I read some examples which are posting jsons to the server.
some one says :
OkHttp is an implementation of the HttpUrlConnection interface p
compile 'com.squareup.okhttp3:okhttp:3.7.0'
OkHttpClient client = new OkHttpClient(); MediaType MIMEType= MediaType.parse("application/json; charset=utf-8"); RequestBody requestBody = RequestBody.create (MIMEType,"{}"); Request request = new Request.Builder().url(url).post(requestBody).build(); Response response = client.newCall(request).execute();