给个Date,如何知道和当前的日期是不是在同一周?

Question

you can simply compare both YEAR and WEEK_OF_YEAR....

Answer 1

Calendar cal = Calendar.getInstance();
Calendar calNow = Calendar.getInstance();
cal.setTime(dateInst);
int subYear = calNow.get(Calendar.YEAR) - cal.get(Calendar.YEAR);
if (0 == subYear) {  if (0 = (cal.get(calNow.get(Calendar.WEEK_OF_YEAR) - cal.get(cal.get(Calendar.WEEK_OF_YEAR))) 
     return true;
}
else if (1 == subYear && (1 == calNow.get(Calendar.WEEK_OF_YEAR) && cal.get(Calendar.WEEK_OF_YEAR) == cal.getMaximum(Calendar.WEEK_OF_YEAR))) {
  if (1 != calNow.getFirstDayOfWeek())
    return true;
}
else if (-1 == subYear && (1 == cal.get(Calendar.WEEK_OF_YEAR) && calNow.get(Calendar.WEEK_OF_YEAR) == calNow.getMaximum(Calendar.WEEK_OF_YEAR))) {
  if (1 != cal.getFirstDayOfWeek())
    return true;
}
return false;//注意时区问题,美国以SUNDAY作为1周的第一天,而中国是MONDAY

Answer 2

上面回答有误,不好意思,下面是修改过的正确代码,经过测试了:boolean isSameWeekDates(Date date1, Date date2) {
Calendar cal1 = Calendar.getInstance();
Calendar cal2 = Calendar.getInstance();
cal1.setTime(date1);
cal2.setTime(date2);
int subYear = cal1.get(Calendar.YEAR) - cal2.get(Calendar.YEAR);
if (0 == subYear) {
  if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2.get(Calendar.WEEK_OF_YEAR))
return true;
}
else if (1 == subYear && 11 == cal2.get(Calendar.MONTH)) {
  // 如果12月的最后一周横跨来年第一周的话则最后一周即算做来年的第一周
  if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2.get(Calendar.WEEK_OF_YEAR))
return true;
}
else if (-1 == subYear && 11 == cal1.get(Calendar.MONTH)) {
  if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2.get(Calendar.WEEK_OF_YEAR))
return true;
}
return false;
}
//注意时区问题,美国以SUNDAY作为1周的第一天,而中国是MONDAY