About Scala IDE and Java 7

By Luc Bourlier on Feb 20 2012

One of the comment from the roadmap post was asking “When is Java 7 support planned?”. This is likely to be a recurring question, so let me take some time to describe the current state.

Using Java 7

The question can be understood in two ways. The first one is “When can I start to use Java 7 with Scala IDE?”. And the answer is: right now.

Eclipse 3.6.2 is able to run Java 7, and the full support is part of version 3.7.1. Scala 2.9.1 is compiled for Java 5 and can be run on Java 7. The same is true for Scala IDE. So there is nothing stopping someone to use Java 7 for its whole setup. And from the information provided in tickets, some users do use Java 7.

That said, it might not be without problems. Eclipse 3.6.2 does not provide support for the new language features from Java 7, and some obscure problem are still being reported against Eclipse 3.7.1 (#364735). The changes in the Java Standard Library in version 7 might require changes in the user’s Scala code, which then make it incompatible with Java 6 or earlier (forum post). At least one ticket specific to Java 7 has but opened against Scala IDE (#1000820).

Explicit Java 7 support

The second way the question can be understood is “When will Java 7 be on the recommended list of VMs?”. Short answer: not planned right now.

The documentation will continue for the time being to discourage users to run Scala IDE on Java 7, at least until the problems occurring when running Eclipse on Java 7 have been clearly identified.

Eclipse support aside, there is no effort planned to solve potential problems specific to Scala IDE when running it on Java 7. It is a simple problem of resources and priorities. A big part of the contributors are using Mac OS X, for which there is currently no release version of Java 7. Of the other contributors, none has expressed an interest in taking on this task.

But Scala IDE is an open source project, and contribution are always welcome.

If you are using Java 7 and find Java 7 specific problems in Scala IDE, do create tickets.

Happy coding.