java中 獲取天，周，月，年的開始時間和結束時間

下方代碼直接 懟上。。。。。。。。

package demoone;   import java.sql.Timestamp; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Calendar; import java.util.Date; import java.util.GregorianCalendar; import java.util.List;   public class DateUtils {     //獲取當天的開始時間     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();     }     //獲取當天的結束時間     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();     }     //獲取昨天的開始時間     public static Date getBeginDayOfYesterday() {         Calendar cal = new GregorianCalendar();         cal.setTime(getDayBegin());         cal.add(Calendar.DAY_OF_MONTH, -1);         return cal.getTime();     }     //獲取昨天的結束時間     public static Date getEndDayOfYesterDay() {         Calendar cal = new GregorianCalendar();         cal.setTime(getDayEnd());         cal.add(Calendar.DAY_OF_MONTH, -1);         return cal.getTime();     }     //獲取明天的開始時間     public static Date getBeginDayOfTomorrow() {         Calendar cal = new GregorianCalendar();         cal.setTime(getDayBegin());         cal.add(Calendar.DAY_OF_MONTH, 1);           return cal.getTime();     }     //獲取明天的結束時間     public static Date getEndDayOfTomorrow() {         Calendar cal = new GregorianCalendar();         cal.setTime(getDayEnd());         cal.add(Calendar.DAY_OF_MONTH, 1);         return cal.getTime();     }     //獲取本週的開始時間     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());     }     //獲取本週的結束時間     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);     }     //獲取本月的開始時間      public static Date getBeginDayOfMonth() {             Calendar calendar = Calendar.getInstance();             calendar.set(getNowYear(), getNowMonth() - 1, 1);             return getDayStartTime(calendar.getTime());         }     //獲取本月的結束時間      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());         }      //獲取本年的開始時間      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());         }      //獲取本年的結束時間      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());         }     //獲取某個日期的開始時間     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());     }     //獲取某個日期的結束時間     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());     }     //獲取今年是哪一年      public static Integer getNowYear() {              Date date = new Date();             GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();             gc.setTime(date);             return Integer.valueOf(gc.get(1));         }      //獲取本月是哪一月      public static int getNowMonth() {              Date date = new Date();             GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();             gc.setTime(date);             return gc.get(2) + 1;         }      //兩個日期相減獲得的天數      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;         }     //兩個日期相減獲得的毫秒數      public static long dateDiff(Date beginDate, Date endDate) {             long date1ms = beginDate.getTime();             long date2ms = endDate.getTime();             return date2ms - date1ms;         }      //獲取兩個日期中的最大日期      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;         }      //獲取兩個日期中的最小日期      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;         }      //返回某月該季度的第一個月      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();         }      //返回某個日期下幾天的日期      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();         }      //返回某個日期前幾天的日期      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();         }      //獲取某年某月到某年某月按天的切片日期集合（間隔天數的日期集合）      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;         }      //獲取某年某月按天切片日期集合（某個月間隔多少天的日期集合）      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;         } } //獲取某年某月的第一天日期  public static Date getStartMonthDate(int year, int month) {         Calendar calendar = Calendar.getInstance();         calendar.set(year, month - 1, 1);         return calendar.getTime();     }   //獲取某年某月的最後一天日期    public static Date getEndMonthDate(int year, int month) {         Calendar calendar = Calendar.getInstance();         calendar.set(year, month - 1, 1);         int day = calendar.getActualMaximum(5);         calendar.set(year, month - 1, day);         return calendar.getTime();     }