How to log request and response body with Retrofit-Android?

Update for Retrofit 2.0.0-beta3

Now you have to use okhttp3 with builder. Also the old interceptor will not work. This response is tailored for Android.

Here's a quick copy paste for you with the new stuff.

1. Modify your gradle file to

  compile 'com.squareup.retrofit2:retrofit:2.0.0-beta3'
  compile "com.squareup.retrofit2:converter-gson:2.0.0-beta3"
  compile "com.squareup.retrofit2:adapter-rxjava:2.0.0-beta3"
  compile 'com.squareup.okhttp3:logging-interceptor:3.0.1'

2. Check this sample code:

with the new imports. You can remove Rx if you don't use it, also remove what you don't use.

import okhttp3.OkHttpClient;
import okhttp3.logging.HttpLoggingInterceptor;
import retrofit2.GsonConverterFactory;
import retrofit2.Retrofit;
import retrofit2.RxJavaCallAdapterFactory;
import retrofit2.http.GET;
import retrofit2.http.Query;
import rx.Observable;

public interface APIService {

  String ENDPOINT = "http://api.openweathermap.org";
  String API_KEY = "2de143494c0b2xxxx0e0";

  @GET("/data/2.5/weather?appid=" + API_KEY) Observable<WeatherPojo> getWeatherForLatLon(@Query("lat") double lat, @Query("lng") double lng, @Query("units") String units);


  class Factory {

    public static APIService create(Context context) {

      OkHttpClient.Builder builder = new OkHttpClient().newBuilder();
      builder.readTimeout(10, TimeUnit.SECONDS);
      builder.connectTimeout(5, TimeUnit.SECONDS);

      if (BuildConfig.DEBUG) {
        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        interceptor.setLevel(HttpLoggingInterceptor.Level.BASIC);
        builder.addInterceptor(interceptor);
      }

      //Extra Headers

      //builder.addNetworkInterceptor().add(chain -> {
      //  Request request = chain.request().newBuilder().addHeader("Authorization", authToken).build();
      //  return chain.proceed(request);
      //});

      builder.addInterceptor(new UnauthorisedInterceptor(context));
      OkHttpClient client = builder.build();

      Retrofit retrofit =
          new Retrofit.Builder().baseUrl(APIService.ENDPOINT).client(client).addConverterFactory(GsonConverterFactory.create()).addCallAdapterFactory(RxJavaCallAdapterFactory.create()).build();

      return retrofit.create(APIService.class);
    }
  }
}

Bonus

I know it's offtopic but I find it cool.

In case there's an http error code of unauthorized, here is an interceptor. I use eventbus for transmitting the event.

import android.content.Context;
import android.os.Handler;
import android.os.Looper;
import com.androidadvance.ultimateandroidtemplaterx.BaseApplication;
import com.androidadvance.ultimateandroidtemplaterx.events.AuthenticationErrorEvent;

import de.greenrobot.event.EventBus;
import java.io.IOException;
import javax.inject.Inject;
import okhttp3.Interceptor;
import okhttp3.Response;

public class UnauthorisedInterceptor implements Interceptor {

  @Inject EventBus eventBus;

  public UnauthorisedInterceptor(Context context) {
    BaseApplication.get(context).getApplicationComponent().inject(this);
  }

  @Override public Response intercept(Chain chain) throws IOException {
    Response response = chain.proceed(chain.request());
    if (response.code() == 401) {
      new Handler(Looper.getMainLooper()).post(() -> eventBus.post(new AuthenticationErrorEvent()));
    }
    return response;
  }
}

code take from https://github.com/AndreiD/UltimateAndroidTemplateRx (my project).

Retrofit 2.0 :

UPDATE: @by Marcus Pöhls

Logging In Retrofit 2

Retrofit 2 completely relies on OkHttp for any network operation. Since OkHttp is a peer dependency of Retrofit 2, you won’t need to add an additional dependency once Retrofit 2 is released as a stable release.

OkHttp 2.6.0 ships with a logging interceptor as an internal dependency and you can directly use it for your Retrofit client. Retrofit 2.0.0-beta2 still uses OkHttp 2.5.0. Future releases will bump the dependency to higher OkHttp versions. That’s why you need to manually import the logging interceptor. Add the following line to your gradle imports within your build.gradle file to fetch the logging interceptor dependency.

compile 'com.squareup.okhttp3:logging-interceptor:3.9.0'

You can also visit Square's GitHub page about this interceptor

Add Logging to Retrofit 2

While developing your app and for debugging purposes it’s nice to have a log feature integrated to show request and response information. Since logging isn’t integrated by default anymore in Retrofit 2, we need to add a logging interceptor for OkHttp. Luckily OkHttp already ships with this interceptor and you only need to activate it for your OkHttpClient.

HttpLoggingInterceptor logging = new HttpLoggingInterceptor();  
// set your desired log level
logging.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient.Builder httpClient = new OkHttpClient.Builder();   
// add your other interceptors …
// add logging as last interceptor
httpClient.addInterceptor(logging);  // <-- this is the important line!
Retrofit retrofit = new Retrofit.Builder()  
        .baseUrl(API_BASE_URL)
        .addConverterFactory(GsonConverterFactory.create())
        .client(httpClient.build())
        .build();

We recommend to add logging as the last interceptor, because this will also log the information which you added with previous interceptors to your request.

Log Levels

Logging too much information will blow up your Android monitor, that’s why OkHttp’s logging interceptor has four log levels: NONE, BASIC, HEADERS, BODY. We’ll walk you through each of the log levels and describe their output.

further information please visit : Retrofit 2 — Log Requests and Responses

OLD ANSWER:

no logging in Retrofit 2 anymore. The development team removed the logging feature. To be honest, the logging feature wasn’t that reliable anyway. Jake Wharton explicitly stated that the logged messages or objects are the assumed values and they couldn’t be proofed to be true. The actual request which arrives at the server may have a changed request body or something else.

Even though there is no integrated logging by default, you can leverage any Java logger and use it within a customized OkHttp interceptor.

further information about Retrofit 2 please refer : Retrofit — Getting Started and Create an Android Client

I used setLogLevel(LogLevel.FULL).setLog(new AndroidLog("YOUR_LOG_TAG")), it helped me.
UPDATE.
You can also try for debug purpose use retrofit.client.Response as response model