java日期处理

package tree;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
 
public class DateUtil {
 
	/**
	 * 将字符串转化为DATE
	 * 
	 * @param dtFormat
	 *            格式yyyy-MM-dd HH:mm:ss 或 yyyy-MM-dd或 yyyy-M-dd或 yyyy-M-d或
	 *            yyyy-MM-d或 yyyy-M-dd
	 * @param def
	 *            如果格式化失败返回null
	 * @return
	 */
	public static Date fmtStrToDate(String dtFormat) {
		if (dtFormat == null ) {
			return null;
		} 
		try {
			if (dtFormat.length() == 9 || dtFormat.length() == 8) {
				String[] dateStr = dtFormat.split("-");
				dtFormat = dateStr[0] + (dateStr[1].length() == 1 ? "-0" : "-") + dateStr[1] + (dateStr[2].length() == 1 ? "-0" : "-")+ dateStr[2];
			}
			if (dtFormat.length() != 10 & dtFormat.length() != 19)
				return null;
			if (dtFormat.length() == 10)
				dtFormat = dtFormat + " 00:00:00";
			SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
			return dateFormat.parse(dtFormat);
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}

	/**
	 * 
	 * Description:格式化日期,如果格式化失败返回def
	 * 
	 * @param dtFormat
	 * @param def
	 * @return
	 * @author ganliang
	 * @since：2008-2-15 下午05:01:37
	 */
	public static Date fmtStrToDate(String dtFormat, Date def) {
		Date d = fmtStrToDate(dtFormat);
		if (d == null)
			return def;
		return d;
	}

	/**
	 * 返回当日短日期型
	 * 
	 * @return
	 * @author ganliang
	 * @since：2008-2-15 下午05:03:13
	 */
	public static Date getToDay() {
		return toShortDate(new Date());
	}

	/**
	 * 
	 * Description:格式化日期,String字符串转化为Date
	 * 
	 * @param date
	 * @param dtFormat
	 *            例如:yyyy-MM-dd HH:mm:ss yyyyMMdd
	 * @return
	 * @author ganliang
	 * @since：2007-7-10 上午11:24:00
	 */
	public static String fmtDateToStr(Date date, String dtFormat) {
		if (date == null)
			return "";
		try {
			SimpleDateFormat dateFormat = new SimpleDateFormat(dtFormat);
			return dateFormat.format(date);
		} catch (Exception e) {
			e.printStackTrace();
			return "";
		}
	}

	/**
	 * Description:按指定格式 格式化日期
	 * 
	 * @param date
	 * @param dtFormat
	 * @return
	 * @author ganliang
	 * @since：2007-12-10 上午11:25:07
	 */
	public static Date fmtStrToDate(String date, String dtFormat) {
		try {
			SimpleDateFormat dateFormat = new SimpleDateFormat(dtFormat);
			return dateFormat.parse(date);
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}

	public static String fmtDateToYMDHM(Date date) {
		return fmtDateToStr(date, "yyyy-MM-dd HH:mm");
	}

	public static String fmtDateToYMD(Date date) {
		return fmtDateToStr(date, "yyyy-MM-dd");
	}

	public static String fmtDateToYM(Date date) {
		return fmtDateToStr(date, "yyyy-MM");
	}

	public static String fmtDateToM(Date date) {
		return fmtDateToStr(date, "MM");
	}

	/**
	 * 
	 * Description:只保留日期中的年月日
	 * 
	 * @param date
	 * @return
	 * @author ganliang
	 * @since：2007-12-10 上午11:25:50
	 */
	public static Date toShortDate(Date date) {
		String strD = fmtDateToStr(date, "yyyy-MM-dd");
		return fmtStrToDate(strD);
	}

	/**
	 * 
	 * Description:只保留日期中的年月日
	 * 
	 * @param date格式要求yyyy
	 *            -MM-dd……………………
	 * @return
	 * @author ganliang
	 * @since：2007-12-10 上午11:26:12
	 */
	public static Date toShortDate(String date) {
		if (date != null && date.length() >= 10) {
			return fmtStrToDate(date.substring(0, 10));
		} else
			return fmtStrToDate(date);
	}

	/**
	 * 求对日
	 * 
	 * @param countMonth
	 *            :月份的个数(几个月)
	 * @param flag
	 *            :true 求前countMonth个月的对日:false 求下countMonth个月的对日
	 * @return
	 */
	public static Date getCounterglow(int countMonth, boolean before) {
		Calendar ca = Calendar.getInstance();
		return getCounterglow(ca.getTime(), before ? -countMonth : countMonth);
	}

	/**
	 * 
	 * Description: 求对日 加月用+ 减月用-
	 * 
	 * @param date
	 * @param countMonth
	 * @return
	 * @since：2007-12-13 下午03:16:47
	 */
	public static Date getCounterglow(Date date, int num) {
		Calendar ca = Calendar.getInstance();
		ca.setTime(date);
		ca.add(Calendar.MONTH, num);
		return ca.getTime();
	}

	/**
	 * 
	 * Description:加一天
	 * 
	 * @param date
	 * @return
	 * @author ganliang
	 * @since：2007-12-13 下午02:57:38
	 */
	public static Date addDay(Date date) {
		Calendar cd = Calendar.getInstance();
		cd.setTime(date);
		cd.add(Calendar.DAY_OF_YEAR, 1);
		return cd.getTime();
	}

	/**
	 * 
	 * Description:判断一个日期是否为工作日(非周六周日)
	 * 
	 * @param date
	 * @return
	 * @author ganliang
	 * @since：2007-12-13 下午03:01:35
	 */
	public static boolean isWorkDay(Date date) {
		Calendar cd = Calendar.getInstance();
		cd.setTime(date);
		int dayOfWeek = cd.get(Calendar.DAY_OF_WEEK);
		if (dayOfWeek != Calendar.SUNDAY || dayOfWeek != Calendar.SATURDAY)
			return false;
		return true;
	}

	/**
	 * 
	 * Description:取一个月的最后一天
	 * 
	 * @param date1
	 * @return
	 * @author ganliang
	 * @since：2007-12-13 下午03:28:21
	 */
	public static Date getLastDayOfMonth(Date date1) {
		Calendar date = Calendar.getInstance();
		date.setTime(date1);
		date.set(Calendar.DAY_OF_MONTH, 1);
		date.add(Calendar.MONTH, 1);
		date.add(Calendar.DAY_OF_YEAR, -1);
		return toShortDate(date.getTime());
	}

	/**
	 * 求开始截至日期之间的天数差.
	 * 
	 * @param d1
	 *            开始日期
	 * @param d2
	 *            截至日期
	 * @return 返回相差天数
	 */
	public static int getDaysInterval(Date d1, Date d2) {
		if (d1 == null || d2 == null)
			return 0;
		Date[] d = new Date[2];
		d[0] = d1;
		d[1] = d2;
		Calendar[] cal = new Calendar[2];
		for (int i = 0; i < cal.length; i++) {
			cal[i] = Calendar.getInstance();
			cal[i].setTime(d[i]);
			cal[i].set(Calendar.HOUR_OF_DAY, 0);
			cal[i].set(Calendar.MINUTE, 0);
			cal[i].set(Calendar.SECOND, 0);
		}
		long m = cal[0].getTime().getTime();
		long n = cal[1].getTime().getTime();
		int ret = (int) Math.abs((m - n) / 1000 / 3600 / 24);
		return ret;
	}

	public static String getDayOfWeek(Date date) {
		Calendar cl = Calendar.getInstance();
		cl.setTime(date);
		return "周" + toChNumber(cl.get(Calendar.DAY_OF_WEEK) - 1);
	}

	/**
	 * 将数字转为中文。 "0123456789"->"〇一二三四五六七八九"
	 * 
	 * @param num
	 *            长度为1,'0'-'9'的字符串
	 * @return
	 */
	private static String toChNumber(int num) {
		final String str = "〇一二三四五六七八九";
		return str.substring(num, num + 1);
	}

	/**
	 * 
	 * Description:指定日期加或减days天
	 * 
	 * @param date1日期
	 * @param days天数
	 * @return
	 * @author ganliang
	 * @since：2007-12-17 下午03:47:12
	 */
	public static Date addDay(Date date1, int days) {
		Calendar date = Calendar.getInstance();
		date.setTime(date1);
		date.add(Calendar.DAY_OF_YEAR, days);
		return date.getTime();
	}

	/**
	 * 
	 * Description:指定日期加或减months月
	 * 
	 * @param date1
	 * @param months
	 * @return
	 * @author ganliang
	 * @since：2008-3-5 下午05:17:26
	 */
	public static Date addMonth(Date date1, int months) {
		Calendar date = Calendar.getInstance();
		date.setTime(date1);
		date.add(Calendar.MONTH, months);
		return date.getTime();
	}

	/**
	 * 
	 * Description:指定日期加或减years年
	 * 
	 * @param date1
	 * @param years
	 * @return
	 */
	public static Date addYear(Date date1, int years) {
		Calendar date = Calendar.getInstance();
		date.setTime(date1);
		date.add(Calendar.YEAR, years);
		return date.getTime();
	}

	/**
	 * 指定期间的开始日期
	 * 
	 * @param date
	 *            指定日期
	 * @param type
	 *            期间类型
	 * @param diff
	 *            与指定日期的范围
	 * @return
	 */
	public static Date getPeriodStart(Calendar date, int type, int diff) {
		date.add(type, diff * (-1));
		return date.getTime();
	}

	/**
	 * 指定期间的开始日期
	 * 
	 * @param date
	 *            指定日期
	 * @param type
	 *            期间类型
	 * @param diff
	 *            与指定日期的范围
	 * @return
	 */
	public static Date getPeriodStart(Date date, int type, int diff) {
		return getPeriodStart(dateToCalendar(date), type, diff);
	}

	/**
	 * 指定期间的结束日期
	 * 
	 * @param date
	 *            指定日期
	 * @param type
	 *            期间类型
	 * @param diff
	 *            与指定日期的范围
	 * @return
	 */
	public static Date getPeriodEnd(Calendar date, int type, int diff) {
		date.add(type, diff);
		return date.getTime();
	}

	/**
	 * 指定期间的结束日期
	 * 
	 * @param date
	 *            指定日期
	 * @param type
	 *            期间类型
	 * @param diff
	 *            与指定日期的范围
	 * @return
	 */
	public static Date getPeriodEnd(Date date, int type, int diff) {
		return getPeriodEnd(dateToCalendar(date), type, diff);
	}

	/**
	 * 指定日期所在星期的第一天
	 * 
	 * @param date
	 * @return
	 */
	public static Date getWeekStart(Date date) {
		Calendar cdate = dateToCalendar(date);
		cdate.set(Calendar.DAY_OF_WEEK, 2);
		return cdate.getTime();
	}

	/**
	 * 将java.util.Date类型转换成java.util.Calendar类型
	 * 
	 * @param date
	 * @return
	 */
	public static Calendar dateToCalendar(Date date) {
		Calendar cdate = Calendar.getInstance();
		cdate.setTime(date);
		return cdate;
	}

	/**
	 * 指定日期所在月的第一天
	 * 
	 * @param date
	 * @return
	 */
	public static Date getMonthStart(Date date) {
		Calendar cdate = dateToCalendar(date);
		cdate.set(Calendar.DAY_OF_MONTH, 1);
		return toShortDate(cdate.getTime());
	}

	/**
	 * 指定日期所在上月的第一天
	 * 
	 * @param date
	 * @return
	 */
	public static Date getLastMonthStart(Date date) {
		Calendar cdate = dateToCalendar(date);
		cdate.set(Calendar.DAY_OF_MONTH, 1);
		cdate.add(Calendar.MONTH, -1);
		return toShortDate(cdate.getTime());
	}

	/**
	 * 指定日期所在旬的第一天
	 * 
	 * @param date
	 * @return
	 */
	public static Date getTenDaysStart(Date date) {
		Calendar cdate = dateToCalendar(date);
		int day = cdate.get(Calendar.DAY_OF_MONTH) / 10 * 10 + 1;
		if (cdate.get(Calendar.DAY_OF_MONTH) % 10 == 0 || day == 31)
			day = day - 10;
		cdate.set(Calendar.DAY_OF_MONTH, day);
		return cdate.getTime();
	}

	/**
	 * 指定日期所在旬的最后一天
	 * 
	 * @param date
	 * @return
	 */
	public static Date getTenDaysEnd(Date date) {
		Calendar cdate = dateToCalendar(date);
		if (cdate.get(Calendar.DAY_OF_MONTH) / 10 == 2
				&& cdate.get(Calendar.DAY_OF_MONTH) != 20)
			return getLastDayOfMonth(date);
		else
			return addDay(getTenDaysStart(addDay(date, 10)), -1);
	}

	/**
	 * 指定日期所在年的第一天
	 * 
	 * @param date
	 * @return
	 */
	public static Date getYearStart(Date date) {
		Calendar cdate = dateToCalendar(date);
		cdate.set(Calendar.DAY_OF_YEAR, 1);
		return cdate.getTime();
	}

	/**
	 * 指定日期所在季度的第一天
	 * 
	 * @param date
	 * @return
	 */
	public static Date getQuarterStart(Date date) {
		Calendar cdate = dateToCalendar(date);
		int month = (cdate.get(Calendar.MONTH) / 3) * 3;
		cdate.set(Calendar.MONTH, month);
		return getMonthStart(cdate.getTime());
	}

	/**
	 * 指定日期返回带中文的字符串（目前为年月日类型，之后补充）
	 * 
	 * @param date
	 * @param format
	 * @return
	 */
	public static String dateToStringByChinese(String format, Date date) {
		String dateString = fmtDateToStr(date, format);
		String[] dateStringArray = dateString.split("-");
		if ("yyyy-MM-dd".equals(format)) {
			dateString = dateStringArray[0] + "年" + dateStringArray[1] + "月"
					+ dateStringArray[2] + "日";
		} else if ("yyyy-MM".equals(format)) {
			dateString = dateStringArray[0] + "年" + dateStringArray[1] + "月";
		}
		return dateString;
	}

	public static Date getLastDayOfYear(Date date) {
		SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");
		String years = dateFormat.format(date);
		years += "-12-31";
		Date returnDate = fmtStrToDate(years);
		return toShortDate(returnDate);
	}

	/**
	 * 计算两个日期之间相差的月数
	 * 
	 * @param date1
	 * @param date2
	 * @return
	 */
	public static int getMonths(Date date1, Date date2) {
		int iMonth = 0;
		int flag = 0;
		try {
			Calendar objCalendarDate1 = Calendar.getInstance();
			objCalendarDate1.setTime(date1);

			Calendar objCalendarDate2 = Calendar.getInstance();
			objCalendarDate2.setTime(date2);

			if (objCalendarDate2.equals(objCalendarDate1))
				return 0;
			if (objCalendarDate1.after(objCalendarDate2)) {
				Calendar temp = objCalendarDate1;
				objCalendarDate1 = objCalendarDate2;
				objCalendarDate2 = temp;
			}
			if (objCalendarDate2.get(Calendar.DAY_OF_MONTH) < objCalendarDate1.get(Calendar.DAY_OF_MONTH))
				flag = 1;

			if (objCalendarDate2.get(Calendar.YEAR) > objCalendarDate1.get(Calendar.YEAR))
				iMonth = ((objCalendarDate2.get(Calendar.YEAR) - objCalendarDate1.get(Calendar.YEAR))* 12 + objCalendarDate2.get(Calendar.MONTH) - flag)- objCalendarDate1.get(Calendar.MONTH);
			else
				iMonth = objCalendarDate2.get(Calendar.MONTH) - objCalendarDate1.get(Calendar.MONTH) - flag;

		} catch (Exception e) {
			e.printStackTrace();
		}
		return iMonth;
	}

	/**
	 * 指定日期上一个旬的第一天
	 */
	public static Date getLastTenStartDate(Date date) {
		Date returnDate = DateUtil.toShortDate(date);
		returnDate = DateUtil.getTenDaysStart(date);
		returnDate = DateUtil.addDay(returnDate, -1);
		returnDate = DateUtil.getTenDaysStart(returnDate);
		return DateUtil.toShortDate(returnDate);
	}

	/**
	 * 指定日期上一个旬的最后一天
	 */
	public static Date getLastTenEndDate(Date date) {
		Date returnDate = DateUtil.toShortDate(date);
		returnDate = DateUtil.getTenDaysStart(date);
		returnDate = DateUtil.addDay(returnDate, -1);
		return DateUtil.toShortDate(returnDate);
	}

	/**
	 * 指定日期上个月第一天
	 */
	public static Date getLastMonthStartDate(Date date) {
		Date returnDate = DateUtil.toShortDate(date);
		returnDate = DateUtil.getLastMonthStart(date);
		return DateUtil.toShortDate(returnDate);
	}

	/**
	 * 指定日期上个月最后一天
	 */
	public static Date getLastMonthEndDate(Date date) {
		Date returnDate = DateUtil.toShortDate(date);
		returnDate = DateUtil.getMonthStart(date);
		returnDate = DateUtil.addDay(returnDate, -1);
		return DateUtil.toShortDate(returnDate);
	}

	public static void main(String args[]) {
		Date date =  DateUtil.fmtStrToDate("2200-02-28 23:11:59");
		System.out.println(DateUtil.fmtDateToYMD(DateUtil.addDay(date,-1)));
		System.out.println(DateUtil.fmtDateToYMD(DateUtil.addDay(date,2)));
		
		Date date1= DateUtil.fmtStrToDate("2012-01-11");
		Date date2= DateUtil.fmtStrToDate("2011-11-31");
		System.out.println(DateUtil.getMonths(date1, date2));
		
		System.out.println(DateUtil.getLastMonthEndDate(date1));
		System.out.println(DateUtil.fmtDateToYMD(DateUtil.getLastMonthStartDate(date1)));
	}
}