10 steps and you are an Android developer!
What language to choose, how to learn how to write applications and what to look for when developing programs for mobile devices.
Android developer is the profession of the future. The main trends in the development of mobile technologies in the coming years will be associated with the following areas:
Augmented and virtual reality. AR and VR are already being used in mobile games and when visiting interactive museums. Sharing with geolocation services gives a special chic. Mobile devices are the most affordable option to take advantage of these technologies.
Machine learning (ML) algorithms.
We don’t even notice how many different ML solutions we already use in our smartphones: text recognition, face detection, barcode reading, landmark recognition, audio-to-speech conversion, chatbot consultations, etc. All these technologies make our lives easier. As device performance increases and cloud computing becomes more accessible, more resource-intensive algorithms will come into fashion.
The share of mobile traffic is growing, more and more users using mobile devices gain access to various applications and resources. The information boom requires productive capacity, and cloud computing is an efficient way to meet these needs.
Electronic payments. It is becoming easier and easier to buy goods using smartphones: both with the help of NFC and online. And new technologies such as blockchain provide better payment security.
A significant part of our life is spent with a smartphone in hand, a lot of important things are stored here. Mobile devices are an attractive target for hacker attacks. Most of the vulnerabilities are the result of insufficient development of the protection concept. Improving the quality of protection will stimulate market development.
But what skills do you need to become a successful Android developer? Where to begin?
1. Select a programming language
The two main programming languages for developing Android applications are Java and Kotlin. In fact, if you are serious about developing, then you cannot do without both languages. However, it was announced at the Google I / O 2019 conference that Kotlin is the preferred and official language for Android. Using Kotlin reduces the number of errors in the code, the language can be easily integrated into existing applications. To master this language, you can use our selection of resources for learning Kotlin.
2. Choose an interactive environment for Android development
Choosing a development environment is a matter of taste. However, the first step is to use Android Studio. The latest version of IDE 4.0 from May 2020 is available for download on the official Android website. We wrote about the last release in our publication.
3. Examine the manifest and components of the Android application
When you draft your first project in the design environment, the framework will automatically create an AndroidManifest.xml manifest file in the Android project folder.
The manifest file contains a unique identifier for the application and describes the components of the application. Go through this list of components, you will understand what you need to learn:
Activity – application screen with user interface. Particular attention should be paid to studying the Activity Lifecycle.
Services are components that run in the background. For example, services can process network transactions, play music, perform file I / O, or interact with a content provider.
Content providers. Situations often arise when you need to access information from another application. Content providers manage data: audio, video, images and personal contact information (contacts, call list). This is the only way for Android apps to share data.
The Broadcast receiver is a component that responds to messages from the Android system and other applications: messages about low battery power, unavailability of a mobile network, and the appearance of Wi-Fi networks in range.
Intents are objects that connect individual components (Activity, Service and Broadcast receiver) while the application is running.
4. Learn the basic elements of the Android application user interface
The main elements of the application user interface are:
UI Layouts – layouts of application screens;
UI Components – input / output fields, buttons, toolbars, display and multimedia elements, data display elements, for example, RecyclerView;
App Resources – application resources: strings, fonts, styles, raster and vector graphics, icons and animation;
Fragment is an Activity user interface module. When developing a custom Fragment, special attention should be paid to studying it.
5. Explore Android Data Stores
Learn how to store app and user data on a device: in key-value pairs, a database, or other types of data.
It is also important to learn how to exchange data between applications and devices. It is useful to become familiar with backup services so that users can store information in the cloud, sync it across devices, and restore it when they purchase a new device.
The system provides several options for data storage:
The app-specific storage stores files specific to your application only. Either in dedicated directories on the internal storage or in directories on external storage. If the information is confidential, it is best to store it in internal storage.
Shared storage stores files that an application intends to share with other applications: media, documents, and other files.
Preferences are used to store primitive data in key-value pairs.
Databases are used to store structured data in a private database using the Room library.
6. Learn How Android Build and Gradle Plugin Works
The Android build system collects application resources and source code and packages them into APK files. They can be tested and redistributed. Android Studio uses Gradle, an advanced automation and build management tool. This allows you to define different configuration settings for different projects.
7. Learn to Build Multi-threaded Android Applications
Every Android developer is faced with the need to use streams. When the application starts, it creates a main thread of execution. For the application to remain responsive, it is necessary to avoid using the main thread to perform operations that lead to its blocking: network operations, accessing the database, loading components. Such processes run in separate threads. Android provides many ways to create and manage streams. When using the Kotlin language, you can use Coroutines for these tasks.
8. Learn Methods for Debugging an Android Application
Debugging an application is the process of finding and fixing bugs and other incorrect behavior in your code. To understand what is happening and find the error, we can use debugging to pause the program execution in the place we need and see the contents of objects and variables.
Application debugging is carried out using standard tools provided by the Android Studio development environment.
9. Learn to work with third-party libraries
Not every task can be solved using standard Android tools. For many tasks, their own solutions have already been developed, which are a sin not to use. For image processing and loading, these are Glide and Picasso, for Dependency Injection – Dagger, Koin, Kodein and Hilt, for network interactions – Retrofit, for multi-threaded programming – RxJava. Do not be lazy to also explore Google libraries: Firebase, Google Play Services, Google Maps. Getting familiar with the design of third-party libraries will also teach you how to write better code in your own projects.
10. Explore Android Jetpack – a set of libraries and tools that speed up the work of Android developers
Android Jetpack is a collection of libraries and tools created by the Google team to make Android development easier. Libraries included in Jetpack are divided into four types:
Foundation – Core libraries to help you reduce boilerplate code.
Architecture Components are libraries used to build application architecture.
Behavior – wrapper libraries for functionality provided by the Android SDK. Designed to improve the standard Android API: Permissions, Notifications, CameraX and others.
UI – Components for working with fragments, user interface elements, and animation.