试试

calendar.setFirstDayOfWeek(Calendar.MONDAY); //sets first day to monday, for example.

在您的情况下，您可能想要这样做:

In your case you might want to do this:

public int getWeeksOfMonth(int year, int month, int weekStart) { 
    Calendar calendar = Calendar.getInstance();  
    calendar.set(Calendar.MONTH, month-1);
    calendar.set(Calendar.YEAR, year);
    calendar.setFirstDayOfWeek(weekStart);
    int numOfWeeksInMonth = calendar.getActualMaximum(Calendar.WEEK_OF_MONTH); 

    return numOfWeeksInMonth;
}

并用一行如

int weeks = getWeeksOfMonth(2012, 5, Calendar.WEDNESDAY);