Gson converter is broken when converting string response body

[NeoLSN]

See the log.

01-14 11:36:42.987 11795-13040/com.example.app D/OkHttp: <-- 200 OK api_web (7364ms)
01-14 11:36:42.987 11795-13040/com.example.app D/OkHttp: Content-Type: application/json; charset=UTF-8
01-14 11:36:42.987 11795-13040/com.example.app D/OkHttp: Date: Thu, 14 Jan 2016 03:36:37 GMT
01-14 11:36:42.987 11795-13040/com.example.app D/OkHttp: Server: Apache
01-14 11:36:42.987 11795-13040/com.example.app D/OkHttp: Status: 200 OK
01-14 11:36:42.987 11795-13040/com.example.app D/OkHttp: Content-Length: 94
01-14 11:36:42.987 11795-13040/com.example.app D/OkHttp: Connection: keep-alive
01-14 11:36:42.987 11795-13040/com.example.app D/OkHttp: OkHttp-Sent-Millis: 1452742596982
01-14 11:36:42.987 11795-13040/com.example.app D/OkHttp: OkHttp-Received-Millis: 1452742602997
01-14 11:36:42.987 11795-13040/com.example.app D/OkHttp: "0qQ9imBV5zYCZi5NRIZCl9WCivkSjj5SR5Ya8Diw0Urw6RV0hoef_DqaNgcZyPif4C89eAFZGn80p8xWroRnEn3AJhPL"
01-14 11:36:42.987 11795-13040/com.example.app D/OkHttp: <-- END HTTP (94-byte body)
01-14 11:36:42.997 11795-13040/com.example.app D/ExoLibrary: error occur
                                                             com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 2 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:575)
                                                                 at com.google.gson.stream.JsonReader.peek(JsonReader.java:429)
                                                                 at com.google.gson.internal.bind.TypeAdapters$13.read(TypeAdapters.java:351)
                                                                 at com.google.gson.internal.bind.TypeAdapters$13.read(TypeAdapters.java:348)
                                                                 at com.google.gson.TypeAdapter.fromJson(TypeAdapter.java:260)
                                                                 at retrofit2.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:33)
                                                                 at retrofit2.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:23)
                                                                 at retrofit2.OkHttpCall.parseResponse(OkHttpCall.java:154)
                                                                 at retrofit2.OkHttpCall.execute(OkHttpCall.java:118)

The library based on

    compile 'com.squareup.retrofit2:retrofit:2.0.0-beta3'
    compile 'com.squareup.retrofit2:converter-gson:2.0.0-beta3'
    compile 'com.squareup.okhttp3:okhttp:3.0.0-RC1'
    compile 'com.squareup.okhttp3:okhttp-urlconnection:3.0.0-RC1'
    compile 'com.squareup.okhttp3:logging-interceptor:3.0.0-RC1'

[NeoLSN]

I do the simple test like below

    Gson gson = new Gson();
    TypeAdapter<String> adapter = gson.getAdapter(TypeToken.get(String.class));
    Reader reader = new StringReader("0qQ9imBV5zYCZi5NRIZCl9WCivkSjj5SR5Ya8Diw0Urw6RV0hoef_DqaNgcZyPif4C89eAFZGn80p8xWroRnEn3AJhPL");
    String str = adapter.fromJson(reader);
    Log.d("Debug", "str = "+str);

The same problem happened again.
But when I changed to

    Gson gson = new Gson();
    Reader reader = new StringReader("0qQ9imBV5zYCZi5NRIZCl9WCivkSjj5SR5Ya8Diw0Urw6RV0hoef_DqaNgcZyPif4C89eAFZGn80p8xWroRnEn3AJhPL");
    String str = gson.fromJson(reader, String.class);
    Log.d("Debug", "str = "+str);

It goes safe.

[JakeWharton]

This is actually a Gson bug in not supporting this from RFC 7159 in its strict mode. However, supporting a way to enable lenient mode in Gson is the Retrofit bug here.

[JakeWharton]

First step: google/gson#771. Once Gson has a release we can consume the newJsonReader API just like we do newJsonWriter to provide lenient parsing.

[JakeWharton]

And here's the fix in Gson (google/gson#773) and Moshi (square/moshi#121) for supporting top-level value types.

[andreaturli]

is there a way to test it using a new moshi release?
or we need to wait for new Gson release to have a retrofit beta4 ?
Thanks!

[JakeWharton]

For Gson it still requires an update to Retrofit to use its new API. For Moshi, once its v1.1 released (hopefully today, maybe tomorrow), all that is needed is ensuring you are using its latest version with any version of Retrofit.

[andreaturli]

thanks for the update!

[JakeWharton]

FYI Gson 2.6.1 was released with RFC 7159 support which should allow this to work with any version of Retrofit without needing Gson to be set to lenient.

That said, I'm still adding support for honoring leniency in Retrofit's Gson converter (and using this issue to track).

[NeoLSN]

Great news about this. Thanks.