Android system app programming

Как начать программировать под Android? Пошаговый план

В этой статье мы рассмотрим, как начать программировать под Android. Пошаговый план с ссылками на ресурсы, курсы и книги и типичные вопросы, которые задают на собеседованиях на позицию junior Android-разработчика. Ну а если вы хотите быстро за 12 занятий вникнуть в азы Android — то приглашаю на практический онлайн-интенсив где вы с наставником разработаете собственный проект.

Итак, вы решили начать программировать под операционную систему Android. Для начала, вам нужно изучить язык программирования. В мире Android на момент написания статьи (март 2020) года используются как Java, так и Kotlin, однако второй официально рекомендован компанией Google и набирает всё большую популярность, так что, если вы не знаете ни одного языка программирования — то можете изучать Kotlin, если же вы уже знаете какой-либо объектно-ориентированный язык программирования, то изучить Java или Kotlin для вас не составит труда. На рынке тренд идет в сторону Kotlin.

Изучаем язык

Kotlin

Чтобы освоить Kotlin, вам могут пригодиться, следующие ресурсы:

• Try Kotlin — набор примеров и заданий по Kotlin cразу с консолью, в которой можно ввести код и проверить
• Kotlin Bootcamp for Programmers — туториал от Google
• Android Kotlin Fundamentals Course — набор мини-курсов для быстрого старта в Android — разработке
• Книга «Kotlin. Программирование для профессионалов» — Книга Джоша Скина и Дэвида Гринхола основана на популярном курсе Kotlin Essentials от Big Nerd Ranch. Яркие и полезные примеры, четкие объяснения ключевых концепций и основополагающих API не только знакомят с языком Kotlin, но и учат эффективно использовать его возможности
• Kotlin Bootcamp for Programmers — хороший видеокурс, объясняющий основы программирования на Kotlin

Чтобы освоить Java, вам могут пригодиться, следующие ресурсы:

• Изучаем Java Сьерра Кэти, Бэйтс Берт — эта книга не только научит вас теории языка Java и объектно-ориентированного программирования, она сделает вас программистом. В ее основу положен уникальный метод обучения на практике. В отличие от классических учебников информация дается не в текстовом, а в визуальном представлении.
• Become a Java Developer — курс от Udacity, который поможет вам изучить Java
• Джошуа Блох: Java. Эффективное программирование — эта книга является классикой для Java-программистов. Для новичков может быть несколько сложновата, но постарайтесь прочитать ее хотя бы половину и вернитесь к ней через годик, все сразу станет на свои места. Кстати, многие вопросы на собеседовании по Java взяты именно отсюда, так что не ленитесь, почитайте.
• Java. Библиотека профессионала. Том 1. Основы | Хорстманн Кей С. — Эта книга давно уже признана авторитетным, исчерпывающим руководством и практическим справочным пособием для опытных программистов, стремящихся писать на Java надежный код для реальных приложений. Быстро освоить основной синтаксис Java, опираясь на имеющийся опыт и знания в программировании.

Изучаем Android SDK

Как только вы освоили базовый синтаксис и поняли базовые концепции, переходите к изучению Android SDK, параллельно читая перечисленные выше книги. Изучение Android SDK вы можете начать с таких ресурсов как:

• Android Kotlin Fundamentals — набор туториалов для начинающих Android-разработчиков от Google на языке программирования Kotlin. Из курса вы узнаете об основных компонентах Android SDK, таких как Activity, Intent, BroadcastReceiver и других.
• Become an Android Developer — курс на Udacity, где за 6 месяцев вам расскажут от том как разрабатывать мобильные приложения под Android
• Школа мобильной разработки — набор лекций об устройстве Android от Яндекс. Часть материала немного устарела, но даже сейчас будет очень полезна как начинающим, так и уже более-менее опытным разработчикам.
• Android Programming: The Big Nerd Ranch Guide — достаточно понятная книга для новичков, чтобы понять программирование под Android OS
• The Busy Coder’s Guide to Android Development — книга, которая уже, наверное стала классикой для Android — программистов, один из самых полных источников знаний по Android OS

Это далеко не полный список, материалов огромное количество, но изучив вышеперечисленные ресурсы, вам с запасом хватит знаний для программирования под Android. Главное — не забывайте ежедневно практиковаться, общаться с наставником или ментором чтобы быстрее понимать свои ошибки и учиться на них.

Изучаем популярные библиотеки

Итак, вы неплохо знаете синтаксис языка, понимаете ООП, умеете применять наследование там где оно нужно и ваши приложения более-менее работают. Возможно, еще без применения архитектуры (MVP/MVVM/VIPER/RIBs) и без навороченных библиотек или фрэймворков. Самое время изучить и их.

В этом разделе я приведу список наиболее популярных библиотек, который используются в большинстве Android — проектов. Изучив их, вы смело сможете претендовать на звание junior или даже middle — разработчика.

Для многопоточного программирования

• RxJava 2 — видеокурс введение в RxJava на Stepic или бесплатный базовый курс по RxJava
• Kotlin Coroutines — набор туториалов и документация по корутинам от Jet Brains
• Основы работы с WorkManager— туториал по работе с WorkManager
• Advanced Coroutines with Kotlin Flow and LiveData — туториал от Google как рабоать с корутинами и LiveData

Библиотеки для Dependency injection

Библиотеки для сетевого взаимодействия

• Retrofit — пошаговый туториал, где вы создадите приложение для поиска фильмов

Библиотеки для обработки изображений

Библиотеки для работы с Json

Библиотеки для хранения данных

• Room — мини-курс, который поможет понять основы Room + LiveData
• Realm

Изучив, материалы из этого списка вы уверенно сможете претендовать на роль джуниор-разработчика, а в следующем посте мы рассмотрим наиболее часто задаваемые вопросы на собеседованиях. А прямо сейчас приглашаю вас на онлайн-интенсив по разработке

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Top programming languages for Android App development in 2020

Do you have any idea how many Android apps are there in the world? As of 2019’s first quarter, there were approximately 2.6 million android apps around the globe. That’s a huge number which leads to stiff competition in the market.

There is no other option other than offering a robust and efficient Android app to survive in this flourishing industry. The selection of the right tech-stack is highly important if you want to get a flawless development of your Android app.

According to the forecast, mobile app downloads will reach 352.9 billion in the first quarter of 2021. Entrepreneurs are leaving no stone unturned to make their apps reach the peak of downloads and attain success.

Are you wondering how will you make this happen? It is not tough if you have the knowledge and developers of the right programming tools. Out of innumerable programming languages and technologies, there are few for every purpose.

For android app development too, there are some specific programming languages that can be used to achieve a supreme level of outcomes. As we all know, the software industry is highly dynamic and there is a constant introduction to new tools.

Here are the top Android programming language in 2020:

Android programming language #1: Java

It is an official programming language for Android app development. Java is the most popular option for this purpose. Most of the apps in the Play Store are developed with this programming tool.

The major reason behind this popularity is that this programming tool is supported by Google. Since its launch in 1995, it is being used for developing a wide array of applications. It is not easy for beginners and requires an experienced developer to handle the development process.

Good Read: From where you can hire Java developers at 60% less cost?

Android programming language #2: Kotlin

Another popular and official Android programming language is Kotlin. Moreover, it is a popular cross-platform programming language. You can say that it is a secondary Android app development language.

It was announced as the official language for Android app development in 2017. A little difference between the two is that Kotlin is simple for beginners in comparison to Java. Hence, it can be considered as an entry into the Android app development.

Android programming language #3: C#

It is an open-source programming language that is often referred to as the most versatile programming tool. C# developers use Xamarin to develop native apps like Android and iOS. This language is also used to develop consoles, web apps, backend systems, and mobile apps.

Earlier C# used .NET framework which restricted it to the Windows platform. Another benefit of using Xamarin as a tool by C# is its simple and clean syntax which makes it highly convenient programming too to write codes.

Android programming language #4: Corona

It is a software development kit that can be used to create Android apps. In order to use it, you will need to code in Lua. It is quite easy and the complete SDK (kit) makes it even easier.

Mostly, it is preferred to develop games but it is not restricted to this. Another advantage of this SDK is that it supports every native library. Hence, allows developers to publish on various platforms.

Android programming language #5: C/C++

It not a highly recommended programming tool for Android app development. You will have to use the native software kit (NDK) to support C/C++ codes for Android Studio. You can utilize libraries that are written in C/C++.

After reading about the top Android programming languages that can be used for native App development, I hope you have chosen the most appropriate tech stack for your next app. Another thing that is highly crucial for a successful native application is the right mobile app development company.

Here is a recommended list of top 5 android app development companies based on the reviews on trusted rating agencies like clutch and Goodfirms as well as the organic ranking on search engines.

#1. PixelCrayons: An award-winning Android app development company

Looking for experienced as well as adroit developers? Then head straight to this company with 14+ years of experience. One and a half-decade of industry experience provides them with an ability to grasp the needs of clients in the first meeting itself.

Their client retention rate of 97% speaks volumes about their efficiency and hard work. The team is well credited for its strict NDA and 100% money-back guarantee. You can avail of their Android app development services which are combined with the latest technologies like AI, VR, AR, blockchain, etc as per the needs of clients.

#2. Appinventiv: Chooses the best ideas and change them into reality

The team strength of Appinventiv is 250+ employees. In its journey of six years, it has expanded exponentially. Their offices are located in India, the USA, UK, and Dubai. Their team comprises of designers, developers, testers and business strategists.

Their solutions are known for their efficiency and top-notch quality as well as results. The Appinventiv team extends its complete support to allow maximum growth to its clients with optimum android development services.

#3. Mutual Mobile: Blurs the difference between the digital and real worlds.

If you are looking for an android app development company that will work according to your goals, then Mutual Mobile is the best option. Their top-notch solutions find credit in every industrial domain from healthcare to tourism.

They are acclaimed by their clientele for bringing the vision into reality; the digital reality. The outcomes delivered by them are almost equal to the expectations of the service takers.

#4. Quytech: Delivered 150+ projects

It has been a decade since the inception of this efficient company in the mobile app development industry. Their team is delivering its solutions to all sizes of companies from startups to enterprise-level organizations.

They provide detailed consultation to their clients before starting with a project. Technologies covered in their services include artificial intelligence, virtual reality, augmented reality, etc. Quytech has found its clients all over the globe throughout its journey.

#5. ValueCoders: A well-known Android app development company

Since its inception in 2004, Valuecodes has expanded its team to 500+ designers, developers, QAs and testers. It has shown exponential growth in android app development market by focusing on clients from all over the globe.

Each of their team members possesses experience in varied domains to which they are delegated. This means that if you want to develop an android app for e-commerce business then Valuecoders will provide you a developer who has years of experience in this domain.

Conclusion:

Selecting any of these tech stacks or companies have the potential to provide you with a successful application. The ideal choice for your project will be the Android app development company which possesses the capabilities to fulfill your project’s requirements.

If you have any suggestions for the amendments in the list of top programming languages for android or top android development companies, then you can write to me in the comment section below. Happy reading and reviewing!

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Developing System Apps using an emulator

Deploying systems apps on your AOSP emulator

Hope you are able to build custom AOSP emulator as described in the below article :

OS Customization for XR Device

XR devices need OS customization to support the enterprise’s needs. Sharing my experience of building a custom android…

Now is the time to deploy applications as system apps to this customized or any existing emulator.

Android Emulator Setup to develop System applications

The Develop → Test → Debug cycle for an android system application is quite longer than the normal app development cycle. This article describes the emulator setup and a few handy scripts to facilitate a faster development cycle.

Step 1 — Setting up the emulator

If you are using Android Studio like me, the AVD manager of the android studio comes with plenty of preconfigured AVD options to create a virtual device. But most of them are targeted for general app development. we really need to pay attention while creating a virtual device for system apps development. You are free to select any device configuration that matches your requirement. But while selecting a system image for the virtual device, we need to select an image which DOES NOT include “Google APIs”. This is because, if you use images with “Google APIs” we will not be able to sign our system applications with the same key as Google API since it is not available to us. Whereas the plain AOSP images without Google APIs, we can obtain the platform keys from AOSP repository and we can use it to sign our system applications. The image highlighted in green is the right one for AOSP Oreo 8.1.

In case if you have an emulator with “Google API” and try to sign your system app with AOSP platform keys, be assured that it will NOT work.

Step 2 — The Applications Manifest

If you are intent to run your app as a system process, then it is important to include android:sharedUserId attribute in the AndroidManifest.xml

Once you add this attribute, please note that this application can only be installed as a system app. If you try to install this as a normal app, it will fail.

Step 3 — Writing to System partition of the emulator

In order to make an app as a system app, it needs to be installed in “/system/app/” folder. The system partition of the emulator is read-only and you may not be able to do an adb push directly. To make the system partition writable, we need to restart the emulator with “-writable-system” flag

Once the emulator is restarted in writable system mode, use the following snippet to sign your app with AOSP keys and deploy it to system

The above snippet will install your app as a system app and once the emulator reboots you can see your app installed as a system app.

To uninstall the app, we simply need to remove the Applications folder from “/system/app/”. A sample snippet is shown below

Step 4 — Confirming System app status

How do we verify whether our application is indeed running as a system application?

There are a couple of ways, one is that if you open the “App Info” of the application, there will not be any provision to “Uninstall” it since it is a system application. But the foolproof way is to add a debug log to print the Process’s uid once the application is running. Add this code snippet in your Activity’s code

If your application is running as a system process, then it would print

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