VMware has released its annual survey of Spring developers, finding high interest in Project Loom (lightweight threads for Java) and enthusiasm for Spring Native, which compiles Java to native executables using GraalVM. Unfashionable technology also hangs on though, with SOAP web services accounting for 30 percent of APIs implemented in Spring, up from 28 percent the year before.

Implementing APIs is a big deal in the Spring world. 86 percent of those surveyed write applications that expose APIs to internal consumers, and 73 percent for external consumers, whereas general business applications are in third place at 72 percent. SOAP web services, based on XML, have for most developers been long superseded by REST APIs and JSON, and the JSON-based OpenAPI (once known as Swagger); but although plain JSON (81 percent) and OpenAPI (61 percent) are well ahead, the fact that 30 percent of Spring developers still work with SOAP shows how sticky it is.

The Spring framework is critical to the Java ecosystem: a recent JetBrains survey found 67 percent of Java coders using Spring Book and 41 percent Spring MVC, far ahead of other options.

The VMware survey covered 1421 active Spring professionals, of whom 48 percent were developers, 28 percent architects and 19 percent managers. 49 percent were in Europe, 26 percent US or Canada, and others were scattered across the globe.

Native compilation is hot in the Java world, with Oracle contributing GraalVM to OpenJDK last year, and the Spring Native project uses the technology to speed start-up time and reduce memory usage. 43 percent of those surveyed have tried Spring Native and 79 percent intend to deploy a Spring Native application within 2 years. A key motive is to save on hosting costs, and to use native compilation with containers and Kubernetes where the smaller footprint is a good fit.

Another key topic is Project Loom which brings virtual threads to Java, currently in preview, which can also reduce the memory footprint of applications. “Of those who have heard of Project Loom, almost all (90 percent) have a positive view of the technology,” the report said, and 30 percent plan to use it, though the report adds that “Loom is nearing the peak of the hype cycle.”

The survey also asked about challenges in the Spring community, the biggest one being “steep learning curve,” which rose this year to 26 percent of respondents. Spring developers also struggled with issues like “hard to understand what all the components do” and “lack of information about how to use modules together.”

VMware, which sponsors Spring, promised to “work harder” in 2023 to help developers with these challenges.