Jersey Message Filtering based on Author Name should return more than one value

Question

public Message getMessageByAuthor(String authorName) { 
    List<Message> nameList = new ArrayList<Message>(messages.values());
    Message message = null;
    if (!authorName.isBlank()) {
        Iterator<Message> iterator = nameList.iterator();
        while (iterator.hasNext()) {
            message = iterator.next();
            if (message.getMessageAuthor().contains(authorName)) {
                return message;
            }
        }
    }
    return message;
}

Answer 1

As Triby mentioned in the comment, you should create a new List and add the elements that match your criteria and then return the list so that you get more than one element if they match.

public List<Message> getMessageByAuthor(String authorName) { 
    List<Message> nameList = new ArrayList<Message>(messages.values());
    List<Message> responseMessageList = new ArrayList<>();
    Message message = null;
    if (!authorName.isBlank()) {
        Iterator<Message> iterator = nameList.iterator();
        while (iterator.hasNext()) {
            message = iterator.next();
            if (message.getMessageAuthor().contains(authorName)) {
                 responseMessageList.add(message);
            }
        }
    }
    return responseMessageList;
}