android - Retrofit2.0 gets MalformedJsonException while the json seems correct?

Question

I am using retrofit:2.0.0-beta4 for my android app.

I tried to add a user with Retrofit, the user is correctly created in Database, however I got the following error:

03-14 06:04:27.731 30572-30600/com.lehuo.lehuoandroid D/OkHttp: CALLING POST SP_User_CreateUser....your new user_id:48
{"data":{"user_id":"48","nickname":null,"password":null,"status":null},"status":1,"msg":"OK"}
03-14 06:04:27.731 30572-30600/com.lehuo.lehuoandroid D/OkHttp: <-- END HTTP (147-byte body)
03-14 06:04:27.732 30572-30600/com.lehuo.lehuoandroid E/My?Jobs: error while executing job
     com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $
         at com.google.gson.stream.JsonReader.syntaxError(JsonReader.java:1573)
         at com.google.gson.stream.JsonReader.checkLenient(JsonReader.java:1423)
         at com.google.gson.stream.JsonReader.doPeek(JsonReader.java:587)
         at com.google.gson.stream.JsonReader.peek(JsonReader.java:429)
         at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:202)
         at com.google.gson.TypeAdapter.fromJson(TypeAdapter.java:260)
         at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:32)
         at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:23)
         at retrofit2.OkHttpCall.parseResponse(OkHttpCall.java:213)
         at retrofit2.OkHttpCall.execute(OkHttpCall.java:177)
         at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall.execute(ExecutorCallAdapterFactory.java:87)
         at com.lehuo.lehuoandroid.async.NetworkJob.callNet(NetworkJob.java:30)
         at com.lehuo.lehuoandroid.async.CreateUserJob.onRun(CreateUserJob.java:34)
         at com.path.android.jobqueue.BaseJob.safeRun(BaseJob.java:108)
         at com.path.android.jobqueue.JobHolder.safeRun(JobHolder.java:60)
         at com.path.android.jobqueue.executor.JobConsumerExecutor$JobConsumer.run(JobConsumerExecutor.java:201)
         at java.lang.Thread.run(Thread.java:818)

The returned result from server is :

{"data":{"user_id":"48","nickname":null,"password":null,"status":null},"status":1,"msg":"OK"}

This is correct json format, I don't understand why I get such exception?

Here us my interface:

public class ApiResult<T> {
    public T data;
    public int status;
    public String msg;
}

public interface ApiUsers {
    @POST("/users/new")
    public Call<ApiResult<User>> createUser(@Body User user);
}

public class User {
    public int user_id;
    public String registration;
    public int registration_type;
    public String avatar;
    public String nickname;
    public String password;
    public String status;

}

public class Api {

    // TODO modify the value
    public static final String BASE_URL = "xxx";

    private static Api instance = new Api();

    public static Api getInstance() {
        return instance;
    }

    private Api(){}

    public Retrofit getRetrofit() {
        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
        OkHttpClient client = new OkHttpClient.Builder()
                .addInterceptor(interceptor)
                .retryOnConnectionFailure(true)
                .connectTimeout(15, TimeUnit.SECONDS)
                .build();

        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(BASE_URL)
                .client(client)
                .addConverterFactory(GsonConverterFactory.create())
                .build();

        return retrofit;
    }

    public <S> S createService(Class<S> serviceClass) {
        return getRetrofit().create(serviceClass);
    }
}

The caller code is:

ApiUsers api = Api.getInstance().createService(ApiUsers.class);
Call<ApiResult<User>> call = api.createUser(user);
CreateUserMessage message = new CreateUserMessage();
callNet(call, message);

Could anyone give any clue?

Answer 1

Finally I solved my problem which is not related to the json lenient mode, something wrong with my POST response (there some other non json output before the json data).

Here is the response from JakeWharton regarding how to set Gson lenient mode:

make sure that you have：compile 'com.google.code.gson:gson:2.6.1'

Gson gson = new GsonBuilder()
        .setLenient()
        .create();

Retrofit retrofit = new Retrofit.Builder()
        .baseUrl(BASE_URL)
        .client(client)
        .addConverterFactory(GsonConverterFactory.create(gson))
        .build();