New Relic released its fourth annual State of the Java Ecosystem report. The report is based on data from hundreds of thousands of applications and provides insights into the current state of the Java ecosystem, including how developers are using it and the most-used Java versions in production. 

Despite being introduced nearly 20 years ago, Java continues to be one of the most popular programming languages among developers. Java owes its popularity to its scalability and portability, allowing users to run on any device with a Java virtual machine (JVM). Java has strong community support with Oracle supporting a forum for questions and a tutorial website. Oracle releases new Java versions every six months, and new Java long-term-support (LTS) versions every two years. The new LTS versions include updates to help improve stability, security, and performance, which developers often cite as one of the most important factors for upgrading Java versions.

Key findings from the report include: 

• Java 21 sees higher adoption than Java 17: Following the release of Java 21 in September 2023, the report found that the adoption rate for the latest Java LTS version was 287% higher in the first six months after release than its previous LTS counterpart, Java 17.
• Java 17 overtakes Java 11 as the most-used LTS version: The Java 17 growth rate exploded to a nearly 300% year-over-year (YoY) increase, with over 35% of applications using Java 17 in production this year compared to 9% in 2023. To put this growth into perspective, it took years for Java 11 to reach a similar growth rate.
• Eclipse Adoptium steadily gains traction as one of the most popular JDK vendors: While Amazon remains a widely popular Java Developer Kit (JDK) vendor, its usage decreased 43% YoY in 2024, down to 18% this year compared to 31% in 2023. On the other hand, the adoption of community-managed Eclipse Adoptium rose 50% YoY from 12% to 18%, revealing developers' increasing preference for JDKs that are updated more frequently.
• Log4j and Bouncy Castle are the most popular logging framework and encryption library: New Relic data revealed that Log4j is the most popular logging framework, with 76% of Java applications that report to New Relic using it. Similarly, Bouncy Castle topped the list as the most popular library for encryption, with 17% of Java applications using it.
• Developers' frequently asked Java-related questions: The most common types of Java-related questions and requests asked by developers using the New Relic AI generative AI observability assistant include how-to type questions (34%), followed by querying for a specific metric (21%), and troubleshooting (14%).