Kotlin Edges Java Among Android Devs

Oracle execs speaking to attendees at last week's JavaOne conference pushed hard on the "Java First" concept. Mark Cavage, Oracle's new VP of product development in the company's Java and Container Native Platform group, used an oft-repeated observation by Redmonk analyst James Governor ("When companies grow up, they turn into Java shops") as a call to arms.

"That tells us ... that people are writing in something first and then rewriting in Java," he said. "We need to change that ... We want the next decade to be Java first and Java always."

Governor was talking about server-side development, of course, and if the results of a recent report are any indication, that's where Oracle should focus its "Java first" efforts. The publishers of the first edition of the Realm Report, released yesterday, found that Android developers are abandoning Java in favor of Kotlin.

The new report was published by Realm, a provider of a popular independent in-app mobile database. The results are based on an analysis of the behavior of more than 100,000 developers using the Realm Database in their applications. The mobile DB is currently installed on more than 3.5 billion iOS and Android applications, including Starbucks, SAP, eBay, Intel and Alibaba. The report is the first of a planned quarterly series, explained Paul Kopacki, Realm's VP of marketing.

"Because of our popularity, we have a unique point of view on what's going on with mobile developers," Kopacki told ADTMag. "When developers are building their apps using Realm, when they do a compile we get a totally anonymized packet from them telling us what parts of Realm they're using, which OSes they're targeting, which languages they're using, and a few other bits of metadata. We look at that data to understand how they're working with us, but there's actually a lot of interesting generalized data in there. And we decided to share our interpretation of some of that data."

The company has been compiling data on mobile application development since August 2015, Kopacki said. This first edition of the Realm Report focused on the most popular programming languages developers use to build mobile applications, and found the following:

  • Java is losing developer mindshare, and fast. The percentage of Android applications built using Java decreased by 6.1 percent, and dropped from 50.7 percent to 46.2 percent of overall apps in the last four months.
  • Kotlin adoption is exploding. The number of applications built using Kotlin has grown by 125 percent. The explosive growth has come since Google officially made Kotlin a first-class language for writing Android apps, announced at Google I/O in May 2017. 20 percent of Kotlin applications built since the conference had previously been built with Java.
  • Kotlin will overtake Java. Based on the data, Realm predicts that Kotlin will overtake Java in December 2018 -- 17 months after Google announced official support at Google I/O. By contrast, it took 14 months for Swift to reach the same milestone versus Objective C for iOS app development.

The Realm Report isn't the only recent industry report to notice a rise in Kotlin's popularity. Redmonk, Tiobe and RebelLabs have acknowledged its impact, especially on Java, which was once the go-to language for Android developers.

The popularity of Kotlin among both Java and Android developers has been growing steadily since JetBrains created and then open sourced the statically typed programming language in 2011. Kotlin targets the JVM, Android, and JavaScript, and also compiles to native code. In May, it began shipping out of the box with Android Studio 3.0.

"Java is a great language, and I'm a big fan," Kopacki said. "But like a lot of things, it's pre-mobile, and it was kind of shoe-horned into the mobile environment. They've done a really good job of it. It made Android the most popular operating system on the planet. But it's hard to work with, and mobile-style developers are painfully aware of that, which is why they are embracing Kotlin."

About the Author

John K. Waters is the editor in chief of a number of sites, with a focus on high-end development, AI and future tech. He's been writing about cutting-edge technologies and culture of Silicon Valley for more than two decades, and he's written more than a dozen books. He also co-scripted the documentary film Silicon Valley: A 100 Year Renaissance, which aired on PBS.  He can be reached at [email protected].