Make asynchronous calls with Retrofit

- [Instructor] In last week's tip,…I described how to use the open source library Retrofit…to make web service calls.…In recent versions of Android,…you have to make these calls asynchronously.…I solved that challenge last week by creating an AsyncTask…that receives the request, executes the web service call…in the background and then handles the response…in the onPostExecute method,…which is executed in the main thread.…But Retrofit actually has tools you can use…to make the calls asynchronously without an AsyncTask,…an IntentService or any other sort of separate structure.…

Let's start with the web service.…The web service call doesn't change at all.…You still create a Retrofit object that's accessible…from outside the class and then you define your call…using a get or a post annotation.…In this example, I'm using a get request…to retrieve all data items from the JSON feed.…In my current code, I've wrapped the request…inside the web service task, AsyncTask class.…When I call the execute method,…that results in a synchronous call…