Android sample project that contains different examples of REST API call to the server using Retrofit2 Android Library.
It contains different sample codes on how to implement Retrofit2 Android library to make different HTTP request to the backend server to post or get data from the server. In this sample the Android application is making different RESTful API calls to the server. There is sample of multi-part data request as well in this demo project.
There is also a source code of backend server written using express.js framework based on node.js available in the directory RetrofitDemoBackend.