During the opening night keynote at SpringOne2GX Juergen Hoeller, Principal Engineer at Pivotal Inc and Spring Framework project lead, outlined the company's high level plans for the Spring Framework.

The upcoming version 4.3 will be the final feature release of the Spring 4.x line. There are no changes in system requirements, so it will support JDKs 6, 7 and 8, servlet 2.5+ and so on. Hoeller highlighted refinements and bug fixes to the core dependency injection model along with a richer set of precomposed "convenience" annotations. Hoeller explained that these are essentially a composition of existing annotations similar to @RestController “which is just a combination of @Controller and @ResponseBody really, but we already provide it out of the box for you at this point. Some such annotations along those lines are going to come your way in 4.3.”

The convenience annotations are being explored in the spring-composed project on GitHub. Hoeller told InfoQ that “likely candidates for inclusion in Spring Framework 4.3 proper are @Get/@Post etc. annotations for HTTP mappings, @SessionScope etc. annotations for bean scoping, and possibly variations of @Transactional”.

The 4.3 backlog on JIRA also lists plans to update a number of third-party dependencies such as JUnit 4.12, the Jackson 2.5+ APIs, and the new JasperReports Exporter API.

An initial release of Spring 4.3 is expected in March 2016, with GA around April to May. “We're committed to supporting the 4.3.x line until 2019/2020, analogous to the extended life that 3.2.x has at the moment,” Hoeller told us.

During the keynote he also outlined some high-level plans for Spring 5.0. It will have Java 8 as a baseline, with support for JDK 9 and HTTP/2. Since Java 9 is expected in September 2016 the likely initial release will be around then, with a GA version later in the year.

A major focus for Spring 5 is reactive architectures including reactive streams with back-pressure, and reactive composition. Pivotal is developing an HTTP end-point processing model based on reactive streams. "It’s kind of a reactive web processing engine along the lines of Spring MVC with a lot of familiarity in terms of the endpoint style, programming model and use of annotations but with a first class arrangement towards reactive processing,” Hoeller stated. Experimental work is being done through the spring-reactive project.

Elsewhere at the conference Spring Boot has received a tremendous amount of attention. James Watters, VP of the Cloud Platform Group, cited download figures of around 1.65 million a month for Boot and an impressive list of customers including Disney, Sony, Experion, Citigroup, and Ford. He also announced that Pivotal Cloud Foundry has passed $100 million in annual bookings run rate in its first 18 months.