We recently worked on a project where the API wrapped all responses into an envelope. For example, when the app requested the user info, it always got a wrapped response: { "serverInfo": { "apiVersion": "0.0.1a" }, "statusCode": 200, "payload": { "username": "Norman", "id": 42 } } The payload was the actual interesting information. Previously, …

In the Retrofit getting started tutorial you've learned how to create an Android app that connects to the public GitHub API. In following tutorials you've learned how to use OAuth to make requests as an authorized GitHub user. Finally, you've learned how to create new objects. In this tutorial you'll …

Welcome to this tutorial with a very abstract title! OkHttp interceptors are quite great in making Retrofit even better by customizing requests (or responses) in a central place. We've used OkHttp interceptors a lot in previous tutorials (Manage Request Headers, OAuth, and many more). A downside of the interceptors is …

When implementing network requests on mobile devices a lot of things can go wrong: no network connection or the server responds with an error. In either case you need to make sure you deal with the error and, if necessary, inform the user about the issue. In the tutorial on …

In most cases, your app will send and receive all server data in the same data format. For example, if you interact with the GitHub API, you'll send and receive JSON. Nevertheless, Retrofit is quite flexible in its design and allows support for multiple data formats at the same time, …

One of Retrofit's best features is the support of many data formats. It doesn't matter if the server expects and sends XML, JSON or protocol buffer as data format. Once you've configured an appropriate converter, any data format works flawlessly. However, what do you do if your app needs to …

When we introduced our API error handler we threw all possible non-success responses from the server in one bucket and handled them the same way. But this might not be the best idea. For example, a server response with status code 404 indicates that the resource we're trying to access …

Some APIs return an empty response body to signal the client that there is no object. Retrofit's converters can trip over that, because it can be an invalid representation in their respective data format. For example, an empty object needs to be {} in JSON. In this tutorial you'll learn how …