Java 日期类算法 转

对日期的操作主要可以用
java.text.SimpleDateFormat
java.util.Calendar
java.util.Date
进行操作，也可以用apacle commons中的commons-lang包下的
org.apache.commons.lang.time.DateUtils来对日期就行操作
下面写的一些操作日期的的工具类

import java.text.DateFormat;   
import java.text.ParseException;   
import java.text.SimpleDateFormat;   
import java.util.ArrayList;   
import java.util.Calendar;   
import java.util.Date;   
import java.util.LinkedHashSet;   
import java.util.List;   
import java.util.Locale;   
.import java.util.Set;   
import org.apache.log4j.Logger;   
 
public class DateUtils {   
   private static final Logger log = Logger.getLogger(DateUtils.class);   
 
   /**  
    * 将字符串日期转换为Date  
    *   
    * @param s  
    * @return  
    */  
   public static Date convertToDate(String s) {   
       DateFormat df;   
       if (s == null) {   
           return null;   
       }   
       if (s.contains(":")) {   
           try {   
               df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");   
               return df.parse(s);   
           } catch (Exception e) {   
               log.error(e);   
               return null;   
           }   
       } else {   
           try {   
               df = new SimpleDateFormat("yyyy-MM-dd");   
               return df.parse(s);   
           } catch (Exception e) {   
               log.error(e);   
               return null;   
           }   
       }   
   }   
 
   /**  
    * 将Date转换为String  
    *   
    * @param d  
    * @return  
    */  
   public static String formatDate(Date d) {   
       if (d == null) {   
           return null;   
       }   
       SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");   
       try {   
           return sdf.format(d);   
       } catch (Exception e) {   
           log.error(e);   
           return null;   
       }   
   }   
 
   /**  
    * 将Date转换为String  
    *   
    * @param d  
    * @return  
    */  
   public static String formatTime(Date d) {   
       if (d == null) {   
           return null;   
       }   
       SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");   
       try {   
           return sdf.format(d);   
       } catch (Exception e) {   
           log.error(e);   
           return null;   
       }   
   }   
 
   public static String formatTimeHHmm(Date d) {   
       if (d == null) {   
           return null;   
       }   
       SimpleDateFormat sdf = new SimpleDateFormat("HH:mm");   
       try {   
           return sdf.format(d);   
       } catch (Exception e) {   
           log.error(e);   
           return null;   
       }   
   }   
 
   /**  
    * 将Date按locale转换为String  
    *   
     * @param d  
     * @return  
     */  
    public static String formatLocaleDate(Date d, Locale locale) {   
        if (d == null) {   
            return null;   
        }   
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd", locale);   
        try {   
            return sdf.format(d);   
        } catch (Exception e) {   
            log.error(e);   
            return null;   
        }   
    }   
  
    /**  
     * 将Date按locale转换为String  
     *   
     * @param d  
     * @return  
     */  
    public static String formatLocaleDateTime(Date d, Locale locale) {   
        if (d == null) {   
            return null;   
        }   
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", locale);   
        try {   
            return sdf.format(d);   
        } catch (Exception e) {   
            log.error(e);   
            return null;   
        }   
    }   
  
    /**  
     * 将Date转换为String  
     *   
     * @param d  
     * @return  
     */  
    public static String formatDateTime(Date d) {   
        if (d == null) {   
            return null;   
        }   
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");   
        try {   
            return sdf.format(d);   
        } catch (Exception e) {   
            log.error(e);   
            return null;   
        }   
    }   
  
    /**  
     * 得到每月多少天  
     *   
     * @param year  
     * @param month  
     * @return 返回 -1表示异常  
     */  
    public static int getDaysByMonth(int year, int month) {   
        if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12) {   
            return 31;   
        }   
  
        if (month == 4 || month == 6 || month == 9 || month == 11)   
            return 30;   
  
        if (month == 2) {   
            if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0) {   
                return 29;   
            } else {   
                return 28;   
            }   
        }   
        return -1;   
    }   
  
    public static String dayOfWeekByDayNum(int x) {   
        String str = "周日";   
        if (x == 7) {   
            str = "周六";   
        } else if (x == 6) {   
            str = "周五";   
        } else if (x == 5) {   
            str = "周四";   
        } else if (x == 4) {   
            str = "周三";   
        } else if (x == 3) {   
            str = "周二";   
        } else if (x == 2) {   
            str = "周一";   
        }   
        return str;   
    }   
  
    /**  
     * 据年、月、日，获得当天为周几  
     *   
     * @param year  
     * @param month  
     * @param day  
     * @return  
     */  
    public static int getWeekByDate(int year, int month, int day) {   
        Calendar c = Calendar.getInstance();   
        c.set(Calendar.YEAR, year);   
        c.set(Calendar.MONTH, month - 1);   
        c.set(Calendar.DAY_OF_MONTH, day);   
  
        return c.get(Calendar.DAY_OF_WEEK);   
    }   
  
    /**  
     * 得到现在是这个周的第几天  
     *   
     * @return  
     */  
    public static int getWeekByDate() {   
        Calendar c = Calendar.getInstance();   
        return c.get(Calendar.DAY_OF_WEEK);   
    }   
  
    public static List<String> monthDiff(Date date1, Date date2) throws Exception {   
        List<String> monthList = new ArrayList<String>();   
  
        if (DateUtils.dateDiff(date1, date2) < 0) {   
            return monthList;   
        }   
  
        Calendar calendar1 = Calendar.getInstance();   
        Calendar calendar2 = Calendar.getInstance();   
        calendar1.setTime(date1);   
        calendar2.setTime(date2);   
        while (DateUtils.dateDiff(calendar1.getTime(), calendar2.getTime()) >= 0) {   
            monthList.add(DateUtils.formatDate(calendar1.getTime()));   
            calendar1.set(Calendar.DAY_OF_MONTH, 1);   
            calendar1.set(Calendar.MONTH, calendar1.get(Calendar.MONTH) + 1);   
        }   
        if (monthList.size() > 0) {   
            monthList.remove(monthList.size() - 1);   
            monthList.add(DateUtils.formatDate(date2));   
        }   
  
        return monthList;   
    }   
  
    /**  
     * 计算两个日期之间相差多少天  
     *   
     * @param date1  
     * @param date2  
     * @return  
     */  
    public static int dateDiff(Date date1, Date date2) {   
        Calendar calendar1 = Calendar.getInstance();   
        Calendar calendar2 = Calendar.getInstance();   
        calendar1.setTime(date1);   
        calendar2.setTime(date2);   
        long increaseDate = (calendar2.getTimeInMillis() - calendar1.getTimeInMillis()) / 1000 / 60 / 60 / 24;   
        if (((calendar2.getTimeInMillis() - calendar1.getTimeInMillis()) % (1000 * 60 * 60 * 24)) > 0) {   
            increaseDate = increaseDate + 1;   
        }   
        return (int) increaseDate;   
    }   
  
    /**  
     * 取得两天之间的天数  
     *   
     * @param start  
     * @param end  
     * @return  
     */  
    public static int daysBetween(Date start, Date end) {   
        // return date1.getTime() / (24*60*60*1000) - date2.getTime() /   
        // (24*60*60*1000);   
        String formatDate = formatDate(start);   
        Date convertStartDate = convertToDate(formatDate);   
        formatDate = formatDate(end);   
        Date convertEndDate = convertToDate(formatDate);   
        return (int) (convertEndDate.getTime() / 86400000 - convertStartDate.getTime() / 86400000); // 用立即数，减少乘法计算的开销   
    }   
  
    /**  
     * 取得两天之间的日期数组，包含开始日期与结束日期  
     *   
     * @param startDateStr  
     *            开始日期  
     * @param endDateStr  
     *            结束日期  
     * @return Date[] 日期数组  
     */  
    public static Date[] getBetweenTwoDayArray(String startDateStr, String endDateStr) {   
        Date startDate = formatDateYyyyMmDd(startDateStr);   
        int dateNum = Integer.parseInt(getDaysBetweenTwoDates(startDateStr, endDateStr)) + 1;   
        Date[] dataArray = new Date[dateNum];   
        for (int i = 0; i < dateNum; i++) {   
            dataArray[i] = startDate;   
            startDate = org.apache.commons.lang.time.DateUtils.addDays(startDate, 1);   
        }   
        return dataArray;   
    }   
  
    /**  
     * 把日期字符串格式化为日期类型  
     *   
     * @param datetext  
     * @return  
     */  
    public static Date formatDateYyyyMmDd(String datetext) {   
        try {   
            SimpleDateFormat df;   
            if (datetext == null || "".equals(datetext.trim())) {   
                return null;   
            }   
            datetext = datetext.replaceAll("/", "-");   
            df = new SimpleDateFormat("yyyy-MM-dd");   
            Date date = df.parse(datetext);   
            return date;   
        } catch (Exception e) {   
            e.printStackTrace();   
            return null;   
        }   
    }   
  
    /*  
     * 两个日期之间相隔天数的共通 author:jerry.ji date:08-03-06  
     *   
     * @param from 開始時間  
     *   
     * @param to　終了時間  
     *   
     * @return　天数  
     */  
    public static String getDaysBetweenTwoDates(String dateFrom, String dateEnd) {   
        Date dtFrom = null;   
        Date dtEnd = null;   
        dtFrom = string2Date(dateFrom, "yyyy-MM-dd");   
        dtEnd = string2Date(dateEnd, "yyyy-MM-dd");   
        long begin = dtFrom.getTime();   
        long end = dtEnd.getTime();   
        long inter = end - begin;   
        if (inter < 0) {   
            inter = inter * (-1);   
        }   
        long dateMillSec = 24 * 60 * 60 * 1000;   
  
        long dateCnt = inter / dateMillSec;   
  
        long remainder = inter % dateMillSec;   
  
        if (remainder != 0) {   
            dateCnt++;   
        }   
        return String.valueOf(dateCnt);   
    }   
  
    /**  
     * 把日期字符串格式化为日期类型  
     *   
     * @param datetext  
     *            日期字符串  
     * @param format  
     *            日期格式，如果不传则使用"yyyy-MM-dd HH:mm:ss"格式  
     * @return  
     */  
    public static Date string2Date(String datetext, String format) {   
        try {   
            SimpleDateFormat df;   
            if (datetext == null || "".equals(datetext.trim())) {   
                return new Date();   
            }   
            if (format != null) {   
                df = new SimpleDateFormat(format);   
            } else {   
                datetext = datetext.replaceAll("/", "-");   
                df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");   
            }   
  
            Date date = df.parse(datetext);   
  
            return date;   
  
        }   
  
        catch (Exception e) {   
            e.printStackTrace();   
            return new Date();   
        }   
    }   
  
    public static String formatDate(Date date, String format) {   
        try {   
            if (format != null && !"".equals(format) && date != null) {   
                SimpleDateFormat formatter = new SimpleDateFormat(format);   
                return formatter.format(date);   
            }   
        } catch (Exception e) {   
            return "";   
        }   
        return "";   
    }   
  
    /**  
     * 算出两个日期中所包含的月份  
     *   
     * @param fromDate  
     * @param toDate  
     * @return  
     */  
    public static Set<String> getMonthBetweenTwoDate(Date fromDate, Date toDate) {   
        long begin = fromDate.getTime();   
        long end = toDate.getTime();   
        long inter = end - begin;   
        if (inter < 0) {   
            inter = inter * (-1);   
        }   
        long dateMillSec = 86400000;   
        long dateCnt = inter / dateMillSec;   
        long remainder = inter % dateMillSec;   
        if (remainder != 0) {   
            dateCnt++;   
        }   
        Set<String> set = new LinkedHashSet<String>();   
        Calendar cl = Calendar.getInstance();   
        cl.setTime(fromDate);   
        cl.set(Calendar.HOUR_OF_DAY, 0);   
        cl.set(Calendar.MINUTE, 0);   
        cl.set(Calendar.SECOND, 0);   
        cl.set(Calendar.MILLISECOND, 0);   
        set.add(getDateyyyyMM(cl.getTime()));   
        for (int i = 1; i <= dateCnt; i++) {   
            cl.add(Calendar.DAY_OF_YEAR, 1);   
            set.add(getDateyyyyMM(cl.getTime()));   
        }   
        return set;   
    }   
  
    /**  
     * 得到yyyyMM的年月  
     *   
     * @param date  
     * @return  
     */  
    public static String getDateyyyyMM(Date date) {   
        SimpleDateFormat df = new SimpleDateFormat("yyyyMM");   
        return df.format(date);   
    }   
  
    /**  
     * 得到yyyyMM的年月  
     *   
     * @param date  
     * @return  
     */  
    public static String getDateyyyyMMdd(Date date) {   
        SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd");   
        return df.format(date);   
    }   
  
    /**  
     * 得到一月的最大天数  
     *   
     * @param date  
     * @return  
     */  
    public static int getMonthsMaxDay(Date date) {   
        Calendar cal1 = Calendar.getInstance();   
        cal1.setTime(date);   
        return cal1.getActualMaximum(cal1.DAY_OF_MONTH);   
    }   
  
    public static Date parseDateyyyyMM(String month) {   
        SimpleDateFormat df = new SimpleDateFormat("yyyyMM");   
        try {   
            return df.parse(month);   
        } catch (ParseException e) {   
        }   
        return null;   
    }   
  
    public static Date parseDateyyyyMMdd(String date) {   
        SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd");   
        try {   
            return df.parse(date);   
        } catch (ParseException e) {   
        }   
        return null;   
    }   
  
    /**  
     * 根据两个日期，算出某个月份的第一天，或者最后一天  
     *   
     * @param dateFrom  
     * @param dateTo  
     * @param month  
     * @param flag  
     * @return  
     */  
    public static int getDayBetweenDateStartOrEnd(Date dateFrom, Date dateTo, Date month, String flag) {   
        if (dateFrom.getTime() > dateTo.getTime()) {   
            Date temp = dateFrom;   
            dateFrom = dateTo;   
            dateTo = temp;   
        }   
        if (getDateyyyyMM(month).compareTo(getDateyyyyMM(dateFrom)) > 0  
                && getDateyyyyMM(month).compareTo(getDateyyyyMM(dateTo)) < 0) {   
            if ("start".equals(flag))   
                return 1;   
            return getMonthsMaxDay(month);   
        } else if (getDateyyyyMM(month).compareTo(getDateyyyyMM(dateFrom)) == 0  
                && getDateyyyyMM(month).compareTo(getDateyyyyMM(dateTo)) < 0) {   
            if ("start".equals(flag))   
                return getDayOfMonth(dateFrom);   
            return getMonthsMaxDay(month);   
        } else if (getDateyyyyMM(month).compareTo(getDateyyyyMM(dateFrom)) > 0  
                && getDateyyyyMM(month).compareTo(getDateyyyyMM(dateTo)) == 0) {   
            if ("start".equals(flag))   
                return 1;   
            return getDayOfMonth(dateTo);   
        } else {   
            if ("start".equals(flag))   
                return getDayOfMonth(dateFrom);   
            return getDayOfMonth(dateTo);   
        }   
  
    }   
  
    /**  
     * 根据一个日期，算出是这个月中的第几天  
     *   
     * @param date  
     * @return  
     */  
    public static int getDayOfMonth(Date date) {   
        Calendar cal1 = Calendar.getInstance();   
        cal1.setTime(date);   
        return cal1.get(Calendar.DAY_OF_MONTH);   
    }   
  
    /**  
     * 取出一个月中某天的日期  
     *   
     * @param month  
     * @param num  
     * @return  
     */  
    public static Date getDateOfMonthByNum(String month, int num) {   
        Calendar cl = Calendar.getInstance();   
        cl.setTime(parseDateyyyyMM(month));   
        cl.set(Calendar.HOUR_OF_DAY, 0);   
        cl.set(Calendar.MINUTE, 0);   
        cl.set(Calendar.SECOND, 0);   
        cl.set(Calendar.MILLISECOND, 0);   
        cl.add(Calendar.DAY_OF_YEAR, num - 1);   
        return cl.getTime();   
    }   
  
    /**  
     * 得到本周第一天日期  
     *   
     * @author vincent.shan  
     * @return  
     */  
    public static Date getCurrentWeekMonday() {   
  
        Calendar cal = Calendar.getInstance();   
        cal.set(Calendar.HOUR_OF_DAY, 0);   
        cal.set(Calendar.MINUTE, 0);   
        cal.set(Calendar.SECOND, 0);   
        cal.set(Calendar.MILLISECOND, 0);   
        int index = cal.get(Calendar.DAY_OF_WEEK);   
        // 转成中国的习惯,如果是第一天,则转化为第七天(星期天外国为一周的第一天,而中国为每周的最后一天)   
        if (index == 1)   
            index = 8;   
        cal.add(Calendar.DATE, -(index - 2));   
        return cal.getTime();   
  
    }   
  
    /**  
     * 得到本周最后一天的日期  
     *   
     * @author vincent.shan  
     * @return  
     */  
    public static Date getCurrentWeekSaturday() {   
        Calendar cal = Calendar.getInstance();   
        cal.set(Calendar.HOUR_OF_DAY, 0);   
        cal.set(Calendar.MINUTE, 0);   
        cal.set(Calendar.SECOND, 0);   
        cal.set(Calendar.MILLISECOND, 0);   
        int index = cal.get(Calendar.DAY_OF_WEEK);   
        if (index == 1)   
            index = 8;   
        cal.add(Calendar.DATE, -(index - 2));   
        cal.add(Calendar.DATE, 6);   
        return cal.getTime();   
    }   
  
    /**  
     * 从指定日期移动一定的天数  
     *   
     * @param date  
     * @param day  
     * @return  
     */  
    public static Date moveDay(Date date, int day) {   
        Calendar cal = Calendar.getInstance();   
        cal.setTime(date);   
        cal.set(Calendar.HOUR_OF_DAY, 0);   
        cal.set(Calendar.MINUTE, 0);   
        cal.set(Calendar.SECOND, 0);   
        cal.set(Calendar.MILLISECOND, 0);   
        cal.add(Calendar.DAY_OF_MONTH, day);   
        return cal.getTime();   
    }   
  
    /**  
     * 从当天日期移动一定的月数  
     *   
     * @param month  
     * @return  
     */  
  
    public static Date getMoveMonthDate(int month) {   
        Date nowDate = new Date();   
        Calendar cl = Calendar.getInstance();   
        cl.setTime(nowDate);   
        cl.add(Calendar.MONDAY, month - 1);   
        Date date1 = cl.getTime();   
        return date1;   
    }   
  
    /**  
     * 得到昨天  
     *   
     * @param date  
     * @param day  
     * @return  
     */  
    public static Date getYesterday() {   
        Calendar cal = Calendar.getInstance();   
  
        cal.set(Calendar.HOUR_OF_DAY, 0);   
        cal.set(Calendar.MINUTE, 0);   
        cal.set(Calendar.SECOND, 0);   
        cal.set(Calendar.MILLISECOND, 0);   
        cal.add(Calendar.DAY_OF_MONTH, -1);   
        return cal.getTime();   
    }   
  
    /**  
     * 根据某个日期，返回本月第一天  
     *   
     * @param date  
     *            任何一天  
     * @return Date 当月第一天  
     * */  
    public static Date getMonthsFirstDay(Date date) {   
        Calendar cal = Calendar.getInstance();   
        cal.setTime(date);   
        cal.set(Calendar.DATE, 1);   
        cal.set(Calendar.HOUR_OF_DAY, 0);   
        cal.set(Calendar.MINUTE, 0);   
        cal.set(Calendar.SECOND, 0);   
        cal.set(Calendar.MILLISECOND, 0);   
        return cal.getTime();   
    }   
  
    /**  
     * 根据某个日期，返回本月最后一天  
     *   
     * @param date  
     *            任何一天  
     * @return Date 当月第一天  
     * */  
    public static Date getMonthsLastDay(Date date) {   
        Calendar cal = Calendar.getInstance();   
        cal.setTime(date);   
        cal.set(Calendar.DATE, 1);   
        cal.set(Calendar.HOUR_OF_DAY, 0);   
        cal.set(Calendar.MINUTE, 0);   
        cal.set(Calendar.SECOND, 0);   
        cal.set(Calendar.MILLISECOND, 0);   
        cal.add(Calendar.MONTH, 1);   
        cal.add(Calendar.DATE, -1);   
        return cal.getTime();   
    }   
  
    public static Set<String> getDayList(Date startDate, Date endDate) {   
        long begin = startDate.getTime();   
        long end = endDate.getTime();   
        long inter = end - begin;   
        if (inter < 0) {   
            inter = inter * (-1);   
        }   
        long dateMillSec = 86400000;   
        long dateCnt = inter / dateMillSec;   
        Set<String> set = new LinkedHashSet<String>();   
        Calendar cl = Calendar.getInstance();   
        cl.setTime(startDate);   
        cl.set(Calendar.HOUR_OF_DAY, 0);   
        cl.set(Calendar.MINUTE, 0);   
        cl.set(Calendar.SECOND, 0);   
        cl.set(Calendar.MILLISECOND, 0);   
        set.add(getDateyyyyMMdd(cl.getTime()));   
        for (int i = 1; i <= dateCnt; i++) {   
            cl.add(Calendar.DAY_OF_YEAR, 1);   
            set.add(getDateyyyyMMdd(cl.getTime()));   
        }   
        set.add(getDateyyyyMMdd(endDate));   
        return set;   
    }   
  
    /**  
     * 功能：取得两个日期中最小的日期,如果两个日期参数都为null则返回null  
     *   
     * @author irvshan  
     *   
     * @param date1  
     * @param date2  
     * @return Date or null  
     */  
    public static Date getMinimizeDate(Date date1, Date date2) {   
        if (date1 == null) {   
            return date2;   
        }   
        if (date2 == null) {   
            return date1;   
        }   
        if (date1.compareTo(date2) > 0) {   
            return date2;   
        }   
        return date1;   
    }   
  
    /**  
     * 功能：取得两个日期中最大的日期,如果两个日期参数都为null则返回null  
     *   
     * @author irvshan  
     *   
     * @param date1  
     * @param date2  
     * @return Date or null  
     */  
    public static Date getMaxmizeDate(Date date1, Date date2) {   
        if (date1 == null) {   
            return date2;   
        }   
        if (date2 == null) {   
            return date1;   
        }   
        if (date1.compareTo(date2) < 0) {   
            return date2;   
        }   
        return date1;   
    }   
  
    public static int getDayofWeek(Date date, int day) {   
        Calendar calendar = Calendar.getInstance();   
        calendar.setTime(date);   
        calendar.set(Calendar.HOUR_OF_DAY, 0);   
        calendar.set(Calendar.MINUTE, 0);   
        calendar.set(Calendar.SECOND, 0);   
        calendar.set(Calendar.MILLISECOND, 0);   
        calendar.set(Calendar.DAY_OF_MONTH, calendar.get(Calendar.DAY_OF_MONTH) + day - 1);   
        return calendar.get(Calendar.DAY_OF_WEEK);   
    }   
  
    /**  
     * 把date1的小时，分钟，秒换成date2的小时，分钟，秒,返回换值后的date1  
     *   
     * @param date1  
     * @param date2  
     * @return  
     */  
    public static Date changeTheHourMinuteSecond(Date date1, Date date2) {   
        Calendar cl1 = Calendar.getInstance();   
        cl1.setTime(date1);   
        cl1.set(Calendar.HOUR_OF_DAY, 0);   
        cl1.set(Calendar.MINUTE, 0);   
        cl1.set(Calendar.SECOND, 0);   
  
        Calendar cl2 = Calendar.getInstance();   
        cl2.setTime(date2);   
        cl1.set(Calendar.HOUR_OF_DAY, cl2.get(Calendar.HOUR_OF_DAY));   
        cl1.set(Calendar.MINUTE, cl2.get(Calendar.MINUTE));   
        cl1.set(Calendar.SECOND, cl2.get(Calendar.SECOND));   
  
        return cl1.getTime();   
    }   
  
    public static void main(String[] args) {   
  
    }   
  
}