retrofit2 interceptor that logs the raw JSON response from API. After that it clones it and returns a sane copy that other classes can consume.

LogJsonInterceptor.java

import android.util.Log;

import com.appandweb.prjtestdrivendev.BuildConfig;
import com.squareup.okhttp.Interceptor;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;
import com.squareup.okhttp.ResponseBody;

import java.io.IOException;

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

        Response response = chain.proceed(request);
        String rawJson = response.body().string();

        Log.d(BuildConfig.APPLICATION_ID, String.format("raw JSON response is: %s", rawJson));

        // Re-create the response before returning it because body can be read only once
        return response.newBuilder()
                .body(ResponseBody.create(response.body().contentType(), rawJson)).build();
    }
}

Sample code to use this interceptor:

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

Update to make it work on retrofit 2.0.1 + okhttp3:

OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
httpClient.addInterceptor(new LogJsonInterceptor());
Retrofit retrofit = new Retrofit.Builder()
         .baseUrl(getEndPoint())
         .addConverterFactory(GsonConverterFactory.create())
         .client(httpClient.build())
         .build();

没必要制造额外的一个请求。

/**
 * HttpInterceptor
 */
public class HttpInterceptor implements Interceptor {
    private static final Charset UTF8 = Charset.forName("UTF-8");

    @Override
    public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();
        Logger.d(BuildConfig.APPLICATION_ID, "call ==> " + request.url());
        Response response = chain.proceed(request);
        ResponseBody responseBody = response.body();
        BufferedSource source = responseBody.source();
        source.request(Long.MAX_VALUE); // Buffer the entire body.
        Buffer buffer = source.buffer();
        Logger.d(BuildConfig.APPLICATION_ID, "ret ==> " + buffer.clone().readString(UTF8).toString());
        return response;
    }
}

可以参考HttpLoggingInterceptor源码

Many thanks for the tips but What about the request? How do we print log of the request in JSON?

This helps to format output more readable

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

        Response response = chain.proceed(request);
        String rawJson = response.body().string();

        try {
            Object object = new JSONTokener(rawJson).nextValue();
            String jsonLog = object instanceof JSONObject
                    ? ((JSONObject) object).toString(4)
                    : ((JSONArray) object).toString(4);
            Log.d("jsonLog", jsonLog);
        } catch (JSONException e) {
            e.printStackTrace();
        }

        // Re-create the response before returning it because body can be read only once
        return response.newBuilder()
                .body(ResponseBody.create(response.body().contentType(), rawJson)).build();
    }
}

Thanks so much sir You save My time

Thanks a lot, saved me the trouble

This solution working Thanks. @thanhbinh84

没必要制造额外的一个请求。

/**
 * HttpInterceptor
 */
public class HttpInterceptor implements Interceptor {
    private static final Charset UTF8 = Charset.forName("UTF-8");

    @Override
    public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();
        Logger.d(BuildConfig.APPLICATION_ID, "call ==> " + request.url());
        Response response = chain.proceed(request);
        ResponseBody responseBody = response.body();
        BufferedSource source = responseBody.source();
        source.request(Long.MAX_VALUE); // Buffer the entire body.
        Buffer buffer = source.buffer();
        Logger.d(BuildConfig.APPLICATION_ID, "ret ==> " + buffer.clone().readString(UTF8).toString());
        return response;
    }
}

可以参考HttpLoggingInterceptor源码

Hi @aliang228, regarding your code proposal. Couldn't this Long.MAX_VALUE be improved? according to .request() documentation:

  /**
   * Returns true when the buffer contains at least {@code byteCount} bytes, expanding it as
   * necessary. Returns false if the source is exhausted before the requested bytes can be read.
   */
  boolean request(long byteCount) throws IOException;

This means that you would be requesting a buffer of 9.223.372.036.854.775.807 bytes on every HTTP request intercepted by this HttpInterceptor. Do you find this reasonable? or could it be improved?

Thanks for the proposal!

thank you