Oracle says Java 9 modules will be a boon for developers

Modularity to bring improved scalability and performance to Java 9


The module system planned for debut in next year's Java SE (Standard Edition) 9 platform will treat modules as a fundamental new kind of program component, with the system improving scalability and performance, a key Oracle Java official says.

In a blog post this week, Oracle's Mark Reinhold, chief architect of the Java platform group, discussed the goals of the module system. Chief among them is reliable configuration, to replace the "brittle, error-prone, class-path mechanism" with a means for program components to declare dependencies on each other. Strong encapsulation, which allows a component to declare which public types are accessible to other components, is also a goal.

"These features will benefit application developers, library developers, and implementers of the Java SE Platform itself directly," said Reinhold, "and indirectly, since they will enable a scalable platform, greater platform integrity, and improved performance."

Reinhold defined a module as a self-describing collection of code and data. Code within it is organized as a set of packages containing types, essentially classes, and interfaces. Data within modules includes resources and other kinds of static information.