如何获取当年的总周数？

我在 stackoverflow 上得到了下面的代码，它返回当年的总周数，但它是硬编码的，在 2014 年和 2016 年不起作用。我如何动态获取当年的总周数？？？

Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, 2015);
cal.set(Calendar.MONTH, Calendar.DECEMBER);
cal.set(Calendar.DAY_OF_MONTH, 31);

int ordinalDay = cal.get(Calendar.DAY_OF_YEAR);
int weekDay = cal.get(Calendar.DAY_OF_WEEK) - 1; // Sunday = 0
int numberOfWeeks = (ordinalDay - weekDay + 10) / 7;
System.out.println(numberOfWeeks);

我确实喜欢这个，只是检查它是当前方法吗？

     Calendar cal = Calendar.getInstance();
     int year = cal.get(Calendar.YEAR);
     cal.set(Calendar.YEAR, year);
     cal.set(Calendar.MONTH, Calendar.DECEMBER);
     cal.set(Calendar.DAY_OF_MONTH, 31);

     int ordinalDay = cal.get(Calendar.DAY_OF_YEAR);
     int weekDay = cal.get(Calendar.DAY_OF_WEEK) - 1; // Sunday = 0
     int numberOfWeeks = (ordinalDay - weekDay + 10) / 7;
     System.out.println(numberOfWeeks);

使用下面的代码

Calendar mCalendar = new GregorianCalendar(); 
mCalendar.set(Calendar.YEAR, 2014); // Set only year 
mCalendar.set(Calendar.MONTH, Calendar.DECEMBER); // Don't change
mCalendar.set(Calendar.DAY_OF_MONTH, 31); // Don't change
int totalWeeks = mCalendar.get(Calendar.WEEK_OF_YEAR);

不用关心每月的 30、28 和 29 天。一年（任何年份）的最后一天始终是 12 月 31 日。因此您需要设置这一天。和mCalendar.get(Calendar.WEEK_OF_YEAR)将返回当年的总周数。

更新动态方式

private int getTotalWeeksInYear(int year) {
        Calendar mCalendar = new GregorianCalendar(); 
        mCalendar.set(Calendar.YEAR, year); // Set only year 
        mCalendar.set(Calendar.MONTH, Calendar.DECEMBER); // Don't change
        mCalendar.set(Calendar.DAY_OF_MONTH, 31); // Don't change
        return mCalendar.get(Calendar.WEEK_OF_YEAR);
    }

    // Call as
    int totalWeeks = getTotalWeeksInYear(2014);

寻找上面代码中的错误。到时候您可以使用运行良好的以下代码

private int getTotalWeeksInYear(int year) {
        Calendar mCalendar = new GregorianCalendar(TimeZone.getDefault()); 
        mCalendar.setFirstDayOfWeek(Calendar.MONDAY);
        // Workaround
        mCalendar.set(year, 
                Calendar.DECEMBER, 
                31);
        int totalDaysInYear = mCalendar.get(Calendar.DAY_OF_YEAR);
        System.out.println(totalDaysInYear);
        int totalWeeks = totalDaysInYear / 7; 
        return totalWeeks;
    }