Why does Spring MVC report “No converter found for return value of type: class org.json.JSONObject”?

Question

I want to return a JSON made of two strings and don\'t know how to implement it. Here is my code:

 @PostMapping
public ResponseEntity<> createUser(@Request         


        

Answer 1

Jackson does not know about org.json.JSONObject, use JsonNode instead for key/value pair.

Update after comment:

Could you write me an example how would you use it? I find it a bit confusing

@PostMapping
public ResponseEntity createUser(@RequestBody User user) {
        ObjectMapper objectMapper = new ObjectMapper();

        Map responseJson = new HashMap<>();
        if (userService.userExists(user)) {
            responseJson.put("status",
                    "User with that username already exists.");
            JsonNode jsonNode = objectMapper.valueToTree(responseJson);
            return new ResponseEntity(jsonNode,
                    HttpStatus.BAD_REQUEST);
        }
        responseJson.put("status", "User created.");
        JsonNode jsonNode = objectMapper.valueToTree(responseJson);
        return new ResponseEntity<>(jsonNode, HttpStatus.CREATED);
}