import okhttp3.RequestBody;
import okhttp3.Response;

public class PostExample {
  public static final MediaType JSON = MediaType.get("application/json; charset=utf-8");

  final OkHttpClient client = new OkHttpClient();

  String post(String url, String json) throws IOException {
    RequestBody body = RequestBody.create(json, JSON);
    Request request = new Request.Builder()
        .url(url)
        .post(body)
        .build();

  private static final String ENDPOINT = "https://api.github.com/repos/square/okhttp/contributors";
  private static final Moshi MOSHI = new Moshi.Builder().build();
  private static final JsonAdapter<List<Contributor>> CONTRIBUTORS_JSON_ADAPTER = MOSHI.adapter(
      Types.newParameterizedType(List.class, Contributor.class));

  static class Contributor {
    String login;
    int contributions;
  }