Converting POJO to JsonNode using a JsonView

Question

I'm writing a typical Play Framework app where I want to return a JsonNode from my Controller's methods, using Jackson.

This is how I'm doing it right now:

public static Result foo() {
   MyPojoType myPojo = new myPojo();
   String tmp = new ObjectMapper().writerWithView(JSONViews.Public.class).writeValueAsString(myPojo);
   JsonNode jsonNode = Json.parse(tmp);
   return ok(jsonNode);
}

Is it possible to avoid the "String tmp" copy and convert directly from MyPojoType to JsonNode using a view?

Maybe I can use ObjectMapper.valueToTree, but I don't know how to specify a JSonView to it.

Answer 1

Interesting question: off-hand, I don't think there is a specific method, and your code is the most straight-forward way to do it: valueToTree method does not apply any views. So code is fine as is.

Answer 2

After more investigation, this is what I did in the end to avoid the redundant work:

public Result toResult() {

    Content ret = null;

    try {
        final String jsonpayload = new ObjectMapper().writerWithView(JsonViews.Public.class).writeValueAsString(payload);

         ret = new Content() {
            @Override public String body() { return jsonpayload; }
            @Override public String contentType() { return "application/json"; }
        };
    } catch (JsonProcessingException exc) {
        Logger.error("toResult: ", exc);
    }

    if (ret == null)
        return Results.badRequest();

    return Results.ok(ret);
}

In summary: The methods ok, badRequest, etc accept a play.mvc.Content class. Then, simply use it to wrap your serialized json object.