How to send a request to the server using the library Retrofit

The situation is the following, you need to send POST to the server using http basic auth. The data that you need to send must be json, type

{ "value1": [ { "value2": "param1", "value3": "param2" } ] } 

Is it possible to simply make this json, toString (), and transfer to the server, or is there a mechanism for Retrofit for this, and tell me about basic auth, maybe what I am doing wrong.

This is in the Api class.

  public void getUserInfo(@Field("user") String userName, Callback<Response> cb); 

This is for sending json and basic auth.

  final String basic = "Basic " + Base64.encodeToString(credentials.getBytes(), Base64.NO_WRAP); RestAdapter.Builder builder = new RestAdapter.Builder() .setEndpoint("http://api") .setClient(new OkClient(new OkHttpClient())) .setLogLevel(RestAdapter.LogLevel.FULL); builder.setRequestInterceptor(new RequestInterceptor() { @Override public void intercept(RequestFacade request) { request.addHeader("Authorization", basic); // request.addHeader("Accept", "application/vnd.api+json"); } }); RestAdapter restAdapter = builder.build(); TestId service = restAdapter.create(TestId.class); service.getUserInfo(resultJsonStart.toString(), new Callback<Response>() { public void success(Response arg0, retrofit.client.Response arg1) { stringFromResponse(arg1); System.out.println(arg1.toString()); } public void failure(RetrofitError arg0) { System.out.println(arg0.toString()); } });