Which library is used for calling RESTAPI from an Android application?

• A. android-async-HTTP
• B. Retrofit
• C. Volley
• D. OkHttp

Answer: (A)

The chosen answer A, android-async-HTTP, is not widely recognized or favored within the Android development community for calling REST APIs. Instead, Retrofit is an established library designed specifically for this purpose. It simplifies the process of making network requests and handling responses, supports various data formats (such as JSON), and integrates seamlessly with other libraries like Gson for serialization.

Volley is another powerful library that provides a robust framework for making network requests and handling image loading, but it comes with a different set of use cases compared to Retrofit. OkHttp is a lower-level HTTP client that can be used as a foundation for other libraries, including Retrofit, and handles the more intricate aspects of HTTP operations.

By understanding how these libraries function and their intended use cases, one can clearly see that Retrofit stands out in terms of convenience and functionality for interacting with REST APIs within Android applications.