I am a beginner of Java & Springboot. I feel like I am doing something that does not use the full strength of spring boot, e.g. using JsonNode & return untyped Response Entity etc.

Just wonder if there is any best practice when dealing with this kind of situation, when I want to return an object as part of result.

In Typescript I can create an interface for the object, how about in java / Springboot?

TestService.java

...
@Service
@Slf4j
public class TestService {
    private final TsKvRepository tsKvRepository;
    private final ObjectMapper objectMapper = new ObjectMapper();

    @Autowired
    public TestService(TsKvRepository tsKvRepository) {
        this.tsKvRepository = tsKvRepository;
    }

    public DeferredResult<ResponseEntity> getLatestTimeseries(String entityIdStr, String eui64) {
        DeferredResult<ResponseEntity> result = new DeferredResult<>();

        try {
            UUID entityId = UUID.fromString(entityIdStr);
            List<TsKvEntity> tsList =  this.tsKvRepository.findLatestByEui64(entityId, eui64);

            if (!tsList.isEmpty()) {
                TsKvEntity tsKvEntity = tsList.get(0);
                JsonNode jsonNode = objectMapper.readTree(tsKvEntity.getJsonValue());
                
                ResponseEntity<?> responseEntity = new ResponseEntity<>(jsonNode.get(0), HttpStatus.OK);
                result.setResult(responseEntity);
            } else {
                ResponseEntity<?> responseEntity = new ResponseEntity<>("No data found", HttpStatus.NOT_FOUND);
                result.setResult(responseEntity);
            }

        }catch(IllegalArgumentException | NullPointerException e) {
            ResponseEntity<?> responseEntity = new ResponseEntity<>("Invalid UUID format or null keysStr: " + e.getMessage(), HttpStatus.BAD_REQUEST);
            result.setResult(responseEntity);
        } catch (JsonMappingException e) {
            throw new RuntimeException(e);
        } catch (JsonProcessingException e) {
            throw new RuntimeException(e);
        }
        return result;
    }

}