CODEWITHSUNDEEP
javajsonspringrestresttemplate
Eddie Romanenco
Eddie Romanenco

Reputation: 321

RestTemplate | Reading unknown ENUM values as default value

I'm using org.springframework:spring-web:5.1.9.RELEASE and have a plain (not customized) RestTemplate class object I use to send a POST request by utilizing the EXCHANGE method. I want to allow it desirialize unknown ENUM values from the response to their default value (as set using @JsonEnumDefaultValue) instead of failing the whole operation. I've searched and didn't find any easy way to do it, can you give me some help with that? Thanks!

@Service
@CommonsLog
public class TMServerExternalApiRepositoryImpl implements TMServerExternalApiRepository {
    private final RestTemplate restRelay;
    private TeleMessageProperties tmUrls;

    @Autowired
    public TMServerExternalApiRepositoryImpl(RestTemplate restTemplate, TeleMessageProperties tmProperties) {
        this.restRelay = restTemplate;
        this.tmUrls = tmProperties;
    }

    @Override
    public VnvUsersSearchResult getUsersByPhone(String to, String from) {
        log.info(String.format("Trying to get users with telephones to: [%s], from: [%s] ", to, from));
        return sendRequest(new VnvUserSearchParams(from, to), VnvUsersSearchResult.class, tmUrls.getGetUserByPhoneUrl()).getBody();
    }

    //the actual post
    private <T, K> ResponseEntity<T> sendRequest(K content, Class<T> returnTypeClass, String url) throws HttpClientErrorException {
        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON));
        httpHeaders.setContentType(MediaType.APPLICATION_JSON_UTF8);
        HttpEntity<K> httpEntity = new HttpEntity<>(content, httpHeaders);

        return restRelay.exchange(url, HttpMethod.POST, httpEntity, returnTypeClass);
    }
}

This is the exception I am getting now:

org.springframework.web.client.RestClientException: Error while extracting response for type [class voiceAndVideo.services.VnvUsersSearchResult] and content type [application/json]; nested exception is org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot deserialize value of type `voiceAndVideo.Util.VNVDevice$Type` from String "BAD_VALUE": value not one of declared Enum instance names: [MOBILE, ...]; nested exception is com.fasterxml.jackson.databind.exc.InvalidFormatException: Cannot deserialize value of type `voiceAndVideo.Util.VNVDevice$Type` from String "BAD_VALUE": value not one of declared Enum instance names: [MOBILE, ...]
 at [Source: (ByteArrayInputStream); line: 1, column: 261] (through reference chain: voiceAndVideo.services.VnvUsersSearchResult["userFrom"]->voiceAndVideo.Util.VNVUser["devices"]->java.util.ArrayList[2]->voiceAndVideo.Util.VNVDevice["type"])
    at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:117) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

Classes:

public class VnvUsersSearchResult {
    private VNVUser userFrom;
    ...
}

public class VNVUser {
    ...
    protected List<VNVDevice> devices;
    ...
}

public class VNVDevice {
    public Type type;
    String mobile;

    public enum Type {
        @JsonEnumDefaultValue
        UNKNOWN(0),
        MOBILE(10),
        BUSINESS_PHONE(20),
        ...

        int ID;

        Type(int i) {
            this.ID = i;
        }
    }
}

Upvotes: 0

Views: 3949

Answers (2)

Eddie Romanenco
Eddie Romanenco

Reputation: 321

I was able to solve it using JsonCreator placed in the ENUM class.

@JsonCreator
    public static Type getByValue(String t) {
        return Arrays.stream(Type.values())
                .filter(a -> a.name().equals(t)).findFirst().orElse(Type.UNKNOWN);
    }
}

Upvotes: 1

Shababb Karim
Shababb Karim

Reputation: 3733

You probably need to configure a custom ObjectMapper to the RestTemplate that you are using. You need to enable this feature on the ObjectMapper. Please make sure you are using fasterxml as the package for all these.

In order to configure one, create a JavaConfig file like this:

@Bean
public RestOperations restOperations() {
    RestTemplate rest = new RestTemplate();
    
    rest.getMessageConverters().add(0, mappingJacksonHttpMessageConverter());
    return rest;
}

@Bean
public MappingJacksonHttpMessageConverter mappingJacksonHttpMessageConverter() {
    MappingJacksonHttpMessageConverter converter = new MappingJacksonHttpMessageConverter();
    converter.setObjectMapper(myObjectMapper());
    return converter;
}

@Bean
public ObjectMapper myObjectMapper() {
    ObjectMapper mapper = new ObjectMapper();

    // This where you enable default enum feature
    objectMapper.configure(DeserializationFeature. READ_UNKNOWN_ENUM_VALUES_USING_DEFAULT_VALUE, true);

    return objectMapper;
}

Upvotes: 3

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