In Moving toward a modular
java, It have impacts on both developers and users. The changes made for
modular run-time images to java and now in JDK 9.Moving toward a modular Java,
Oracle is ushering in changes that have "significant impact" on both
developers and users, including breaking IDEs, a high-ranking Oracle Java
official said.
Project Jigsaw modularity
improvements had been intended for inclusion in Java 8, which was released in
March. But Jigsaw has been deferred until the release of Java 9. With
modularization, applications can use just the modules they need, offering
performance improvements as well secure boundaries between components. The
effort also is intended to make Java more scalable to smaller devices
Other changes in
modularization include JRE (Java SE Runtime Environment) and JDK images having
identical structures. Previously, a JDK image embedded the JRE in a jre
subdirectory; now a JDK image is simply a runtime image that set of development
tools and other items found in the JDK.User-editable configuration files that
were located in the lib directory now are in the new conf directory. Also,
internal file rt.jar, tools.jar and dt.jar have been removed, with the content
stored in a more efficient format in implementation-private files in the lib
directory.
A new built-in NIO file system
provider can be used to access class and resource files stored in a run-time
image. Tools previously reading rt.jar and other files directly need to be
updated to this file system.
