DateUtil工具类

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我是靠谱客的博主勤恳楼房，最近开发中收集的这篇文章主要介绍DateUtil工具类，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

  //定义常用变量-
public static final String DATE_FORMAT_FULL = "yyyy-MM-dd HH:mm:ss";
public static final String DATE_FORMAT_YMD = "yyyy-MM-dd";
public static final String DATE_FORMAT_HMS = "HH:mm:ss";
public static final String DATE_FORMAT_HM = "HH:mm";
public static final String DATE_FORMAT_YMDHM = "yyyy-MM-dd HH:mm";
public static final String DATE_FORMAT_YMDHMS = "yyyyMMddHHmmss";
public static final long ONE_DAY_MILLS = 3600000 * 24;
public static final int WEEK_DAYS = 7;
private static final int DATE_LENGHT = DATE_FORMAT_YMDHM.length();

1.日期转换为制定格式字符串
public static String formatDateToString(Date time, String format) {
if (time == null) {
return null;
}
SimpleDateFormat sdf = new SimpleDateFormat(format);
return sdf.format(time);
}

2.字符串转换成制定格式日期
public static Date formatStringToDate(String date, String format) {
SimpleDateFormat sdf = new SimpleDateFormat(format);
try {
return sdf.parse(date);
} catch (ParseException ex) {
log.error(ex.getMessage());
return null;
}
}

3.判断一个日期是否属于两个时段内
public static boolean isTimeInRange(Date time, Date[] timeRange) {
return (!time.before(timeRange[0]) && !time.after(timeRange[1]));
}

4.从完整的时间截取精确到分的时间
public static String getDateToMinute(String fullDateStr) {
return fullDateStr == null ? null
: (fullDateStr.length() >= DATE_LENGHT ? fullDateStr.substring(0, DATE_LENGHT) : fullDateStr);
}

5.返回指定年度的所有周。List中包含的是String[2]对象 string[0]本周的开始日期,string[1]是本周的结束日期。日期的格式为YYYY-MM-DD 每年的第一个周，必须包含星期一且是完整的七天。例如：2009年的第一个周开始日期为2009-01-05，结束日期为2009-01-11。星期一在哪一年，那么包含这个星期的周就是哪一年的周。例如：2008-12-29是星期一，2009-01-04是星期日，哪么这个周就是2008年度的最后一个周
public static List<String[]> getWeeksByYear(final int year) {
int weeks = getWeekNumOfYear(year);
List<String[]> result = new ArrayList<>(weeks);
int start = 1;
int end = 7;
for (int i = 1; i <= weeks; i++) {
String[] tempWeek = new String[2];
tempWeek[0] = getDateForDayOfWeek(year, i, start);
tempWeek[1] = getDateForDayOfWeek(year, i, end);
result.add(tempWeek);
}
return result;
}

6.计算制定年、周的上一年、周
public static int[] getLastYearWeek(int year, int week) {
if (week <= 0) {
throw new IllegalArgumentException(“周序号不能小于1！！”);
}
int[] result = { week, year };
if (week == 1) {
// 上一年
result[1] -= 1;
// 最后一周
result[0] = getWeekNumOfYear(result[1]);
} else {
result[0] -= 1;
}
return result;
}

7.下一个[年、周]
public static int[] getNextYearWeek(int year, int week) {
if (week <= 0) {
throw new IllegalArgumentException(“周序号不能小于1！！”);
}
int[] result = { week, year };
int weeks = getWeekNumOfYear(year);
if (week == weeks) {
// 下一年
result[1] += 1;
// 第一周
result[0] = 1;
} else {
result[0] += 1;
}
return result;
}

8.计算指定年度共有多少个周（从周一开始）
public static int getWeekNumOfYear(final int year) {
return getWeekNumOfYear(year, Calendar.MONDAY);
}
public static int getWeekNumOfYear(final int year, int firstDayOfWeek) {
// 每年至少有52个周，最多有53个周。
int minWeeks = 52;
int maxWeeks = 53;
int result = minWeeks;
int sIndex = 4;
String date = getDateForDayOfWeek(year, maxWeeks, firstDayOfWeek);
// 判断年度是否相符，如果相符说明有53个周。
if (date.substring(0, sIndex).equals(String.valueOf(year))) {
result = maxWeeks;
}
return result;
}
public static int getWeeksOfWeekYear(final int year) {
Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.setMinimalDaysInFirstWeek(WEEK_DAYS);
cal.set(Calendar.YEAR, year);
return cal.getWeeksInWeekYear();
}

9.获取指定年份的第几周的第几天对应的日期yyyy-MM-dd，指定周几算一周的第一天（firstDayOfWeek）
public static String getDateForDayOfWeek(int year, int weekOfYear, int dayOfWeek, int firstDayOfWeek) {
Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(firstDayOfWeek);
cal.set(Calendar.DAY_OF_WEEK, dayOfWeek);
cal.setMinimalDaysInFirstWeek(WEEK_DAYS);
cal.set(Calendar.YEAR, year);
cal.set(Calendar.WEEK_OF_YEAR, weekOfYear);
return formatDateToString(cal.getTime(), DATE_FORMAT_YMD);
}

10.获取指定日期的星期几
public static int getWeekOfDate(String datetime) {
Calendar cal = Calendar.getInstance();
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.setMinimalDaysInFirstWeek(WEEK_DAYS);
Date date = formatStringToDate(datetime, DATE_FORMAT_YMD);
cal.setTime(date);
return cal.get(Calendar.DAY_OF_WEEK);

11.计算某年周内的所有日期(从周一开始为每周的第一天)
public static List getWeekDays(int yearNum, int weekNum) {
return getWeekDays(yearNum, weekNum, Calendar.MONDAY);
}
计算某年某周内的所有日期(七天)
public static List getWeekDays(int year, int weekOfYear, int firstDayOfWeek) {
List dates = new ArrayList<>();
int dayOfWeek = firstDayOfWeek;
for (int i = 0; i < WEEK_DAYS; i++) {
dates.add(getDateForDayOfWeek(year, weekOfYear, dayOfWeek++, firstDayOfWeek));
}
return dates;
}

12.获取目标日期的上周、或本周、或下周的年、周信息
queryDate 传入的时间
weekOffset -1:上周 0:本周 1:下周
firstDayOfWeek 每周以第几天为首日
public static int[] getWeekAndYear(String queryDate, int weekOffset, int firstDayOfWeek) {

	Date date = formatStringToDate(queryDate, DATE_FORMAT_YMD);
	Calendar calendar = Calendar.getInstance();
	calendar.setTime(date);
	calendar.setFirstDayOfWeek(firstDayOfWeek);
	calendar.setMinimalDaysInFirstWeek(WEEK_DAYS);
	int year = calendar.getWeekYear();
	int week = calendar.get(Calendar.WEEK_OF_YEAR);
	int[] result = { week, year };
	switch (weekOffset) {
	case 1:
		result = getNextYearWeek(year, week);
		break;
	case -1:
		result = getLastYearWeek(year, week);
		break;
	default:
		break;
	}
	return result;
}

13.计算两个日期的天数（startDate 开始日期字串、endDate 结束日期字串）
public static int getDaysBetween(String startDate, String endDate) {
int dayGap = 0;
if (startDate != null && startDate.length() > 0 && endDate != null && endDate.length() > 0) {
Date end = formatStringToDate(endDate, DATE_FORMAT_YMD);
Date start = formatStringToDate(startDate, DATE_FORMAT_YMD);
dayGap = getDaysBetween(start, end);
}
return dayGap;
}

private static int getDaysBetween(Date startDate, Date endDate) {
	return (int) ((endDate.getTime() - startDate.getTime()) / ONE_DAY_MILLS);
}

14 计算两个日期之间的天数差
public static int getDaysGapOfDates(Date startDate, Date endDate) {
int date = 0;
if (startDate != null && endDate != null) {
date = getDaysBetween(startDate, endDate);
}
return date;
}
15计算两个日期之间的年份差距
public static int getYearGapOfDates(Date firstDate, Date secondDate) {
if (firstDate == null || secondDate == null) {
return 0;
}
Calendar helpCalendar = Calendar.getInstance();
helpCalendar.setTime(firstDate);
int firstYear = helpCalendar.get(Calendar.YEAR);
helpCalendar.setTime(secondDate);
int secondYear = helpCalendar.get(Calendar.YEAR);
return secondYear - firstYear;
}

16计算两个日期之间的月份差距
public static int getMonthGapOfDates(Date firstDate, Date secondDate) {
if (firstDate == null || secondDate == null) {
return 0;
}

	return (int) ((secondDate.getTime() - firstDate.getTime()) / ONE_DAY_MILLS / 30);

}

17计算是否包含当前日期
public static boolean isContainCurrent(List dates) {
boolean flag = false;
SimpleDateFormat fmt = new SimpleDateFormat(DATE_FORMAT_YMD);
Date date = new Date();
String dateStr = fmt.format(date);
for (int i = 0; i < dates.size(); i++) {
if (dateStr.equals(dates.get(i))) {
flag = true;
}
}
return flag;
}
18从date开始计算time天后的日期
public static String getCalculateDateToString(String startDate, int time) {
String resultDate = null;
if (startDate != null && startDate.length() > 0) {
Date date = formatStringToDate(startDate, DATE_FORMAT_YMD);
Calendar c = Calendar.getInstance();
c.setTime(date);
c.set(Calendar.DAY_OF_YEAR, time);
date = c.getTime();
resultDate = formatDateToString(date, DATE_FORMAT_YMD);
}
return resultDate;
}

19获取从某日期开始计算，指定的日期所在该年的第几周 public static int[] getYearAndWeeks(String date, String admitDate) {
Calendar c = Calendar.getInstance();
c.setTime(formatStringToDate(admitDate, DATE_FORMAT_YMD));
int time = c.get(Calendar.DAY_OF_WEEK);
return getWeekAndYear(date, 0, time);
}

20.获取指定日期refDate，前或后一周的所有日期
public static List getWeekDaysAroundDate(String refDate, int weekOffset, String startDate) {
// 以startDate为一周的第一天
Calendar c = Calendar.getInstance();
c.setTime(formatStringToDate(startDate, DATE_FORMAT_YMD));
int firstDayOfWeek = c.get(Calendar.DAY_OF_WEEK);
// 获取相应周
int[] weekAndYear = getWeekAndYear(refDate, weekOffset, firstDayOfWeek);
// 获取相应周的所有日期
return getWeekDays(weekAndYear[1], weekAndYear[0], firstDayOfWeek);
}

21根据时间点获取时间区间
public static List<String[]> getTimePointsByHour(int[] hours) {
List<String[]> hourPoints = new ArrayList<>();
String sbStart = “:00:00”;
String sbEnd = “:59:59”;
for (int i = 0; i < hours.length; i++) {
String[] times = new String[2];
times[0] = hours[i] + sbStart;
times[1] = (hours[(i + 1 + hours.length) % hours.length] - 1) + sbEnd;
hourPoints.add(times);
}
return hourPoints;
}

22根据指定的日期，增加或者减少天数
public static Date addDays(Date date, int amount) {
return add(date, Calendar.DAY_OF_MONTH, amount);
}
public static Date add(Date date, int calendarField, int amount) {
if (date == null) {
throw new IllegalArgumentException(“The date must not be null”);
}
Calendar c = Calendar.getInstance();
c.setTime(date);
c.add(calendarField, amount);
return c.getTime();
}
23获取当前日期的最大日期时间2014-12-21 23:59:59
public static Date getCurDateWithMaxTime() {
Calendar c = Calendar.getInstance();
c.set(Calendar.HOUR_OF_DAY, 23);
c.set(Calendar.MINUTE, 59);
c.set(Calendar.SECOND, 59);
return c.getTime();
}

24.获取当前日期的最小日期时间 2014-12-21 00:00:00
public static Date getCurDateWithMinTime() {
Calendar c = Calendar.getInstance();
c.set(Calendar.HOUR_OF_DAY, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
return c.getTime();
}