【例1】列印系統當前日曆月份資訊。

import java.text.DateFormatSymbols;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.Locale;

/**
 * 列印當前月份日曆
 * 
 * @date 2017-07-08
 * @author HaleyTiger
 */
public class CalendarTest {

    public static void main(String[] args) {
        // 設定日曆的顯示的地區（根據自己的需要寫）
 

        Locale.setDefault(Locale.ENGLISH);

        // GregorianCalendar是Calendar的子類
        GregorianCalendar gc = new GregorianCalendar();
        int today = gc.get(Calendar.DAY_OF_MONTH);
        int month = gc.get(Calendar.MONTH);

        // 設定月份的起始日期為1
        gc.set(Calendar.DAY_OF_MONTH, 1);

        // 獲取一週中的第幾天
 

        int weekday = gc.get(Calendar.DAY_OF_WEEK);

        // 獲取一週中的第一天
        int firstDayOfWeek = gc.getFirstDayOfWeek();

        // 計算月份第一行的縮排數
        int indent = 0;// 縮排數
        while (weekday != firstDayOfWeek) {
            indent++;
            gc.add(Calendar.DAY_OF_MONTH, -1);// 日期減1
            weekday = gc.get
 
(Calendar.DAY_OF_WEEK);
        }

        // 列印星期名
        String[] weekdayNames = new DateFormatSymbols().getShortWeekdays();
        do {
            System.out.printf("%4s", weekdayNames[weekday]);
            gc.add(Calendar.DAY_OF_MONTH, 1);
            weekday = gc.get(Calendar.DAY_OF_WEEK);
        } while (weekday != firstDayOfWeek);
        System.out.println();

        // 列印日曆第一行的縮排空格
        for (int i = 0; i <= indent; i++) {
            System.out.print("  ");// 兩個空格
        }

        // 設定月份的起始日期為1
        gc.set(Calendar.DAY_OF_MONTH, 1);

        // 列印日期
        do {
            // 列印天數
            int day = gc.get(Calendar.DAY_OF_MONTH);
            System.out.printf("%3d", day);

            // 用“*”標記今天
            if (day == today) {
                System.out.print("*");
            } else {
                System.out.print(" ");
            }

            gc.add(Calendar.DAY_OF_MONTH, 1);// 天數加1
            weekday = gc.get(Calendar.DAY_OF_WEEK);

            // 列印一週後換行
            if (weekday == firstDayOfWeek) {
                System.out.println();
            }
        } while (gc.get(Calendar.MONTH) == month);// 到下個月結束

    }

}