play框架list转jsonNode

`
List list = labelService.getNameBy();
List matchLabels = list.subList(1,3);
Gson gson = new Gson();
String comtext = gson.toJson(matchLabels);

ObjectMapper mapper = new ObjectMapper();
JsonNode rootNode = mapper.readTree(comtext);

ObjectNode result = Json.newObject();
result.put(“matchLables”, rootNode);
return ok(result);
`