As reported, the JRuby team recently started a debate about whether they should move to requiring Java 5. A decision has been made reports JRuby team member Ola Bini:
Users limited to Java 1.4 are supported, as the JRuby team will build a version treated with Retroweaver, which takes Java 5 code and exports classes compatible with a Java 1.4 VM. Another similar tool is Retrotranslator. These tools go quite far in Java 5 support. Both even allow features such as Annotations to work on Java 1.4.
So, after some discussion on the #jruby IRC channel, the core team has decided to go with a 5+ strategy on trunk. The reasons for this is that almost everyone who commented on the issues advised us to move on, and the features of 5 is quite compelling.Part of the reason was the ability to use new language features to implement the JRuby runtime. Java 5 Annotations, for instance, are now used to provide metadata for method bindings. Another area was the ability to use the Concurrency libs included in Java 5. JRuby 1.0 ships with a backport of these libs, but they don't come with all the performance improvements the bundled equivalents on Java 5 provide.
Users limited to Java 1.4 are supported, as the JRuby team will build a version treated with Retroweaver, which takes Java 5 code and exports classes compatible with a Java 1.4 VM. Another similar tool is Retrotranslator. These tools go quite far in Java 5 support. Both even allow features such as Annotations to work on Java 1.4.
Community comments
And 1.0 branch will remain 1.4-compatible
by Charles Nutter,
XRuby binds Ruby method with Annotation
by Zheng Ye,
Right decision
by Taras Puchko,
And 1.0 branch will remain 1.4-compatible
by Charles Nutter,
Your message is awaiting moderation. Thank you for participating in the discussion.
Just a reminder, we have no intention of migrating the 1.0 branch to Java 5, so anyone using 1.0 will soon see a 1.4-compatible 1.0.1 release.
XRuby binds Ruby method with Annotation
by Zheng Ye,
Your message is awaiting moderation. Thank you for participating in the discussion.
Thank JRuby team!
The new release of XRuby 0.3.0 has implemented method binding with Annotation, which is inspired by this discussion. That's really a wonderful idea! It makes code cleaner.
Right decision
by Taras Puchko,
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I think you've made the right decision. Using Java 5 is a great deal for developers and will benefit clients too.
BTW, in addition to language features and API another reason to move to Java 5 for many projects is an ability to use new frameworks and libraries like the JPA or JAX-WS implementations. And as the developer of Retrotranslator I can say that with little effort most of Java 5 libraries can be made to run on Java 1.4.