从 Java 迁移到 Kotlin，这 14 个 App 是怎么想的？

在 2017 谷歌 I/O 开发者大会上，谷歌宣布 Kotlin 语言和 Java 一样，成为 Android 应用开发的一级语言。从此，这门由位于俄罗斯的 JetBrain 团队开发的语言开始广受瞩目。

Kotlin 有着简洁的语法，同时可以与 Java 很方便地进行互操作。另外，基于 Android Studio 对它的良好支持，不难看出 Google 在向外界证明 Kotlin 在 Android 应用程序开发中的地位。2018 年的 Google I / O 继续安排了 Kotlin 专题，也更加验证了这一点。

从 2017 到现在，无论是开发者还是企业，对 Kotlin 的需求都呈指数增长。根据一份对全球范围的移动应用开发者的调查显示，有百分之二十在 Google I / O 2017 大会之前使用 Java 构建的应用程序后续都迁移到了 Kotlin，这一趋势也引发了市场上对 Kotlin 开发者的需求激增。

本文将会为你介绍 14 个从 Java 迁移到 Kotlin 的 App，但在此之前，我们先来看下选择 Kotlin 可以为你带来哪些优势。

Kotlin 的优势

1. 提升代码的可维护性，节省开发时间

Kotlin 比 Java 更简洁，大大减少了代码的数量。这意味着它可以用更少的代码行解决更多问题，工程师也可以更高效地阅读和修改代码。

相比 Java，Kotlin 提供了许多使语言更简洁的特性，比如智能转换、数据类、属性和类型接口。

2. 降低应用程序的崩溃率

Kotlin 的代码比 Java 更安全，因为它在设计上避免了常见的编程错误，从而减少了应用程序崩溃和系统故障。此外，由于 Kotlin 是快速失败机制，因此可以立即报告任何可能导致失败的问题。而且，Kotlin 附带的快速失败编译器会搜索错误并阻止它们再次出现。

3. 大大缩小代码量，让项目更易维护

与 Java 相比，使用 Kotlin 开发需要的代码行数量要少得多，这不仅可以节省开发时间，还可以节省应用程序维护精力。

除了这些商业利益之外，Kotlin 还有许多优势。

从 Java 到 Kotlin 的好处

看到 Kotlin 语言的优势，已经有不少 App 都在从 Java 往 Koltin 迁移，这些优势具体来说有以下几点：

1. 已被大范围采用

虽然 Kotlin 是一门新语言，但是已经有不少公司已经从 Java 迁移到 Kotlin。

2. 简洁

相比 Java，Kotlin 非常简洁，减少了一些本来就没有那么多必要的模板代码，极大地提高了开发效率。因此，也大大降低了出错的概率，使生成的代码更安全可靠。

3. 更好的用户体验

随着出 bug 概率和 App 的崩溃率大大降低，产品的稳定性会有很大提升。因此，用户在使用产品时会更加流畅，用户体验也就更好。

4. 快速失败机制

这一次，谷歌为 Android 应用程序的编程语言带来了新的变化，他们让 Kotlin 有快速失败机制。快速失败的系统会立即报告任何有可能导致失败的编码问题。当问题出现时，快速失败机制会立即响应。

5. 让开发人员更轻松

Kotlin 使 Android 应用开发对开发人员而言变得轻而易举。除了易于使用，还有强大的 Android 应用开发者社区的支持。

所有这些优势累积起来，使 Kotlin 成为“什么是 Android 应用程序的编程语言”的最佳答案。

Kotlin 的采用率非常高，以至于没准你常使用的某个 Android 应用就是用 Kotlin 搭建的。

14 个使用 Kotlin 的 App

这 14 个 App，都是用 Kotlin 开发的。

1. Pinterest

Pinterest 是美国的一个图片分享类社交网站，Pinterest（Pin+Interest），意为把自己感兴趣的东西用图钉钉在钉板（PinBoard）上，用户可以按主题添加和管理自己的图片收藏，并与好友分享。Pinterest 是著名的使用 Kotlin 进行开发的 App 之一。该品牌正式从 Java 迁至 Kotlin，并在 Droidcon NYC 2016 上展示了此举的好处。

2. Gradle

Gradle 是一个基于 Apache Ant 和 Apache Maven 概念的项目自动化构建工具。最近，Gradle 将 Kotlin 作为编写构建脚本的语言。Kotlin 同时支持 IDEA 和 Eclipse，同时为 Gradle 用户提供了从代码重构到自动补全等一系列完整的 IDE 支持。

3.Evernote（印象笔记）

印象笔记是一款多功能笔记类应用笔记，在其 Android 客户端中集成了 Kotlin。

4.Corda

Corda 是一个开源区块链项目，它帮助区块链开发人员创建可互操作的区块链网络，完全基于 Kotlin 开发。

5. Coursera

这个全球知名的在线课程 App 也部分基于 Kotlin。Coursera 与全球一流大学和机构合作提供在线课程，数百万的活跃用户在该平台学习不同主题的课程。

6.Uber（优步）

优步使用 Kotlin 进行内部工具处理，例如注解处理器和 gradle 插件。

7.Pivotal 公司的 Spring 框架

大多数人可能不熟悉 Pivotal 公司。但如果你是一个开发者，在 Java 后台开发使用最多的一个框架——Spring，就是由 Pivotal 开发的。Spring 框架使用 Kotlin 为开发者提供了更简洁的 API。

8. Atlassian | Trello

Trello 是一个方便的团队协作工具，2017 年被 Atlassian 收购。虽然 Trello 不打算对旧代码库进行转换，但他们的新代码使用了 Kotlin。Java 和 Kotlin 之间有很好的互操作性，因此 Trello 能够两者兼容。

9. Basecamp 3

Basecamp 是 37signals 公司旗下的一款非常流行的基于云服务的项目管理软件。以简单易用和颠覆性的创新而出名。自从他们从 Java 转向 Kotlin 以来，Basecamp 的开发人员已经认识到代码质量和开发速度的巨大差异。

10. Twitter 的 Twidere

Twidere 是一款功能齐全的开源 Twitter 客户端，可以自定义主题、管理无限制帐户和过滤不良推文。Twidere 应用程序用 Kotlin 开发，由于其流畅的性能，已经获得了 100,000+ 的装机量。

11. Shadowsocks

安全的跨平台 socks5 代理可以帮助用户安全私密地上网。这个在 Google Play 商店下载量超过 1,000,000 的 App 完全基于 Kotlin 开发。

12.Simple Calendar

Simple Calendar 是一款完全开源的无广告日历 App，也是完全基于 Kotlin 开发。界面非常美观，功能也很强大。

13. Kickstarter

Kickstarter 是世界最大的专为创意方案筹资的众筹平台，可以帮助音乐家，艺术家，设计师，电影制作人和其他创意人员筹集将他们的想法转变为现实所需的资源和支持。该应用也由 Kotlin 开发。

14.Square

自从 Square 的 Android 应用使用了 Kotlin，这个支付平台就成为了 Kotlin 的布道者。

Know Why These 15 Famous Apps Migrated from Java to Kotlin

Google in its I/O 2017 Developer Conference announced that it will now officially base its Android App Development process on Kotlin – the language developed by the JetBrains team of programmers based in Russia.

The features that Kotlin comes powered with –  Interoperability with Java, Conciseness, and Android Studio support – were enough for Google to validate the language’s position in the world on Android Application Development Industry, something that the tech giant continued to highlight in I/O 2018  by scheduling sessions on the Android new programming language .  

Just days after the announcement of Kotlin becoming the official language of Android at the I/O 2017 developer conference, the programming language found itself in the  list of top programming languages that will define 2018 .

Between 2017 and mid of 2018 (the present time) the language has seen an exponential rise in demand from both developers and businesses. The  realm report  that surveys mobile app developers globally also found that 20% of the Android apps that were built on Java before the Google I/O 2017 conference, were then migrated on Kotlin. A movement that has brought in a surge in demand for Kotlin developers.

In the October of 2017, we covered Kotlin in depth in one of our blogs,  head on there to read the article where we dissected Kotlin and highlighted ways it is better than most of the other programming languages .

Taking what was started by Kotlin in 2017 forward, the Android industry in the present day is staring at the mass adoption of the language, with the portfolio comprising of a number of hot-shot brand names.

In this article, we will be looking at 14 such brands that have adopted Kotlin by migrating from Java to give you an idea of why it’s time for you to follow the lead to.

But before that, here are the business benefits that you can take advantage of by choosing Kotlin for your next Android App project.

What are the Business Benefits of Choosing Kotlin – The Official Programming Language for Android Apps

1. Improved Code Maintainability Meaning Faster Development Time

Kotlin is a lot more Concise than Java, meaning it can solve more problems with fewer lines of code. It means that the engineers can read and change the code much efficiently.

There are a number of features that come associated with Kotlin, which make the language more concise – Smart Casts, Data Classes, Properties, and Type Interface.

2.  Lower Instances of Application Crashes

Kotlin code is a lot safer than the Java code as it averts the common programming mistakes in design, which results in lesser application crashes and system failures. Also, since Kotlin works on a fail-fast system, any issue that can lead to failure are reported instantly.

The fail-fast compiler that Kotlin comes with searches for bugs and prevent them from coming again.

3. Shrinked Codebase Leads to Easy App Maintainability

Android app development done using Kotlin calls for a lot less number of code lines as compared to Java, which ultimately not just saves the development time but also the app maintenance time and efforts.

Apart from these Business Benefits, there are a number of advantages that come associated with Android Kotlin.

Seeing these myriads of benefits that Kotlin Android App bring with themselves, the Android mobile app development industry has now eventually started moving to the adoption of Kotlin Programming Language. A move that has been bringing about a transition from Java to Kotlin.

Kotlin Developers that have made the switch from Java to Kotlin have realized a series of benefits that have also become the reasons why it is time for the Android App Development Industry to start making the switch.

Why is the Android App Development Industry Moving from Java to Android’s New Programming Language?

This is Why –

1. Mass Adoption

Even though Kotlin – the new language for Android Apps is a new entrant in the industry, there are a number of companies – established and new alike – that have migrated from Java to Kotlin to take advantage of the benefits that the language comes with.

*More on That Later.

2. Concise

Kotlin Android Apps are very concise. The resulting code of a Kotlin programming language reduces the total number of boilerplate codes, which enhances productivity to a great extent. Also, there is a lot less room of error, while the resulting code is a lot safer and reliable.

3. Better User Experience

Kotlin programming language makes your app a lot more stable by removing the bugs and reducing the instances of app crashes. And when your app is launched with these issue missing, the user experience only enhances.

4. Designed to Fail-Fast

This time around, Google has brought changes in its new programming language for Android Apps. They have made Kotlin fail-fast.

A  fail-fast system  immediately reports any issue in coding that is most likely going to lead to failure. When a problem emerges, the fail-fast system fails immediately, making it impossible for the Kotlin developers to move ahead with the mobile app development process.

5. Kotlin for Android is a Developer’s Retreat

Kotlin programming language makes Android App Development process a breeze for the developers. The language is both – easy to use and comes with the support of a strong community of Android app developers.  

All these benefits cumulatively have resulted in the making Kotlin the answer to ‘What programming language are Android Apps Written In’.

The adoption rate of Kotlin is so much so that the probability that one of the Android apps that you are using are made using Kotlin is extremely high.

Here are the 14 Android Apps That are Made Using Kotlin for Android –

1. Pinterest

The popular photo-sharing app, Pinterest is one of the biggest names that have used Kotlin for Android App Development. The brand officially moved from Java to Kotlin and showcased the benefits of the move at Droidcon NYC 2016.

2. Postmates

The on-demand food delivery app also recently shifted to Kotlin for its Android version of the mobile app. The reason for this switch from Java to Kotlin can be attributed to the fact that the language is famous for supporting high scalability and is known to be engineered around a fail-fast mechanism.

3. Evernote

The note-taking and task organization app also have integrated Kotlin in their Android client.

4. Corda

Corda, the open source blockchain project that helps Blockchain developers  create interoperable blockchain networks is also based entirely on Kotlin.

5. Coursera

The world-renowned online courses app is partially based on Kotlin as well. The app has millions of active users who use the platform to take courses on a range of different topics.

6. Uber

The global leader in on-demand commutation market, Uber uses Kotlin for Internal Tooling processes such as annotation processors and Gradle plugins.

7. Spring by Pivotal

The Spring Framework offers a comprehensive configuration and programming model for the development of modern-day Java-based enterprise apps – on every sort of deployment platform. The framework uses Kotlin to provide more concise APIs

8. Atlassian | Trello

While Trello is not planning to do a full code conversion of the old codebase, the new code that they are using is made using Kotlin. Since there is great interoperability between Java and Kotlin, the brand is able to work with both.

9. Basecamp 3

Basecamp developers have admitted witnessing a huge difference in code quality and speed ever since they made the switch from Java to Kotlin.  

10. Twidere for Twitter

Twidere is a full feature open source Twitter client app that customizes the theme, manages the unlimited accounts, and filters unwanted tweets. Developed in Kotlin, the app has been able to bag 100,000+ install rate because of its smooth performance.

11. Shadowsocks

The secure cross-platform socks5 proxy helps user surf the internet securely and privately. The app with 1,000,000+ downloads on the Play Store is made entirely on Kotlin.

12. Simple Calendar

The ad-free fully open source calendar app is also made entirely on Kotlin.

13. Kickstarter

The app helps musicians, artists, designers, filmmakers, and other creatives find all the resources and the support that they would need to convert their ideas into a reality. With thousands of active users, the app is powered by Kotlin.

14. Square

Ever since Kotlin was approved by Square for their Android Applications, the payment platform has become the evangelists of Kotlin for Android.

15. Gradle

Gradle is the custom build tool that is used for developing the android packages (apk files) by providing the custom build logic and managing dependencies. And recently, Gradle introduced Kotlin as the language for writing the build scripts in. Since Kotlin gives support for both IDEA and Eclipse, Android’s new programming language gives the Gradle users full IDE support for refactoring to autocompletion and everything in between.

Get your app’s name added in the list,  get in touch with our team of Android Kotlin experts , today.

Now that we have looked at the benefits that come attached with developing an app through Kotlin and how their a number of hot-shot apps that are benefitting from this association, we have come to the end of the article where we will talk about the pointers that you should look out for BEFORE you plan to join the league of those famous apps by migrating to Kotlin.

What Do You Need to Know Before Migrating Your Java App to Kotlin?

A. Is your team ready to make the switch?

Shifting the development method from one programming language to another comes with a learnability curve. So, before you make the switch, ensure that your team is willing to support this journey of yours.

B.  Is your app architecture made of loosely coupled components?

Once you have ensured that both the pointers are in place, you no more have a reason to not make the switch from Java to Kotlin, like the app industry’s top leaders did.