java - 如何从给定的 WEEK_OF_YEAR、DAY_OF_WEEK、YEAR 获取 Calendar.MONTH

Question

知道年、年中的星期和星期中的日期，就可以获得年中的月份和月份中的日期。例如

 // corresponding to September 15, 2012 if week starts on Monday
 int weekNum = 38;
 int dayNum = 6;
 int year = 2012;

 // set the calendar instance the a week of year and day in the future
  Calendar aGMTCalendar = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
 aGMTCalendar.setFirstDayOfWeek(Calendar.MONDAY);    
 aGMTCalendar.set(Calendar.WEEK_OF_YEAR,weekNum ); 
 aGMTCalendar.set(Calendar.DAY_OF_WEEK,dayNum );
 aGMTCalendar.set(Calendar.YEAR,year);

// get the month and day of month
 int   monthGMT = aGMTCalendar.get(Calendar.MONTH + 1); // returns 38  not 9

 int   dayOfMonthNumGMT = aGMTCalendar.get(Calendar.DAY_OF_MONTH); 
 // returns 14 but I wanted 15

谢谢

Answer 1

应该是

// +1 to the value of month returned, not to the value of MONTH constant.
int monthGMT = aGMTCalendar.get(Calendar.MONTH) + 1;