java 获取本周开始时间

public static String getWeekStart() {
        LocalDate d1=LocalDate.now();
        String d2= d1.getDayOfWeek().getDisplayName(TextStyle.FULL, Locale.CHINESE);
        if("星期一".equals(d2)){
            Date date = new Date();
            Calendar  currentDate = Calendar.getInstance();
            currentDate.setTime(date);
            if (1 == currentDate.get(Calendar.DAY_OF_WEEK)) {
                currentDate.add(Calendar.DATE, -1);
            }
            currentDate.add(Calendar.DAY_OF_MONTH, -7);
            currentDate.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
            return dateFormat.format(currentDate.getTime());
        } else {
            Calendar currentDate = Calendar.getInstance();
            currentDate.setFirstDayOfWeek(Calendar.MONDAY);
            currentDate.set(Calendar.HOUR_OF_DAY, 0);
            currentDate.set(Calendar.MINUTE, 0);
            currentDate.set(Calendar.SECOND, 0);
            currentDate.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
            return dateFormat.format(currentDate.getTime());
        }
}