java获得某一天的下一天

Calendar calendar = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
try {
calendar.setTime(sdf.parse(startTime));
} catch (ParseException e) {
e.printStackTrace();
}
calendar.add(Calendar.DAY_OF_YEAR, 1);
Date date = calendar.getTime();
String dayAfter = sdf.format(date));