JDK 8 on the Out

Oracle will stop updating Java 8 commercially from January 2019. All focus now should be on the latest feature release Java 10 (with a nod to new kid on the block, Nashorn, from Java 9 onwards).

Remind me again - what is a REPL environment?

Suppose we are comparing various JavaScript engines for the JVM. One criteria for comparison might be whether they provide a REPL environment for the JVM - basically, an environment where you can type in quick commands to test out the language and interact with Java libraries dynamically.

More formally, REPL can be defined as a Read-Eval-Print loop, with the read function taking in the expression (rather than a full-fledged compilation unit), eval evaluates and print prints the result. JShell is a REPL included in the JDK since Java9.

New Version of JMC in Java 9

JMC6 is the new version of Java Mission Control in Java 9. JMC delivers Java monitoring and management. It supports automated analysis of so-called "flight recordings".

Java 9 Platform Module System (JPMS)

The JPMS is a major new addition to the Java platform and a product of Project Jigsaw, part of OpenJDK.

Mark Reinhold's State of the Module System is useful insight into the thinking behind JPMS and rethinking of the brittle classpath mechanism.

Project Valhalla as the Proving Ground for Prototyping Java 9 Features

JDK 9 is scheduled for 2016. Valhalla provides a testbed to trial new features as part of Open JDK. One of these is generics (removing type erasure). Brian Goetz's thoughts on these are here.