timeUtil

/**
* 字符串的日期 格式 yyyy-MM-dd
* 转入参数，添加或减去它的天数，在返回字符串
*/
public static String addOrDelRq(String rq,int num) throws Exception {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar c = Calendar.getInstance();
c.setTime(sdf.parse(rq));
c.add(Calendar.DATE, num);
String rtn = sdf.format(c.getTime());
return rtn;
}

// 获取当前时间所在年的周数
public 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);
}

// 获取当前时间所在年的最大周数
public int getMaxWeekNumOfYear(int year) {
Calendar c = new GregorianCalendar();
c.set(year, Calendar.DECEMBER, 31, 23, 59, 59);

return getWeekOfYear(c.getTime());
}

// 获取某年的第几周的开始日期
public Date getFirstDayOfWeek(int year, int week) {
// week+=-1;
Calendar c = new GregorianCalendar();
c.set(Calendar.YEAR, year);
c.set(Calendar.MONTH, Calendar.JANUARY);
c.set(Calendar.DATE, 1);

Calendar cal = (GregorianCalendar) c.clone();
cal.add(Calendar.DATE, week * 7);
cal.add(Calendar.DATE, -1);
/* //如果第一周有上一年的时间
if(week==1){

}*/

return getFirstDayOfWeek(cal.getTime());
}

// 获取某年的第几周的结束日期
public Date getLastDayOfWeek(int year, int week) {
// week+=-1;
Calendar c = new GregorianCalendar();
c.set(Calendar.YEAR, year);
c.set(Calendar.MONTH, Calendar.JANUARY);
c.set(Calendar.DATE, 1);

Calendar cal = (GregorianCalendar) c.clone();
cal.add(Calendar.DATE, week * 7);
cal.add(Calendar.DATE, -1);

return getLastDayOfWeek(cal.getTime());
}

// 获取当前时间所在周的开始日期
public Date getFirstDayOfWeek(Date date) {
Calendar c = new GregorianCalendar();
c.setFirstDayOfWeek(Calendar.MONDAY);
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek()); // Monday
return c.getTime();
}

// 获取当前时间所在周的结束日期
public Date getLastDayOfWeek(Date date) {
Calendar c = new GregorianCalendar();
c.setFirstDayOfWeek(Calendar.MONDAY);
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek() + 6); // Sunday
return c.getTime();
}