Java – play! The framework returns a JSON response

I use play! Framework 2.0 and I are new in this framework How to return only the JSON representation of my model in a white HTML page?

What am I doing

public static void messagesJSON(){  
   List<Message> messages = Message.all();  
   renderJSON(messages);  
}

But I received an error: you cannot use a method that returns unit as a handler

Solution

The method you use is from play 1 x. It is slightly different in play 2.0 From the documentation, the following is an example of how to reply to a sayhello JSON request

@BodyParser.Of(Json.class)
public static Result sayHello() {
  ObjectNode result = Json.newObject();
  String name = json.findPath("name").getTextValue();
  if(name == null) {
    result.put("status","KO");
    result.put("message","Missing parameter [name]");
    return badRequest(result);
  } else {
    result.put("status","OK");
    result.put("message","Hello " + name);
    return ok(result);
  }
}

Return an important part of the return OK (result) of a JSON objectnode