本文实例为大家分享了Java工具类DateUtils的具体代码，供大家参考，具体内容如下

import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;/** * 描述:公共日期工具类 */public class DateUtils { public static String DATE_FORMAT = "yyyy-MM-dd"; public static String DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss"; public static String DATE_FORMAT_CHINESE = "yyyy年M月d日"; /** * 获取当前日期 * * * @return * */ public static String getCurrentDate() { String datestr = null; SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_FORMAT); datestr = df.format(new Date()); return datestr; } /** * 获取当前日期时间 * * * @return * */ public static String getCurrentDateTime() { String datestr = null; SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_TIME_FORMAT); datestr = df.format(new Date()); return datestr; } /** * 获取当前日期时间 * * * @return * */ public static String getCurrentDateTime(String Dateformat) { String datestr = null; SimpleDateFormat df = new SimpleDateFormat(Dateformat); datestr = df.format(new Date()); return datestr; } public static String dateToDateTime(Date date) { String datestr = null; SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_TIME_FORMAT); datestr = df.format(date); return datestr; } /** * 将字符串日期转换为日期格式 * * * @param datestr * @return * */ public static Date stringToDate(String datestr) { if(datestr ==null ||datestr.equals("")){ return null; } Date date = new Date(); SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_FORMAT); try { date = df.parse(datestr); } catch (ParseException e) { date=DateUtils.stringToDate(datestr,"yyyyMMdd"); } return date; } /** * 将字符串日期转换为日期格式 * 自定義格式 * * @param datestr * @return * */ public static Date stringToDate(String datestr, String dateformat) { Date date = new Date(); SimpleDateFormat df = new SimpleDateFormat(dateformat); try { date = df.parse(datestr); } catch (ParseException e) { e.printStackTrace(); } return date; } /** * 将日期格式日期转换为字符串格式 * * * @param date * @return * */ public static String dateToString(Date date) { String datestr = null; SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_FORMAT); datestr = df.format(date); return datestr; } /** * 将日期格式日期转换为字符串格式 自定義格式 * * @param date * @param dateformat * @return */ public static String dateToString(Date date, String dateformat) { String datestr = null; SimpleDateFormat df = new SimpleDateFormat(dateformat); datestr = df.format(date); return datestr; } /** * 获取日期的DAY值 * * * @param date * 输入日期 * @return * */ public static int getDayOfDate(Date date) { int d = 0; Calendar cd = Calendar.getInstance(); cd.setTime(date); d = cd.get(Calendar.DAY_OF_MONTH); return d; } /** * 获取日期的MONTH值 * * * @param date * 输入日期 * @return * */ public static int getMonthOfDate(Date date) { int m = 0; Calendar cd = Calendar.getInstance(); cd.setTime(date); m = cd.get(Calendar.MONTH) + 1; return m; } /** * 获取日期的YEAR值 * * * @param date * 输入日期 * @return * */ public static int getYearOfDate(Date date) { int y = 0; Calendar cd = Calendar.getInstance(); cd.setTime(date); y = cd.get(Calendar.YEAR); return y; } /** * 获取星期几 * * * @param date * 输入日期 * @return * */ public static int getWeekOfDate(Date date) { int wd = 0; Calendar cd = Calendar.getInstance(); cd.setTime(date); wd = cd.get(Calendar.DAY_OF_WEEK) - 1; return wd; } /** * 获取输入日期的当月第一天 * * * @param date * 输入日期 * @return * */ public static Date getFirstDayOfMonth(Date date) { Calendar cd = Calendar.getInstance(); cd.setTime(date); cd.set(Calendar.DAY_OF_MONTH, 1); return cd.getTime(); } /** * 获得输入日期的当月最后一天 * * @param date */ public static Date getLastDayOfMonth(Date date) { return DateUtils.addDay(DateUtils.getFirstDayOfMonth(DateUtils.addMonth(date, 1)), -1); } /** * 判断是否是闰年 * * * @param date * 输入日期 * @return 是true 否false * */ public static boolean isLeapYEAR(Date date) { Calendar cd = Calendar.getInstance(); cd.setTime(date); int year = cd.get(Calendar.YEAR); if (year % 4 == 0 && year % 100 != 0 | year % 400 == 0) { return true; } else { return false; } } /** * 根据整型数表示的年月日，生成日期类型格式 * * @param year * 年 * @param month * 月 * @param day * 日 * @return * */ public static Date getDateByYMD(int year, int month, int day) { Calendar cd = Calendar.getInstance(); cd.set(year, month-1, day); return cd.getTime(); } /** * 获取年周期对应日 * * @param date * 输入日期 * @param iyear * 年数 負數表示之前 * @return * */ public static Date getYearCycleOfDate(Date date, int iyear) { Calendar cd = Calendar.getInstance(); cd.setTime(date); cd.add(Calendar.YEAR, iyear); return cd.getTime(); } /** * 获取月周期对应日 * * @param date * 输入日期 * @param i * @return * */ public static Date getMonthCycleOfDate(Date date, int i) { Calendar cd = Calendar.getInstance(); cd.setTime(date); cd.add(Calendar.MONTH, i); return cd.getTime(); } /** * 计算 fromDate 到 toDate 相差多少年 * * @param fromDate * @param toDate * @return 年数 * */ public static int getYearByMinusDate(Date fromDate, Date toDate) { Calendar df=Calendar.getInstance(); df.setTime(fromDate); Calendar dt=Calendar.getInstance(); dt.setTime(toDate); return dt.get(Calendar.YEAR)-df.get(Calendar.YEAR); } /** * 计算 fromDate 到 toDate 相差多少个月 * * @param fromDate * @param toDate * @return 月数 * */ public static int getMonthByMinusDate(Date fromDate, Date toDate) { Calendar df=Calendar.getInstance(); df.setTime(fromDate); Calendar dt=Calendar.getInstance(); dt.setTime(toDate); return dt.get(Calendar.YEAR)*12+dt.get(Calendar.MONTH)- (df.get(Calendar.YEAR)*12+df.get(Calendar.MONTH)); } /** * 计算 fromDate 到 toDate 相差多少天 * * @param fromDate * @param toDate * @return 天数 * */ public static long getDayByMinusDate(Object fromDate, Object toDate) { Date f=DateUtils.chgObject(fromDate); Date t=DateUtils.chgObject(toDate); long fd=f.getTime(); long td=t.getTime(); return (td-fd)/(24L * 60L * 60L * 1000L); } /** * 计算年龄 * * @param birthday * 生日日期 * @param calcDate * 要计算的日期点 * @return * */ public static int calcAge(Date birthday, Date calcDate) { int cYear=DateUtils.getYearOfDate(calcDate); int cMonth=DateUtils.getMonthOfDate(calcDate); int cDay=DateUtils.getDayOfDate(calcDate); int bYear=DateUtils.getYearOfDate(birthday); int bMonth=DateUtils.getMonthOfDate(birthday); int bDay=DateUtils.getDayOfDate(birthday); if(cMonth>bMonth||(cMonth==bMonth&&cDay>bDay)){ return cYear-bYear; }else{ return cYear-1-bYear; } } /** * 从身份证中获取出生日期 * * @param idno * 身份证号码 * @return * */ public static String getBirthDayFromIDCard(String idno) { Calendar cd = Calendar.getInstance(); if (idno.length() == 15) { cd.set(Calendar.YEAR, Integer.valueOf("19" + idno.substring(6, 8)) .intValue()); cd.set(Calendar.MONTH, Integer.valueOf(idno.substring(8, 10)) .intValue() - 1); cd.set(Calendar.DAY_OF_MONTH, Integer.valueOf(idno.substring(10, 12)).intValue()); } else if (idno.length() == 18) { cd.set(Calendar.YEAR, Integer.valueOf(idno.substring(6, 10)) .intValue()); cd.set(Calendar.MONTH, Integer.valueOf(idno.substring(10, 12)) .intValue() - 1); cd.set(Calendar.DAY_OF_MONTH, Integer.valueOf(idno.substring(12, 14)).intValue()); } return DateUtils.dateToString(cd.getTime()); } /** * 在输入日期上增加（+）或减去（-）天数 * * @param date * 输入日期 * @param imonth * 要增加或减少的天数 */ public static Date addDay(Date date, int iday) { Calendar cd = Calendar.getInstance(); cd.setTime(date); cd.add(Calendar.DAY_OF_MONTH, iday); return cd.getTime(); } /** * 在输入日期上增加（+）或减去（-）月份 * * @param date * 输入日期 * @param imonth * 要增加或减少的月分数 */ public static Date addMonth(Date date, int imonth) { Calendar cd = Calendar.getInstance(); cd.setTime(date); cd.add(Calendar.MONTH, imonth); return cd.getTime(); } /** * 在输入日期上增加（+）或减去（-）年份 * * @param date * 输入日期 * @param imonth * 要增加或减少的年数 */ public static Date addYear(Date date, int iyear) { Calendar cd = Calendar.getInstance(); cd.setTime(date); cd.add(Calendar.YEAR, iyear); return cd.getTime(); } /** * 將OBJECT類型轉換為Date * @param date * @return */ public static Date chgObject(Object date){ if(date!=null&&date instanceof Date){ return (Date)date; } if(date!=null&&date instanceof String){ return DateUtils.stringToDate((String)date); } return null; } public static long getAgeByBirthday(String date){ Date birthday = stringToDate(date, "yyyy-MM-dd"); long sec = new Date().getTime() - birthday.getTime(); long age = sec/(1000*60*60*24)/365; return age; } /** * @param args */ public static void main(String[] args) { //String temp = DateUtil.dateToString(getLastDayOfMonth(new Date()), /// DateUtil.DATE_FORMAT_CHINESE); //String s=DateUtil.dateToString(DateUtil.addDay(DateUtil.addYear(new Date(),1),-1)); long s=DateUtils.getDayByMinusDate("2012-01-01", "2012-12-31"); System.err.println(s); }}

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