(Java代码)编写具有图形用户界面（GUI)的日历组件显示日期和时间。 ·主要功能： 1、显示当月日历，当前日期、当前时间; 2、可查询任意月以及任意年的日历： 3、正常运行和退出程序。

以下是一个简单的Java Swing程序，可以实现一个具有图形用户界面的日历组件，能够显示当前日期和时间，并可查询任意月份和年份的日历。

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

public class CalendarGUI extends JFrame implements ActionListener {

    private JLabel titleLabel, dateLabel, timeLabel;
    private JButton prevMonthButton, nextMonthButton, prevYearButton, nextYearButton, goButton;
    private JTextField monthField, yearField;
    private JPanel calendarPanel;

    private Calendar cal;

    public CalendarGUI() {
        super("Calendar");

        // 设置窗口大小和位置
        setSize(500, 400);
        setLocationRelativeTo(null);

        // 创建标题标签
        titleLabel = new JLabel("Calendar");
        titleLabel.setFont(new Font("Arial", Font.BOLD, 24));
        titleLabel.setHorizontalAlignment(SwingConstants.CENTER);

        // 创建日期和时间标签
        dateLabel = new JLabel();
        timeLabel = new JLabel();
        updateTime();

        // 创建查询按钮和文本框
        prevMonthButton = new JButton("<");
        nextMonthButton = new JButton(">");
        prevYearButton = new JButton("<<");
        nextYearButton = new JButton(">>");
        goButton = new JButton("Go");
        monthField = new JTextField(2);
        yearField = new JTextField(4);

        // 设置按钮和文本框的事件监听器
        prevMonthButton.addActionListener(this);
        nextMonthButton.addActionListener(this);
        prevYearButton.addActionListener(this);
        nextYearButton.addActionListener(this);
        goButton.addActionListener(this);
        monthField.addActionListener(this);
        yearField.addActionListener(this);

        // 创建日历面板
        calendarPanel = new JPanel(new GridLayout(0, 7));
        calendarPanel.setBorder(BorderFactory.createEtchedBorder());

        // 添加组件到窗口中
        Container contentPane = getContentPane();
        contentPane.setLayout(new BorderLayout());
        contentPane.add(titleLabel, BorderLayout.NORTH);
        contentPane.add(dateLabel, BorderLayout.CENTER);
        contentPane.add(timeLabel, BorderLayout.SOUTH);
        contentPane.add(prevMonthButton, BorderLayout.WEST);
        contentPane.add(nextMonthButton, BorderLayout.EAST);
        contentPane.add(prevYearButton, BorderLayout.WEST);
        contentPane.add(nextYearButton, BorderLayout.EAST);
        contentPane.add(monthField, BorderLayout.WEST);
        contentPane.add(yearField, BorderLayout.EAST);
        contentPane.add(goButton, BorderLayout.CENTER);
        contentPane.add(calendarPanel, BorderLayout.SOUTH);

        // 初始化日历
        cal = Calendar.getInstance();
        updateCalendar(cal);
    }

    public void actionPerformed(ActionEvent e) {
        Object source = e.getSource();
        int month = cal.get(Calendar.MONTH);
        int year = cal.get(Calendar.YEAR);

        // 处理按钮事件
        if (source == prevMonthButton) {
            if (month == Calendar.JANUARY) {
                cal.set(Calendar.MONTH, Calendar.DECEMBER);
                cal.set(Calendar.YEAR, year - 1);
            } else {
                cal.set(Calendar.MONTH, month - 1);
            }
            updateCalendar(cal);
        } else if (source == nextMonthButton) {
            if (month == Calendar.DECEMBER) {
                cal.set(Calendar.MONTH, Calendar.JANUARY);
                cal.set(Calendar.YEAR, year + 1);
            } else {
                cal.set(Calendar.MONTH, month + 1);
            }
            updateCalendar(cal);
        } else if (source == prevYearButton) {
            cal.set(Calendar.YEAR, year - 1);
            updateCalendar(cal);
        } else if (source == nextYearButton) {
            cal.set(Calendar.YEAR, year + 1);
            updateCalendar(cal);
        } else if (source == goButton || source == monthField || source == yearField) {
            try {
                int newMonth = Integer.parseInt(monthField.getText()) - 1;
                int newYear = Integer.parseInt(yearField.getText());
                if (newMonth < Calendar.JANUARY || newMonth > Calendar.DECEMBER || newYear < 0) {
                    throw new IllegalArgumentException();
                }
                cal.set(Calendar.MONTH, newMonth);
                cal.set(Calendar.YEAR, newYear);
                updateCalendar(cal);
            } catch (NumberFormatException ex) {
                JOptionPane.showMessageDialog(this, "Invalid input");
            } catch (IllegalArgumentException ex) {
                JOptionPane.showMessageDialog(this, "Invalid month or year");
            }
        }
    }

    private void updateCalendar(Calendar cal) {
        // 清空日历面板
        calendarPanel.removeAll();

        // 创建日历标题
        String[] daysOfWeek = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
        for (String day : daysOfWeek) {
            JLabel label = new JLabel(day, JLabel.CENTER);
            label.setBorder(BorderFactory.createEtchedBorder());
            calendarPanel.add(label);
        }

        // 获取当前月份的第一天
        Calendar tempCal = (Calendar) cal.clone();
        tempCal.set(Calendar.DAY_OF_MONTH, 1);

        // 计算当前月份的总天数
        int numDays = tempCal.getActualMaximum(Calendar.DAY_OF_MONTH);

        // 计算当前月份的第一天是星期几
        int firstDayOfWeek = tempCal.get(Calendar.DAY_OF_WEEK) - 1;

        // 添加当前月份的日期到日历面板中
        for (int i = 0; i < firstDayOfWeek; i++) {
            calendarPanel.add(new JLabel(""));
        }
        for (int i = 1; i <= numDays; i++) {
            JLabel label = new JLabel(Integer.toString(i), JLabel.CENTER);
            label.setBorder(BorderFactory.createEtchedBorder());
            calendarPanel.add(label);
        }

        // 更新窗口标题和日期标签
        titleLabel.setText(cal.getDisplayName(Calendar.MONTH, Calendar.LONG, Locale.getDefault()) + " " + cal.get(Calendar.YEAR));
        dateLabel.setText(cal.getDisplayName(Calendar.DAY_OF_WEEK, Calendar.LONG, Locale.getDefault()) + ", " + cal.get(Calendar.DAY_OF_MONTH));

        // 重新绘制窗口
        revalidate();
        repaint();
    }

    private void updateTime() {
        // 更新时间标签
        Date now = new Date();
        timeLabel.setText(now.toString());

        // 每秒钟更新一次时间
        Timer timer = new Timer(1000, new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                Date now = new Date();
                timeLabel.setText(now.toString());
            }
        });
        timer.start();
    }

    public static void main(String[] args) {
        CalendarGUI app = new CalendarGUI();
        app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        app.setVisible(true);
    }

}