code: private static Date checkSameDate(final List<VoteDataDto> voteList) throws ParseException {
  		final Set<String> set = new HashSet<>();
  		Date result=null;
  
  		for (final VoteDataDto voteData : voteList) {
  			final String voteDate = voteData.getVoteDate();
  			if (voteDate !=null && voteDate.length() >= YYYY_MM_DD.length()) {
  				set.add(voteData.getVoteDate());
  			}
  		}
  
  		if (set.size() ==CONTAINS_ONE) {
  			final String dateString = set.iterator().next();
  			result=new SimpleDateFormat(YYYY_MM_DD,Locale.ENGLISH).parse(dateString);
  		}
  		return result;
  	}
docs: Check same date.
  
  @param voteList
  the vote list
  @return the date
  @throws ParseException
  the parse exception