Retrofit 2 logging

ClientCreator.java

OkHttpClient createClient() {
  final OkHttpClient client = new OkHttpClient();
  // ...
  client.networkInterceptors().add(chain -> {
    Request request = chain.request();
    if (DEBUG) {
      log(request);
    } else {
      String protocolPrefix = request.isHttps() ? "S" : "";
      Log.i(TAG, String.format("---> HTTP%s %s %s", 
          protocolPrefix, request.method(), request.urlString()));
    }

    long start = System.nanoTime();
    Response response = chain.proceed(request);
    long elapsedTime = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start);

    if (DEBUG) {
      return log(request.urlString(), response, elapsedTime);
    } else {
      Log.i(TAG, String.format("<--- HTTP %s %s (%sms)",
          response.code(), request.urlString(), elapsedTime));
    }
    return response;
  });
  // ...
  return client;
}

void log(Request r) throws IOException {
  final Request request = r.newBuilder().build();
  String protocolPrefix = request.isHttps() ? "S" : "";
  Log.d(TAG,
      String.format("---> HTTP%s %s %s", protocolPrefix, request.method(),
          request.urlString()));

  Headers headers = request.headers();
  for (String header : headers.names()) {
    Log.d(TAG, String.format("%s: %s", header, headers.get(header)));
  }

  String bodySize = "no";
  RequestBody body = request.body();
  if (body != null) {
    MediaType bodyMime = body.contentType();
    if (bodyMime != null) {
      Log.d(TAG, "Content-Type: " + bodyMime);
    }

    long bodyLength = body.contentLength();
    bodySize = bodyLength + "-byte";
    if (bodyLength != -1) {
      Log.d(TAG, "Content-Length: " + bodyLength);
    }
    if (headers.size() > 0) {
      Log.d(TAG, "\n");
    }
    Buffer sink = new Buffer();
    body.writeTo(sink);
    if (bodyMime != null) {
      Log.d(TAG, sink.readUtf8());
    }
  }
  Log.d(TAG, String.format("---> END HTTP%s (%s body)", protocolPrefix, bodySize));
}

private Response log(String url, Response response, long elapsedTime)
      throws IOException {
  Response.Builder builder = response.newBuilder();
  Log.d(TAG, String.format("<--- HTTP %s %s (%sms)", response.code(), url, elapsedTime));
  Headers headers = response.headers();
  for (String header : headers.names()) {
    Log.d(TAG, String.format("%s: %s", header, headers.get(header)));
  }
  ResponseBody body = response.body();
  byte[] source = body.bytes();
  MediaType mediaType = body.contentType();
  builder.body(ResponseBody.create(mediaType, source));
  if (headers.size() > 0) {
    Log.d(TAG, "");
  }
  Charset defaultCharset = Charset.forName("UTF-8");
  Charset charset = mediaType != null ? mediaType.charset() != null ? mediaType.charset()
      : defaultCharset : defaultCharset;
  Log.d(TAG, new String(source, charset));
  Log.d(TAG, String.format("<--- END HTTP (%s-byte body)", body.contentLength()));
  return builder.build();
}