Java写的获取日期工具类（今天、昨天、本周、上周、本月、上月、本年及特定时间的开始时间和结束时间）

由于获取日期经常会使用到，所有我自己写了一个工具类

1、基本上能用上的都写出来了，包括：

1）获取当天的开始时间
2）获取当天的结束时间
3）获取昨天的开始时间
4）获取昨天的结束时间
5）获取明天的开始时间
6）获取明天的结束时间
7）获取本周的开始时间
8）获取本周的结束时间
9）获取上周的开始时间
10）获取上周的结束时间
11）获取本月的开始时间
12）获取本月的结束时间
13）获取上月的开始时间
14）获取上月的结束时间
15）获取本年的开始时间
16）获取本年的结束时间
17）获取某个日期的开始时间
18）获取某个日期的结束时间
19）获取今年是哪一年
20）获取本月是哪一月
21）两个日期相减得到的天数
22）两个日期相减得到的毫秒数
23）获取两个日期中的最大日期
24）获取两个日期中的最小日期
25）返回某月该季度的第一个月
26）返回某个日期下几天的日期
27）返回某个日期前几天的日期
28）获取某年某月到某年某月按天的切片日期集合（间隔天数的集合）
29）获取某年某月按天切片日期集合（某个月间隔多少天的日期集合）

2、直接上源码：

import java.sql.Timestamp;import java.util.ArrayList; import java.util.Calendar; import java.util.Date; import java.util.GregorianCalendar; import java.util.List; public class DateUtils {     //获取当天的开始时间     public static java.util.Date getDayBegin() {         Calendar cal = new GregorianCalendar();         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();     }     //获取当天的结束时间     public static java.util.Date getDayEnd() {         Calendar cal = new GregorianCalendar();         cal.set(Calendar.HOUR_OF_DAY, 23);         cal.set(Calendar.MINUTE, 59);         cal.set(Calendar.SECOND, 59);         return cal.getTime();     }     //获取昨天的开始时间     public static Date getBeginDayOfYesterday() {         Calendar cal = new GregorianCalendar();         cal.setTime(getDayBegin());         cal.add(Calendar.DAY_OF_MONTH, -1);         return cal.getTime();     }     //获取昨天的结束时间     public static Date getEndDayOfYesterDay() {         Calendar cal = new GregorianCalendar();         cal.setTime(getDayEnd());         cal.add(Calendar.DAY_OF_MONTH, -1);         return cal.getTime();     }     //获取明天的开始时间     public static Date getBeginDayOfTomorrow() {         Calendar cal = new GregorianCalendar();         cal.setTime(getDayBegin());         cal.add(Calendar.DAY_OF_MONTH, 1);         return cal.getTime();     }     //获取明天的结束时间     public static Date getEndDayOfTomorrow() {         Calendar cal = new GregorianCalendar();         cal.setTime(getDayEnd());         cal.add(Calendar.DAY_OF_MONTH, 1);         return cal.getTime();     }     //获取本周的开始时间     @SuppressWarnings("unused")    public static Date getBeginDayOfWeek() {         Date date = new Date();         if (date == null) {             return null;         }         Calendar cal = Calendar.getInstance();         cal.setTime(date);         int dayofweek = cal.get(Calendar.DAY_OF_WEEK);         if (dayofweek == 1) {             dayofweek += 7;         }         cal.add(Calendar.DATE, 2 - dayofweek);         return getDayStartTime(cal.getTime());     }     //获取本周的结束时间     public static Date getEndDayOfWeek(){         Calendar cal = Calendar.getInstance();         cal.setTime(getBeginDayOfWeek());         cal.add(Calendar.DAY_OF_WEEK, 6);         Date weekEndSta = cal.getTime();         return getDayEndTime(weekEndSta);     }     //获取上周的开始时间     @SuppressWarnings("unused")     public static Date getBeginDayOfLastWeek() {         Date date = new Date();         if (date == null) {             return null;         }         Calendar cal = Calendar.getInstance();         cal.setTime(date);         int dayofweek = cal.get(Calendar.DAY_OF_WEEK);         if (dayofweek == 1) {             dayofweek += 7;         }         cal.add(Calendar.DATE, 2 - dayofweek - 7);         return getDayStartTime(cal.getTime());     }     //获取上周的结束时间     public static Date getEndDayOfLastWeek(){         Calendar cal = Calendar.getInstance();         cal.setTime(getBeginDayOfLastWeek());         cal.add(Calendar.DAY_OF_WEEK, 6);         Date weekEndSta = cal.getTime();         return getDayEndTime(weekEndSta);     }     //获取本月的开始时间      public static Date getBeginDayOfMonth() {             Calendar calendar = Calendar.getInstance();             calendar.set(getNowYear(), getNowMonth() - 1, 1);             return getDayStartTime(calendar.getTime());         }     //获取本月的结束时间      public static Date getEndDayOfMonth() {             Calendar calendar = Calendar.getInstance();             calendar.set(getNowYear(), getNowMonth() - 1, 1);             int day = calendar.getActualMaximum(5);             calendar.set(getNowYear(), getNowMonth() - 1, day);             return getDayEndTime(calendar.getTime());         }      //获取上月的开始时间      public static Date getBeginDayOfLastMonth() {          Calendar calendar = Calendar.getInstance();          calendar.set(getNowYear(), getNowMonth() - 2, 1);          return getDayStartTime(calendar.getTime());      }      //获取上月的结束时间      public static Date getEndDayOfLastMonth() {          Calendar calendar = Calendar.getInstance();          calendar.set(getNowYear(), getNowMonth() - 2, 1);          int day = calendar.getActualMaximum(5);          calendar.set(getNowYear(), getNowMonth() - 2, day);          return getDayEndTime(calendar.getTime());      }      //获取本年的开始时间      public static java.util.Date getBeginDayOfYear() {             Calendar cal = Calendar.getInstance();             cal.set(Calendar.YEAR, getNowYear());             // cal.set             cal.set(Calendar.MONTH, Calendar.JANUARY);             cal.set(Calendar.DATE, 1);             return getDayStartTime(cal.getTime());         }      //获取本年的结束时间      public static java.util.Date getEndDayOfYear() {             Calendar cal = Calendar.getInstance();             cal.set(Calendar.YEAR, getNowYear());             cal.set(Calendar.MONTH, Calendar.DECEMBER);             cal.set(Calendar.DATE, 31);             return getDayEndTime(cal.getTime());         }     //获取某个日期的开始时间     public static Timestamp getDayStartTime(Date d) {         Calendar calendar = Calendar.getInstance();         if(null != d) calendar.setTime(d);         calendar.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH),    calendar.get(Calendar.DAY_OF_MONTH), 0, 0, 0);         calendar.set(Calendar.MILLISECOND, 0);         return new Timestamp(calendar.getTimeInMillis());     }     //获取某个日期的结束时间     public static Timestamp getDayEndTime(Date d) {         Calendar calendar = Calendar.getInstance();         if(null != d) calendar.setTime(d);         calendar.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH),    calendar.get(Calendar.DAY_OF_MONTH), 23, 59, 59);         calendar.set(Calendar.MILLISECOND, 999);         return new Timestamp(calendar.getTimeInMillis());     }     //获取今年是哪一年      public static Integer getNowYear() {              Date date = new Date();             GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();             gc.setTime(date);             return Integer.valueOf(gc.get(1));         }      //获取本月是哪一月      public static int getNowMonth() {              Date date = new Date();             GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();             gc.setTime(date);             return gc.get(2) + 1;         }      //两个日期相减得到的天数      public static int getDiffDays(Date beginDate, Date endDate) {             if (beginDate == null || endDate == null) {                 throw new IllegalArgumentException("getDiffDays param is null!");             }             long diff = (endDate.getTime() - beginDate.getTime())                     / (1000 * 60 * 60 * 24);             int days = new Long(diff).intValue();             return days;         }     //两个日期相减得到的毫秒数      public static long dateDiff(Date beginDate, Date endDate) {             long date1ms = beginDate.getTime();             long date2ms = endDate.getTime();             return date2ms - date1ms;         }      //获取两个日期中的最大日期      public static Date max(Date beginDate, Date endDate) {             if (beginDate == null) {                 return endDate;             }             if (endDate == null) {                 return beginDate;             }             if (beginDate.after(endDate)) {                 return beginDate;             }             return endDate;         }      //获取两个日期中的最小日期      public static Date min(Date beginDate, Date endDate) {             if (beginDate == null) {                 return endDate;             }             if (endDate == null) {                 return beginDate;             }             if (beginDate.after(endDate)) {                 return endDate;             }             return beginDate;         }      //返回某月该季度的第一个月      public static Date getFirstSeasonDate(Date date) {              final int[] SEASON = { 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4 };             Calendar cal = Calendar.getInstance();             cal.setTime(date);             int sean = SEASON[cal.get(Calendar.MONTH)];             cal.set(Calendar.MONTH, sean * 3 - 3);             return cal.getTime();         }      //返回某个日期下几天的日期      public static Date getNextDay(Date date, int i) {             Calendar cal = new GregorianCalendar();             cal.setTime(date);             cal.set(Calendar.DATE, cal.get(Calendar.DATE) + i);             return cal.getTime();         }      //返回某个日期前几天的日期      public static Date getFrontDay(Date date, int i) {             Calendar cal = new GregorianCalendar();             cal.setTime(date);             cal.set(Calendar.DATE, cal.get(Calendar.DATE) - i);             return cal.getTime();         }      //获取某年某月到某年某月按天的切片日期集合（间隔天数的集合）      @SuppressWarnings({ "rawtypes", "unchecked" })    public static List getTimeList(int beginYear, int beginMonth, int endYear,                 int endMonth, int k) {             List list = new ArrayList();             if (beginYear == endYear) {                 for (int j = beginMonth; j <= endMonth; j++) {                     list.add(getTimeList(beginYear, j, k));                 }             } else {                 {                     for (int j = beginMonth; j < 12; j++) {                         list.add(getTimeList(beginYear, j, k));                     }                     for (int i = beginYear + 1; i < endYear; i++) {                         for (int j = 0; j < 12; j++) {                             list.add(getTimeList(i, j, k));                         }                     }                     for (int j = 0; j <= endMonth; j++) {                         list.add(getTimeList(endYear, j, k));                     }                 }             }             return list;         }      //获取某年某月按天切片日期集合（某个月间隔多少天的日期集合）      @SuppressWarnings({ "unchecked", "rawtypes" })    public static List getTimeList(int beginYear, int beginMonth, int k) {             List list = new ArrayList();             Calendar begincal = new GregorianCalendar(beginYear, beginMonth, 1);             int max = begincal.getActualMaximum(Calendar.DATE);             for (int i = 1; i < max; i = i + k) {                 list.add(begincal.getTime());                 begincal.add(Calendar.DATE, k);             }             begincal = new GregorianCalendar(beginYear, beginMonth, max);             list.add(begincal.getTime());             return list;         }}

3、小提示

由于为了以后使用方便，所有方法的返回类型都设为了 java.util.Date
请在使用时根据自己的需要进行日期格式化处理，如：

import java.text.SimpleDateFormat;SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");String todayBegin = simpleDateFormat.format(DateUtils.getDayBegin());System.out.println(todayBegin );//输出结果为2017-10-26 00:00:00