[DZone Research] So Many Versions, So Much Kotlin

This article is part of the Key Research Findings from the 2018 DZone Guide to Java: Features, Improvements, and Updates.

Introduction

For this year's DZone Guide to Java, we surveyed 507 software professionals on various topics related to the Java language and its use in programming. In this article, we focus in on the data from that survey to discuss how developers are reacting to and adopting the various version of Java out there, as well as the upward trend of Kotlin in the industry. 

Java Versions

Since DZone’s 2017 Guide to Java Development and Evolution was released, Java has continued to… evolve. Between the publication of that guide and the article you’re reading now, Java 9 and Java 10 have been released, public updates for Java 9 have ended, Java SE 11 was officially released, and public updates to Java 10 have ended. By the time DZone’s next Java Guide is released, it's likely that public updates of commercial-use Java 8 will have ended (expected around December of 2018/January 2019).

The change in Java’s release cadence likely has a direct impact on the responses we saw in this year’s survey regarding Java release adoption. Survey responses were collected roughly one month after Java 10 was released, and about 7 months after Java 9’s release. 30% of respondents this year said they are using Java 9 or above, and these respondents are almost exclusively using Java 9+ in new (rather than existing) apps – only 6% of respondents say they are using Java 9 or above in existing applications. Java 8, meanwhile, remains the predominant version of Java, with 92% of respondents saying they use Java 8 in some way. While respondents who said they use Java 8 in new apps fell from last year’s results (89% in 2017 to 77% in 2018) as the adoption of new Java versions takes off, there was an increase in respondents who said they use Java 8 for existing apps, from 49% to 61%. This is on par with the number of respondents who said they were using Java 8 for new apps in DZone’s first Java survey, which was released about a year and a half after Java 8’s release in 2014. Only 11% of respondents said they are using Java 7 or below for new apps, down from 19% last year.

Kotlin, Kotlin, Kotlin!

Overall, JVM language adoption has not seen a lot of growth over the last few years. The two (non-Java) JVM giants – Groovy and Scala – saw fluctuations in survey responses from 45% (2016) to 43% (2017) to 45% (2018) for Groovy, and 41% (2016) to 38% (2017 and 2018) for Scala, these shifts being well within the survey’s margin of error, showing no significant change in the adoption of these technologies. Kotlin, on the other hand, has seen extraordinary adoption since 2016. 2016’s Java survey saw 7% of respondents using the JVM-based language; this grew to 16% in 2017 and now to 34% in 2018. This means Kotlin adoption among our respondents has more than doubled each year for the past two years. Of course, it’s impossible to directly correlate adoption rates of these technologies, considering Groovy and Scala were first released in 2004, giving plenty of time for extra hype to fade, while Kotlin was first released in 2011 and open-sourced in 2012. But Kotlin has certainly surpassed other JVM-based languages like Ceylon and Clojure to be among the top JVM languages out there; and with Kotlin’s appeal for Android development, it’s likely that its popularity will continue to grow.

Conclusion

Do these findings hold up outside of the DZone community? Well, there's not a lot of survey data out there about the varying Java versions, but, if we look at the Stack Overflow 2018 Community Survey, we see a growing Kotlin following there was well. In fact, Stack Overflow users named Kotlin the second most loved language of the year (75%), finishing only behind Rust. This was a huge increase in the love shown to Kotlin, which didn't even make the list in the Stack Overflow's 2017 report. 

This article is part of the Key Research Findings from the 2018 DZone Guide to Java: Features, Improvements, and Updates.