@Autowired
ObjectMapper mapper;
@GetMapping(value = "/rest_json")
public @ResponseBody String restJson() throws IOException {
String json = "{\"name\":\"lijz\",\"id\":10}";
JsonNode node = mapper.readTree(json);
String name = node.get("name").asText();
Integer id = node.get("id").asInt();
return name+" "+id;
}