import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
/** *//**
*
* @author zzk
*
*/
public class DateUtil {
/** *//**
* 取得某天相加(减)後的那一天
*
* @param date
* @param num(可正可负)
* @return
*/
public static Date getAnotherDate(Date date, int num) {
Calendar c = Calendar.getInstance();
c.setTime(date);
c.add(Calendar.DAY_OF_YEAR, num);
return c.getTime();
}
/** *//**
* 取得某月的的最后一天
*
* @param year
* @param month
* @return
*/
public static Date getLastDayOfMonth(int year, int month) {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, year);// 年
cal.set(Calendar.MONTH, month - 1);// 月,因为Calendar里的月是从0开始,所以要减1
//设置该月实际的最后一天
cal.set(Calendar.DATE,cal.getActualMaximum(Calendar.DATE));
return cal.getTime();// 获得月末是几号
}
/** *//**
* 取得某天是一年中的多少周
*
* @param date
* @return
*/
public static int getWeekOfYear(Date date) {
Calendar c = new GregorianCalendar();
c.setFirstDayOfWeek(Calendar.MONDAY);
c.setMinimalDaysInFirstWeek(7);
c.setTime(date);
return c.get(Calendar.WEEK_OF_YEAR);
}
/** *//**
* 取得某天所在周的第一天
*
* @param date
* @return
*/
public static Date getFirstDayOfWeek(Date date) {
Calendar c = new GregorianCalendar();
c.setFirstDayOfWeek(Calendar.MONDAY);
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
return c.getTime();
}
/** *//**
* 取得某天所在周的最后一天
*
* @param date
* @return
*/
public static Date getLastDayOfWeek(Date date) {
Calendar c = new GregorianCalendar();
c.setFirstDayOfWeek(Calendar.MONDAY);
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek() + 6);
return c.getTime();
}
/** *//**
* 取得某一年共有多少周
*
* @param year
* @return
*/
public static int getMaxWeekNumOfYear(int year) {
Calendar c = new GregorianCalendar();
c.set(year, Calendar.DECEMBER, 31, 23, 59, 59);
return getWeekOfYear(c.getTime());
}
/** *//**
* 取得某年某周的第一天
* 对于交叉:2008-12-29到2009-01-04属于2008年的最后一周,2009-01-05为2009年第一周的第一天
* @param year
* @param week
* @return
*/
public static Date getFirstDayOfWeek(int year, int week) {
Calendar calFirst = Calendar.getInstance();
calFirst.set(year, 0, 7);
Date firstDate = getFirstDayOfWeek(calFirst.getTime());
Calendar firstDateCal = Calendar.getInstance();
firstDateCal.setTime(firstDate);
Calendar c = new GregorianCalendar();
c.set(Calendar.YEAR, year);
c.set(Calendar.MONTH, Calendar.JANUARY);
c.set(Calendar.DATE, firstDateCal.get(Calendar.DATE));
Calendar cal = (GregorianCalendar) c.clone();
cal.add(Calendar.DATE, (week - 1) * 7);
firstDate = getFirstDayOfWeek(cal.getTime());
return firstDate;
}
/** *//**
* 取得某年某周的最后一天
* 对于交叉:2008-12-29到2009-01-04属于2008年的最后一周,2009-01-04为2008年最后一周的最后一天
* @param year
* @param week
* @return
*/
public static Date getLastDayOfWeek(int year, int week) {
Calendar calLast = Calendar.getInstance();
calLast.set(year, 0, 7);
Date firstDate = getLastDayOfWeek(calLast.getTime());
Calendar firstDateCal = Calendar.getInstance();
firstDateCal.setTime(firstDate);
Calendar c = new GregorianCalendar();
c.set(Calendar.YEAR, year);
c.set(Calendar.MONTH, Calendar.JANUARY);
c.set(Calendar.DATE, firstDateCal.get(Calendar.DATE));
Calendar cal = (GregorianCalendar) c.clone();
cal.add(Calendar.DATE, (week - 1) * 7);
Date lastDate = getLastDayOfWeek(cal.getTime());
return lastDate;
}
}
Java中对日期的常用处理(转)
最新推荐文章于 2024-10-16 09:46:18 发布