JNTU MCA 2021 MOBILE APPLICATION DEVELOPMENT Previous Question Paper (July/August - 2021 - R17)

The Android stack is a layered software architecture designed to provide a comprehensive environment for mobile applications. It consists of five primary layers:

1. Linux Kernel: The foundation of the stack, providing essential hardware abstraction, memory management, security, and power management. It also handles drivers for display, camera, and Wi-Fi.
2. Hardware Abstraction Layer (HAL): Provides standard interfaces that expose device hardware capabilities to the higher-level Java API framework, allowing the framework to remain agnostic of specific hardware implementations.
3. Android Runtime (ART) and Native Libraries: ART executes apps and provides core features like garbage collection. Native libraries include C/C++ libraries such as SQLite for database management, OpenGL for graphics, and WebKit for browser functionality.
4. Java API Framework: Exposes the entire feature set of the Android OS to developers. It includes managers for views, resources, notifications, and content providers.
5. System Apps: The top layer containing pre-installed applications like the home screen, contacts, and browser, which run on top of the framework.

The SDK Manager is a tool within Android Studio that allows developers to download and manage various versions of the Android SDK platforms, build tools, and platform tools. It ensures that the development environment has the necessary libraries, APIs, and system images required to target specific Android versions, enabling compatibility across a wide range of devices.

An Android Virtual Device (AVD) is an emulator configuration that simulates a physical Android device on a computer. It allows developers to test applications without needing a physical handset. Key features include:

• Customization of hardware profiles (screen size, RAM, storage).
• Ability to select specific Android API levels and system images.
• Simulation of device features like GPS, sensors, and network conditions.
• Rapid deployment and debugging of applications during the development cycle.