Java Utililty Methods Day of Week

Calendar calendar = getCalendarFromDate(date);
calendar.setFirstDayOfWeek(Calendar.MONDAY);
return calendar.get(Calendar.WEEK_OF_YEAR) - 1;

Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.setFirstDayOfWeek(Calendar.SUNDAY);
cal.setMinimalDaysInFirstWeek(1);
return cal.get(Calendar.WEEK_OF_YEAR);
...

String[] tempYear = date.trim().split("-");
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, Integer.valueOf(tempYear[0]));
cal.set(Calendar.MONTH, (Integer.valueOf(tempYear[1]) - 1));
cal.set(Calendar.DATE, Integer.valueOf(tempYear[2]));
int week = cal.get(Calendar.WEEK_OF_YEAR);
return String.valueOf(week);

int bWeek = getDateField(begin, Calendar.WEEK_OF_YEAR);
int eWeek = getDateField(end, Calendar.WEEK_OF_YEAR);
return eWeek - bWeek;

if (date == null) {
    return null;
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
...

Calendar calendar = new GregorianCalendar();
calendar.setTime(date);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
return calendar.getTime();
...

Calendar calendar = Calendar.getInstance();
calendar.setTime(current);
calendar.setFirstDayOfWeek(Calendar.MONDAY);
calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
...

if (sDate == null || sDate.length() != 8)
    return -1;
Calendar c = Calendar.getInstance(Locale.KOREA);
c.set(Integer.parseInt(sDate.substring(0, 4)), Integer.parseInt(sDate.substring(4, 6)) - 1,
        Integer.parseInt(sDate.substring(6)));
GregorianCalendar gc = new GregorianCalendar(Locale.KOREA);
gc.setTime(c.getTime());
return c.get(Calendar.WEEK_OF_MONTH);
...

Date sunday = getSundayOfWeek(date);
return getYear(sunday);

Calendar calendar = Calendar.getInstance(locale);
calendar.setTime(date);
calendar.add(Calendar.WEEK_OF_MONTH, amount);
return calendar.getTime();