java計算指定日期的農歷代碼

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class Lunar {
    private int year;
    private int month;
    private int day;
    private boolean leap;
    final static String chineseNumber[] = { "一", "二", "三", "四", "五", "六", "七",
            "八", "九", "十", "十一", "十二" };
    static SimpleDateFormat chineseDateFormat = new SimpleDateFormat(
            "yyyy年MM月dd日");
    final static long[] lunarInfo = new long[] { 0x04bd8, 0x04ae0, 0x0a570,
            0x054d5, 0x0d260, 0x0d950, 0x16554, 0x056a0, 0x09ad0, 0x055d2,
            0x04ae0, 0x0a5b6, 0x0a4d0, 0x0d250, 0x1d255, 0x0b540, 0x0d6a0,
            0x0ada2, 0x095b0, 0x14977, 0x04970, 0x0a4b0, 0x0b4b5, 0x06a50,
            0x06d40, 0x1ab54, 0x02b60, 0x09570, 0x052f2, 0x04970, 0x06566,
            0x0d4a0, 0x0ea50, 0x06e95, 0x05ad0, 0x02b60, 0x186e3, 0x092e0,
            0x1c8d7, 0x0c950, 0x0d4a0, 0x1d8a6, 0x0b550, 0x056a0, 0x1a5b4,
            0x025d0, 0x092d0, 0x0d2b2, 0x0a950, 0x0b557, 0x06ca0, 0x0b550,
            0x15355, 0x04da0, 0x0a5d0, 0x14573, 0x052d0, 0x0a9a8, 0x0e950,
            0x06aa0, 0x0aea6, 0x0ab50, 0x04b60, 0x0aae4, 0x0a570, 0x05260,
            0x0f263, 0x0d950, 0x05b57, 0x056a0, 0x096d0, 0x04dd5, 0x04ad0,
            0x0a4d0, 0x0d4d4, 0x0d250, 0x0d558, 0x0b540, 0x0b5a0, 0x195a6,
            0x095b0, 0x049b0, 0x0a974, 0x0a4b0, 0x0b27a, 0x06a50, 0x06d40,
            0x0af46, 0x0ab60, 0x09570, 0x04af5, 0x04970, 0x064b0, 0x074a3,
            0x0ea50, 0x06b58, 0x055c0, 0x0ab60, 0x096d5, 0x092e0, 0x0c960,
            0x0d954, 0x0d4a0, 0x0da50, 0x07552, 0x056a0, 0x0abb7, 0x025d0,
            0x092d0, 0x0cab5, 0x0a950, 0x0b4a0, 0x0baa4, 0x0ad50, 0x055d9,
            0x04ba0, 0x0a5b0, 0x15176, 0x052b0, 0x0a930, 0x07954, 0x06aa0,
            0x0ad50, 0x05b52, 0x04b60, 0x0a6e6, 0x0a4e0, 0x0d260, 0x0ea65,
            0x0d530, 0x05aa0, 0x076a3, 0x096d0, 0x04bd7, 0x04ad0, 0x0a4d0,
            0x1d0b6, 0x0d250, 0x0d520, 0x0dd45, 0x0b5a0, 0x056d0, 0x055b2,
            0x049b0, 0x0a577, 0x0a4b0, 0x0aa50, 0x1b255, 0x06d20, 0x0ada0 };

// ====== 傳回農歷 y年的總天數
final private static int yearDays(int y) {
    int i, sum = 348;
    for (i = 0x8000; i > 0x8; i >>= 1) {
        if ((lunarInfo[y - 1900] & i) != 0)
            sum += 1;
    }
    return (sum + leapDays(y));
}

// ====== 傳回農歷 y年閏月的天數
final private static int leapDays(int y) {
    if (leapMonth(y) != 0) {
        if ((lunarInfo[y - 1900] & 0x10000) != 0)
            return 30;
        else
            return 29;
    } else
        return 0;
}

// ====== 傳回農歷 y年閏哪個月 1-12 , 沒閏傳回 0
final private static int leapMonth(int y) {
    return (int) (lunarInfo[y - 1900] & 0xf);
}

// ====== 傳回農歷 y年m月的總天數
final private static int monthDays(int y, int m) {
    if ((lunarInfo[y - 1900] & (0x10000 >> m)) == 0)
        return 29;
    else
        return 30;
}

// ====== 傳回農歷 y年的生肖
final public String animalsYear() {
    final String[] Animals = new String[] { "鼠", "牛", "虎", "兔", "龍", "蛇",
            "馬", "羊", "猴", "雞", "狗", "豬" };
    return Animals[(year - 4) % 12];
}

// ====== 傳入 月日的offset 傳回干支, 0=甲子
final private static String cyclicalm(int num) {
    final String[] Gan = new String[] { "甲", "乙", "丙", "丁", "戊", "己", "庚",
            "辛", "壬", "癸" };
    final String[] Zhi = new String[] { "子", "丑", "寅", "卯", "辰", "巳", "午",
            "未", "申", "酉", "戌", "亥" };
    return (Gan[num % 10] + Zhi[num % 12]);
}

// ====== 傳入 offset 傳回干支, 0=甲子
final public String cyclical() {
    int num = year - 1900 + 36;
    return (cyclicalm(num));
}

/** */
/**
 * 　　* 傳出y年m月d日對應的農歷. 　　* yearCyl3:農歷年與1864的相差數 ? 　　*
 * monCyl4:從1900年1月31日以來,閏月數 　　* dayCyl5:與1900年1月31日相差的天數,再加40 ? 　　* @param
 * cal 　　* @return 　　
 */
public Lunar(Calendar cal) {
    @SuppressWarnings("unused")
    int yearCyl, monCyl, dayCyl;
    int leapMonth = 0;
    Date baseDate = null;
    try {
        baseDate = chineseDateFormat.parse("1900年1月31日");
    } catch (ParseException e) {
        e.printStackTrace(); // To change body of catch statement use
                                // Options | File Templates.
    }
    // 求出和1900年1月31日相差的天數
    int offset = (int) ((cal.getTime().getTime() - baseDate.getTime()) / 86400000L);
    dayCyl = offset + 40;
    monCyl = 14;
    // 用offset減去每農歷年的天數
    // 計算當天是農歷第幾天
    // i最終結果是農歷的年份
    // offset是當年的第幾天
    int iYear, daysOfYear = 0;
    for (iYear = 1900; iYear < 2050 && offset > 0; iYear++) {
        daysOfYear = yearDays(iYear);
        offset -= daysOfYear;
        monCyl += 12;
    }
    if (offset < 0) {
        offset += daysOfYear;
        iYear--;
        monCyl -= 12;
    }
    // 農歷年份
    year = iYear;
    yearCyl = iYear - 1864;
    leapMonth = leapMonth(iYear); // 閏哪個月,1-12
    leap = false;
    // 用當年的天數offset,逐個減去每月（農歷）的天數，求出當天是本月的第幾天
    int iMonth, daysOfMonth = 0;
    for (iMonth = 1; iMonth < 13 && offset > 0; iMonth++) {
        // 閏月
        if (leapMonth > 0 && iMonth == (leapMonth + 1) && !leap) {
            --iMonth;
            leap = true;
            daysOfMonth = leapDays(year);
        } else
            daysOfMonth = monthDays(year, iMonth);
        offset -= daysOfMonth;
        // 解除閏月
        if (leap && iMonth == (leapMonth + 1))
            leap = false;
        if (!leap)
            monCyl++;
    }
    // offset為0時，并且剛才計算的月份是閏月，要校正
    if (offset == 0 && leapMonth > 0 && iMonth == leapMonth + 1) {
        if (leap) {
            leap = false;
        } else {
            leap = true;
            --iMonth;
            --monCyl;
        }
    }
    // offset小于0時，也要校正
    if (offset < 0) {
        offset += daysOfMonth;
        --iMonth;
        --monCyl;
    }
    month = iMonth;
    day = offset + 1;
}

public static String getChinaDayString(int day) {
    String chineseTen[] = { "初", "十", "廿", "卅" };
    int n = day % 10 == 0 ? 9 : day % 10 - 1;
    if (day > 30)
        return "";
    if (day == 10)
        return "初十";
    else
        return chineseTen[day / 10] + chineseNumber[n];
}

public String toString() {
    return year + "年" + (leap ? "閏" : "") + chineseNumber[month - 1] + "月"
            + getChinaDayString(day);
}

public static void main(String[] args) throws ParseException {
    Calendar today = Calendar.getInstance();
    today.setTime(chineseDateFormat.parse("2011年11月7日"));
    Lunar lunar = new Lunar(today);
    System.out.println("北京時間：" + chineseDateFormat.format(today.getTime())
            + "　農歷" + lunar);
}

}</pre>