Handle empty responses properly

src/main/java/de/thm/arsnova/dao/CouchDBDao.java

@@ -1007,13 +1007,13 @@ public class CouchDBDao implements IDatabaseDao {
 	@Override
 	public List<Answer> getFreetextAnswers(String questionId) {
 		try {
+			List<Answer> answers = new ArrayList<Answer>();
 			View view = new View("skill_question/freetext_answers_full");
 			view.setKey(URLEncoder.encode("\"" + questionId + "\"", "UTF-8"));
 			ViewResults results = this.getDatabase().view(view);
 			if (results.getResults().isEmpty()) {
-				throw new NotFoundException();
+				return answers;
 			}
-			List<Answer> answers = new ArrayList<Answer>();
 			for (Document d : results.getResults()) {
 				Answer a = (Answer) JSONObject.toBean(d.getJSONObject().getJSONObject("value"), Answer.class);
 				a.setQuestionId(questionId);

src/main/java/de/thm/arsnova/services/QuestionService.java

@@ -229,7 +229,11 @@ public class QuestionService implements IQuestionService {
 	@Override
 	@Authenticated
 	public List<Answer> getFreetextAnswers(String questionId) {
-		return databaseDao.getFreetextAnswers(questionId);
+		List<Answer> answers = databaseDao.getFreetextAnswers(questionId);
+		if (answers == null) {
+			throw new NotFoundException();
+		}
+		return answers;
 	}
 
 	@Override