java - Retrofit and OkHttp gzip decode

Question

The REST service I want to consume answers as a gzipped encoded JSON. It provides the Content-Encoding: gzip, but my OkHttp does not encode it to readable text, so the JSON converter throws an exception.

---> HTTP GET https://rapla.dhbw-karlsruhe.de/rapla/events?resources=%5B%27rc85dbd6-7d98-4eb7-a7f6-b867213c73d8%27%5D&start=2015-09-01&end=2015-12-31
Accept-Encoding: gzip, deflate
Accept: application/json
Authorization: *not posted*
Content-Type: application/json;charset=utf-8
---> END HTTP (no body)
<--- HTTP 200 https://rapla.dhbw-karlsruhe.de/rapla/events?resources=%5B%27rc85dbd6-7d98-4eb7-a7f6-b867213c73d8%27%5D&start=2015-09-01&end=2015-12-31 (13ms)
Date: Tue, 24 Nov 2015 09:09:10 GMT
Server: Jetty(9.2.2.v20140723)
Expires: Tue, 01 Jan 1980 00:00:00 GMT
Pragma: no-cache
Cache-Control: no-cache, must-revalidate
Content-Encoding: gzip
Content-Type: application/json; charset=utf-8
Content-Disposition: attachment
Content-Length: 9684
Via: 1.1 rapla.dhbw-karlsruhe.de
Keep-Alive: timeout=5, max=99
Connection: Keep-Alive
OkHttp-Selected-Protocol: http/1.1
OkHttp-Sent-Millis: 1448356149978
OkHttp-Received-Millis: 1448356149991

????WK?{??J?`k?_??Z????E?p?>3m?WMa?????p?0??<??
... skipped rest of the body
E??>???S???n 
<--- END HTTP (9684-byte body)

According to Jake Whartons comment the Content-Encoding: gzip Header should tell OkHttp to decode the body.

The code for creating the RestAdapter is:

final RestAdapter adapter = new RestAdapter.Builder()
    .setEndpoint(baseUrl)
    .setClient(new OkClient(new OkHttpClient()))
    .setConverter(new GsonConverter(gson))
    .setLogLevel(RestAdapter.LogLevel.FULL)
    .build();
service = adapter.create(RaplaService.class);

The gradle dependencies are:

compile 'com.squareup.retrofit:retrofit:1.9.0'
compile 'com.squareup.okhttp:okhttp:2.6.0'

The method in my ServiceInterface:

@Headers({
        "Accept-Encoding: gzip, deflate",
        "Content-Type: application/json;charset=utf-8",
        "Accept: application/json"
})
@GET("/events")
List<Event> getEvents(@Header("Authorization") String token, @Query("resources") String resources, @Query("start") String start, @Query("end") String end);

Answer 1

Replace this:

@Headers({
    "Accept-Encoding: gzip, deflate",
    "Content-Type: application/json;charset=utf-8",
    "Accept: application/json"
})

With this:

@Headers({
    "Content-Type: application/json;charset=utf-8",
    "Accept: application/json"
})

When you provide your own Accept-Encoding header you’re instructing OkHttp that you want to do your own decompression. By omitting it, OkHttp will take care of both adding the header and the decompression.