Networking, REST APIs, Retrofit, JSON, and Coroutines
Connect Android apps to backend services and understand how modern apps fetch, parse, and display remote data safely.
Inside this chapter
- Why Networking Matters
- Retrofit and API Calls
- JSON Parsing and Models
- Coroutines in Networking
- Error Handling and Loading States
- Real-World Usage Snapshot
Series navigation
Study the chapters in order for the clearest path from Android setup and Kotlin basics to architecture, background work, release engineering, and advanced mobile development practice. Use the navigation at the bottom to move smoothly through the full tutorial series.
Why Networking Matters
Most modern Android apps depend on APIs for authentication, product data, social feeds, messaging, analytics, or remote configuration. Networking is one of the most practical mobile development skills.
Retrofit and API Calls
interface UserApi {
@GET("users")
suspend fun getUsers(): List<User>
}Retrofit is a popular networking library in Android for defining HTTP APIs cleanly and integrating with Kotlin coroutines and JSON converters.
JSON Parsing and Models
API responses are often in JSON. Strong model design helps apps safely convert API payloads into typed objects that the UI and business logic can use cleanly.
Coroutines in Networking
Coroutines help keep asynchronous code readable and structured. They are one of the best features in modern Kotlin-based Android development.
Error Handling and Loading States
- Handle no internet connection
- Handle server errors and timeouts
- Show loading indicators clearly
- Support retry behavior where appropriate
Real-World Usage Snapshot
Mobile apps for banking, commerce, media, social features, logistics, and education all rely heavily on networking. Clean remote-data handling is one of the most important production Android skills.