane.add(labelTime);

        JButton button = new JButton("购买");
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                Date date = calendar.getDate();
                String