Deserialize LocalDate

530

18 апреля 2018, 08:57

Всем привет! Есть Restful вебсервис написанный с Spring Boot, который отдает entity с полем LocalDate с контроллера. И есть клиент для него на Андроиде, но проблема в том, что при попытке получить ответ вылетает ошибка, что не может десериализовать LocalDate. Попробовала решение - написать кастомный Deserializer и прописать соответствующую аннотацию над полем класса, но не сработало. Можно ли вообще эту проблему решить не со стороны сервера, а со стороны клиента?

Код десериализатора:

public class LocalDateDeserializerImpl extends StdDeserializer<LocalDate> {
    public LocalDateDeserializerImpl() {
        super(LocalDate.class);
    }
    @Override
    public LocalDate deserialize(JsonParser parser, DeserializationContext ctxt) throws IOException, JsonProcessingException {
        return LocalDate.parse(parser.readValueAs(String.class));
    }
}

Код контроллера:

@RestController
@AllArgsConstructor
class EmployeeRequestController {
    @GetMapping(value = "/employee-requests/username/{username}")
    List<EmployeeRequestResponse> getDaysWithDecision(
            @PathVariable("username") String username,
            @RequestParam(required = false)
            @DateTimeFormat(iso = DATE) LocalDate date
    ) {
        return employeeRequestService.getDatesWithEmployeeRequestStatuses(username, date);
    }
}

Сама сущность:

@Builder
@Value
public class EmployeeRequestResponse {
    String username;
    @JsonDeserialize(using = LocalDateDeserializerImpl.class)
    LocalDate date;
    RequestStatus requestStatus;
}

Код в клиенте:

private class DaysTask extends AsyncTask<Void, Void, EmployeeRequestResponse[]> {
        @Override
        protected EmployeeRequestResponse[] doInBackground(Void... voids) {
            HttpHeaders httpHeaders = new HttpHeaders();
            httpHeaders.setAccept(Arrays.asList(new MediaType[]{MediaType.APPLICATION_JSON}));
            httpHeaders.setContentType(MediaType.APPLICATION_JSON);
            HttpEntity<EmployeeRequestResponse[]>httpEntity = new HttpEntity<>(httpHeaders);
            RestTemplate template = new RestTemplate();
            template.getMessageConverters().add(new MappingJackson2HttpMessageConverter());
            EmployeeRequestResponse[] data2 = template.getForObject(Constants.URL.GET_DATES_FOR_EMPLOYEE, EmployeeRequestResponse[].class);
            return data2;
}

Вот что с сервера приходит

E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
                  Process: appname, PID: 12352
                  java.lang.RuntimeException: An error occurred while executing doInBackground()
                      at android.os.AsyncTask$3.done(AsyncTask.java:353)
                      at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:383)
                      at java.util.concurrent.FutureTask.setException(FutureTask.java:252)
                      at java.util.concurrent.FutureTask.run(FutureTask.java:271)
                      at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245)
                      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
                      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
                      at java.lang.Thread.run(Thread.java:764)
                   Caused by: org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Cannot construct instance of `appname.EmployeeRequestResponse` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('2018-04-17')
                      at [Source: (com.android.okhttp.okio.RealBufferedSource$1); line: 1, column: 2] (through reference chain: java.lang.Object[][0]); nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `appname.EmployeeRequestResponse` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('2018-04-17')
                      at [Source: (com.android.okhttp.okio.RealBufferedSource$1); line: 1, column: 2] (through reference chain: java.lang.Object[][0])
                      at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.readInternal(MappingJackson2HttpMessageConverter.java:126)
                      at org.springframework.http.converter.AbstractHttpMessageConverter.read(AbstractHttpMessageConverter.java:147)
                      at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:76)
                      at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:484)
                      at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:439)
                      at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:237)
                      at appname.MainActivity$DaysTask.doInBackground(MainActivity.java:136)
                      at appname.MainActivity$DaysTask.doInBackground(MainActivity.java:127)
                      at android.os.AsyncTask$2.call(AsyncTask.java:333)
                      at java.util.concurrent.FutureTask.run(FutureTask.java:266)
                      at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245) 
                      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162) 
                      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636) 
                      at java.lang.Thread.run(Thread.java:764) 
                   Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `appname.EmployeeRequestResponse` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('2018-04-17')
                      at [Source: (com.android.okhttp.okio.RealBufferedSource$1); line: 1, column: 2] (through reference chain: java.lang.Object[][0])
                      at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1342)
                      at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1031)
                      at com.fasterxml.jackson.databind.deser.ValueInstantiator._createFromStringFallbacks(ValueInstantiator.java:371)
                      at com.fasterxml.jackson.databind.deser.std.StdValueInstantiator.createFromString(StdValueInstantiator.java:323)
                      at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromString(BeanDeserializerBase.java:1366)
                      at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:171)
                      at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:161)
                      at com.fasterxml.jackson.databind.deser.std.ObjectArrayDeserializer.deserialize(ObjectArrayDeserializer.java:195)
                      at com.fasterxml.jackson.databind.deser.std.ObjectArrayDeserializer.deserialize(ObjectArrayDeserializer.java:21)
                      at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4001)
                      at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3072)
                      at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.readInternal(MappingJackson2HttpMessageConverter.java:123)

Answer 1

Такое в общем нашла решение, может корявое но работает. Просто напрямую считываю строки с Json-а и конвертирую как мне надо

private class DaysTask extends AsyncTask<Void, Void, LocalDate>{
        @Override
        protected LocalDate doInBackground(Void... voids) {
            LocalDate date = null;
            try {
                URL url = new URL(Constants.URL.GET_DATES_FOR_EMPLOYEE);
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setRequestMethod("GET");
                InputStream responseBody = connection.getInputStream();
                InputStreamReader responseBodyReader =
                        new InputStreamReader(responseBody, "UTF-8");
                JsonReader jsonReader = new JsonReader(responseBodyReader);
                jsonReader.setLenient(true);
                while (jsonReader.peek().equals(JsonToken.STRING)) {
                    String line = jsonReader.nextString();
                    date = LocalDate.parse(line, DateTimeFormatter.ISO_LOCAL_DATE);
                    break;
                }
                jsonReader.close();
                connection.disconnect();
            } catch (MalformedURLException e) {
                e.printStackTrace();
            }catch (IOException e){
                e.printStackTrace();
            }
            return date;
        }

Всем спасибо кто откликнулся и пытался помочь) Доброго всем дня!=)))