Android Networking I: OkHttp, Volley and Gson

A Java Android sample showing how to combine Volley, OkHttp, and Gson in one small networking playground.

The app uses Volley as the request queue and UI-facing request API, swaps in a custom OkHttp-backed HttpStack as the transport layer, and parses JSON responses with reusable Gson request classes.

✨ What It Demonstrates

• A Volley RequestQueue backed by OkHttp3Stack.
• Generic GsonGetRequest<T> and GsonPostRequest<T> implementations.
• Gson parsing for a JSON object and a JSON array.
• A custom Gson deserializer for the sample DummyObject model.
• Request tagging and cancellation from onStop().
• Volley ImageRequest for a single remote bitmap.
• Volley NetworkImageView with a shared ImageLoader.
• An LruBitmapCache sized from the device display.
• Data Binding for simple click handlers and screen bindings.

🖼️ Demo Screens

Screen	What It Shows
JsonObjectActivity	GET a single object and bind title/body text.
JsonArrayActivity	GET an array and render multiple parsed objects.
NetworkImageViewActivity	Load a list of remote images through Volley image loading.
ImageRequestActivity	Load one bitmap through ImageRequest with an error fallback.

⚙️ Tech Stack

• Java
• Android Gradle Plugin 3.0.1
• Gradle 4.5.1
• compile SDK 27, target SDK 27, min SDK 16
• Android Support Library 27.0.2
• Volley 1.0.0
• OkHttp 3.9.1
• Gson 2.8.2
• Data Binding
• RecyclerView and ConstraintLayout

🚀 Run It

This repo is pinned to 2018 Android tooling. For the least friction, use an Android Studio/JDK setup compatible with AGP 3.0.1 and Gradle 4.5.1.

./gradlew :app:assembleLiveDebug
./gradlew :app:installLiveDebug

The sample uses old public demo endpoints and image URLs. If any network call no longer responds, the app still remains useful as a reference for the request, transport, parsing, caching, and cancellation patterns.

🧪 Verification

No automated test suite is included in this historical sample. The practical sanity check is to build the debug app:

./gradlew :app:assembleLiveDebug

📌 Status

This is a historical sample for an old Android networking article series, not a modern networking template. Its value today is as a compact reference for how Volley, OkHttp, and Gson can be wired together in a pre-AndroidX Java app.

📜 License

The original README declared this repository to be MIT licensed. A standalone LICENSE file is not currently present in the repository.