The need for Spring development skills is outstripping demand for more traditional Java programming. It's the ascendency of lightweight, Java programming over the traditional heavyweight approach, where the programmer knows complex Enterprise Java APIs.

Spokesmen for SpringSource, the company behind the Spring open source Java framework, say that job listings for Java projects that require Spring now outnumber those that want Enterprise Java Bean-building skills, the hallmark of traditional Enterprise Java programming.

At the job search aggregator site, Indeed.com, SpringSource CEO Rod Johnson says 7,539 Java projects are currently seeking programmers with Spring skills versus 5,437 seeking Enterprise Java Bean skills. Indeed.com aggregates jobs listed on thousands of Web sites, including newspaper want ad sites, online job board postings, professional associations and company career pages. Spring beating EJB experience at Indeed.com makes its ascendency official -- sort of.

By another measure, the Spring Framework is downloaded 120,000 times a month from the SpringSource site [it's also available from other sites, without counts being available], but Johnson concedes that downloads do not necessarily reflect installation of the software for business use. Many downloads reflect newcomers who are evaluating the product, he noted in an interview.

The job postings are a better indicator of demand for Spring than downloads of the framework's code. The job listings "show spending on projects of business importance," he said.

Spring at first was denigrated by experienced Java programmers as offering too many shortcuts in its attempt to sort out and simplify the Enterprise Java environment. But time-pressured project managers grew to appreciate how Spring sped up the development process over traditional skills sets. Building a sophisticated application as a set of linked components can be done either with Enterprise Java Beans or Spring modules, but the Spring Framework's early mission was to take complexity out of the task.

The Spring approach lets developers produce modules of Java business logic and then an underlying platform supplies the interfaces to the network, Web services, databases, or other elements the developer wishes to connect with.

The job listings are one of several indicators of Spring's growing strength in the enterprise. Oracle has built a Spring interface into its JDeveloper Java tool and SpringSpource has produced a runtime environment for Spring applications that works inside the Eclipse open source programmer's workbench, used by many Java developers.

Nevertheless, some Java projects are listed seeking more specific Java skills, such as those who want IBM Rational Application Developer for WebSphere, another Java coding tool, which shows up on Indeed.com as needed in 4,411 projects. Such tools can be used either with Spring or to build Enterprise Java Bean-based applications directly.

But in head-to-head searches of projects mentioning either Spring or EJB experience, Spring has been winning the count by an increasing margin for four months. According to a chart produced by Indeed.com, Spring skills appeared to pull even with Enterprise Java Bean skills last January, with the two matching each other through the winter; then Spring pulled decisively ahead.

The chart may not resolve an old debate within the Java community over which direction Java development should go, but for Johnson, it was evidence enough. "There's a landslide of Spring adoption," he said.

SpringSource is a company with about 100 employees. It has obtained 450 paying technical support customers after 18 months of offering the service.