java 时间加法

public static void main(String[] args) {

    LocalTime time = LocalTime.parse("21:53:00");

    LocalTime augment = LocalTime.parse("01:50:22");

    LocalTime time2 = plusTime(time, augment);

    System.out.println("time2: " + time2);
}


private static LocalTime plusTime(LocalTime current, LocalTime augment) {
    Duration duration = Duration.between(START, augment);
    return current.plus(duration);
}

SimpleDateFormat formatter = new SimpleDateFormat(ddcx.getKssj());
SimpleDateFormat formatter2 = new SimpleDateFormat(ddcx.getJssj());
SimpleDateFormat formatter3= new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date four = null;
Date four2 = null;
Date now = new Date();
try {
    four = formatter3.parse(formatter.format(now) + " 00:00:00");
    four2 = formatter3.parse(formatter2.format(now) + " 23:59:59");
} catch (ParseException e) {
    e.printStackTrace();
}

SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String kssj = sdf.format(four);
String jssj = sdf.format(four2);