Retrofit 2 - Is it possible to get the size of a JSON that I'm sending and receiving?

Question

I need to build a traffic monitor on my Android app, and I need to have stored the size of all json that I'm sending and receiving through retrofit. Using log I can see the actual size of it, but I haven't find a way to get this information so I could save it. I can't get the response.raw either since it's already been parsed to my classes. Is there any way to achieve that?

EDIT: Marked vadkou answer as the best one.

Instead of creating a new interceptor, I passed the lamda expression:

 httpClient.addInterceptor( chain -> {
        okhttp3.Request request = chain.request();
        okhttp3.Response response = chain.proceed(request);
        if(request.body()!=null) {
            long requestLength = request.body().contentLength();
            Log.e("SERVICE GENERATOR", " CONTENT LENGTH" + requestLength);

        }
        long responseLength = response.body().contentLength();
        Log.e("SERVICE GENERATOR", " RESPONSE LENGTH" + responseLength);

        return response;

    });

vadkou · Accepted Answer · 2017-06-19T15:07:00.473

4

Retrofit 2 uses OkHttp internally, and you could configure OkHttp without having to resort to getting raw HTTP response as in Vaiden's answer by adding a custom Interceptor while building an adapter as follows:

private Retrofit createRetrofit() {
       return new Retrofit.Builder()
            .baseUrl(END_POINT)
       //     .addConverterFactory(...)
       //     .addCallAdapterFactory(...)
            .client(createClient())
            .build();
}

private OkHttpClient createClient() {
        OkHttpClient.Builder okHttpClientBuilder = new OkHttpClient.Builder();
        okHttpClientBuilder.addInterceptor(createYourInterceptor());
        return okHttpClientBuilder.build();
}

The Interceptor interface among other things allows you to access request body for every request you make.

@Override
public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();
            // do what you want with request.body().contentLength();
        return chain.proceed(request);
}

edited Jun 19 '17 at 15:07

answered Jun 19 '17 at 11:49

vadkou

300
2
8

Niiiiiiiiiiiiice – Vaiden Jun 19 '17 at 12:00
I tried that, but the Request body is returning null and the contentLength() of the response always returns -1 everytime I log it. This is my lambda expression on the http interceptor. **httpClient.addInterceptor( chain -> { okhttp3.Request request = chain.request(); okhttp3.Response response = chain.proceed(request); long requestLength = request.body().contentLength(); long responseLength = response.body().contentLength(); return response; });** – julioribeiro Jun 19 '17 at 13:49
@julioribeiro what converter did you use? – vadkou Jun 19 '17 at 14:59
GsonConverterFactory. I don't use nothing special than this. Just build my RefrotiBuilder with the baseUrl, GsonConverterFactory, add loggin interceptor and now this lamda as a new interceptor. – julioribeiro Jun 19 '17 at 15:41
@julioribeiro could you check if the server actually receives any POST data? Perhaps a `@Body` annotation is missing on a method parameter. Also, as you are using Logging Interceptor, you should see the JSON body in logcat – vadkou Jun 19 '17 at 15:43
@vadkou Sorry for the delay, So on every POST that I make I'm able to get the Request Length with it's correct size. But response is always -1. When I perform a GET, my request is null and response is -1 as well. – julioribeiro Jun 19 '17 at 17:04
@julioribeiro Retrofit doesn't support request bodies with GET by default for reasons argued [in this topic](https://stackoverflow.com/questions/978061/http-get-with-request-body/983458). If you don't have any control over the API, you might work around it with a custom annotation `@Target(METHOD) @Retention(RUNTIME) @RestMethod(value = "GET", hasBody = true) public @interface GET { String value(); }` Also I think this conversation qualifies for being "an extended discussion", and we should rather open a chat room and have all comments moved there somehow. – vadkou Jun 19 '17 at 17:47

score 2 · Answer 2 · answered Jun 19 '17 at 12:26

For this you need to create custom interecptor please reffere below example

import java.io.IOException; 
import okhttp3.Interceptor;
import okhttp3.Request;
import okhttp3.Response;


public class CustomIntercepter implements Interceptor {
    @Override
    public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();///
        Response response = chain.proceed(request);


        // for request size 

        long requestLength = request.body().contentLength();

        // for response size 
        long responseLength = response.body().contentLength();


        return response;
    }
}

`

Now Create Retrofit object

OkHttpClient provideOkHttpClient(CustomIntercepter customIntercepter) {
    OkHttpClient.Builder okHttpClient = new OkHttpClient.Builder();
    okHttpClient.cache(cache);
    okHttpClient.addInterceptor(customIntercepter);
    return okHttpClient.build();
}


Retrofit provideRetrofit(Gson gson, OkHttpClient okHttpClient) {
    Retrofit retrofit = new Retrofit.Builder()
            .addConverterFactory(GsonConverterFactory.create(gson))
            .baseUrl(SERVER_URL)
            .client(okHttpClient)
            .build();
    return retrofit;
}

How is this different from my answer? – vadkou Jun 19 '17 at 15:03 — vadkou, Jun 19 '17 at 15:03

score 1 · Answer 3 · answered Jun 19 '17 at 11:48

You should try accessing the raw HTTP response (Get raw HTTP response with Retrofit):

You begin with a Response object.

This object has a .raw() method that returns the actual HTTP layer's reponse, in the form of an okhttp3.Response object. Calling .body() would give you a ResponseBody object, which encapsulates the raw response.

You can get the length of the response by calling .contentLength().

Retrofit 2 - Is it possible to get the size of a JSON that I'm sending and receiving?

3 Answers3

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