Analysis of JRebel 2020 Java Technology Report: Popular Languages, Frameworks, Servers, IDEs, Databases, Build Tools, and Container Platforms

JRebel’s 2020 Java ecosystem report surveyed developers on the technologies they use, covering programming languages, application architectures, servers, runtimes, frameworks, IDEs, JRE/JDK versions, databases, deployment models, build tools, and virtualization tools.

Java version adoption: 58% of respondents primarily use Java 8, followed by Java 11 at 23%; 7% still use Java 7 or earlier, and only 6% have moved to Java 12 or newer. Kotlin and JavaScript have the lowest usage rates at 3% and 2% respectively.

Application servers: Tomcat remains the most popular, used by 61% of developers, which is five times the share of the next server, Jetty.

Frameworks: Spring Boot is the dominant Java framework with 82% adoption, driven by the rise of micro‑services. Overall, 86% use Spring, 51% use persistence frameworks such as Hibernate, OpenJPA or EclipseLink, 27% employ server‑side rendering technologies (JSP, JSF, Thymeleaf, etc.), 26% use JAX‑RS/JAX‑WS implementations, and 11% have adopted reactive frameworks like Vert.x.

Configuration style: Annotation‑based configuration slightly leads XML, with 67.92% using annotations versus 67.17% using XML.

IDE preferences: IntelliJ IDEA is the leading IDE at 82% usage, while Eclipse holds the second place with 24%.

Databases: PostgreSQL is the most popular (47%), followed closely by Oracle (42%); MySQL is used by 28% and MongoDB by 12% of respondents.

Build tools: Gradle is used by 47% of developers, slightly surpassing Maven’s 44% share.

Virtualization tools: Docker dominates container usage at 74%, with Kubernetes as the second‑most popular tool at 35%, reflecting its rapid growth.

Impact of micro‑services: The survey shows a strong influence of micro‑service architectures on technology choices, and the trend is expected to continue shaping future selections.