JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD MCA 2022 MOBILE APPLICATION DEVELOPMENT Previous Question Paper (September/October - 2022 - R20)

The Android operating system is a powerful, open-source platform based on the Linux kernel. Its key features include:

• Open Source: Android is built on the Android Open Source Project (AOSP), allowing developers to customize and modify the OS for various hardware.
• Application Framework: It provides a robust framework that simplifies the reuse of system components, such as views, content providers, and resource managers.
• Dalvik/ART Runtime: Android uses the Android Runtime (ART), which employs ahead-of-time (AOT) compilation to improve application performance and battery efficiency compared to the older Dalvik virtual machine.
• Integrated Browser: Based on the open-source WebKit engine, it provides a seamless web browsing experience.
• Optimized Graphics: It includes custom 2D graphics libraries and 3D graphics based on the OpenGL ES specification.
• Media Support: Android supports a wide range of audio, video, and image formats, including MPEG4, H.264, MP3, AAC, JPEG, and PNG.
• Multi-touch and Connectivity: It natively supports multi-touch input and a broad array of connectivity technologies, including GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, and NFC.
• SQLite: A lightweight, relational database is integrated into the OS for efficient data storage and management.

The Android manifest file (AndroidManifest.xml) is essential for every application, as it provides the Android system with the information required to run the app. Key attributes and elements include:

• package: Defines the unique namespace for the application, typically the Java package name.
• android:versionCode: An integer used to track the version of the application internally; it is not displayed to users.
• android:versionName: A string value representing the user-visible version number of the application.
• android:minSdkVersion: Specifies the minimum API level required for the application to run.
• android:targetSdkVersion: Indicates the API level the application is designed to run on, allowing the system to enable compatibility behaviors.
• android:icon and android:label: Define the application's launcher icon and the display name shown to the user.
• <uses-permission>: Declares the permissions the application requires to access sensitive data or system features (e.g., camera, internet).
• <activity>, <service>, <receiver>, <provider>: These elements declare the application components and their attributes, such as intent filters, which define how the system can launch these components.