The latest Debian Busty offers Java 11 via OpenJDK. There’s also a comment on the OpenJDK web site that from now on all official Java releases are done via the OpenJDK (site/framework)... does that mean one no longer has to wonder about Java vs OpenJDK compatibility? That would be nice.

Of note: Debian has an openjdk-11-headless… no more need to drag X libs pointlessly.

It also begs the question of “what’s new in Java 11”... and what can be used on Android.

https://simply-how.com/getting-started-with-java-11

• Java 9:
• A new concept of “modules”, a “self describing collection of code and data”.
• Jlink, a tool with a link time phase vs compile time phase, using modules.
• Jshell, a REPL … that can come in handy.
• Multi-release JAR files: version-specific of classes in the same JAR.
• Private methods on interfaces, which can be used by default methods.
• Rx compliant Flow API.
• Factory/collections methods: Set.of, List.of…
• Stuff I don’t care, e.g. garbage collector changed. (skipping those below).
• Java 10:
• “Var” keyword for local type inference.
• Optional.orElseThrow.
• Unmodifiable collections: List.copyOf, etc.
• Java 11:
• HTTP Client API (do I care?)
• “Singe-file source-code programs”... sounds like scripting to me.
• “Var” keyword can be used in lambda parameters.
• Java 12:
• More garbage collector whatever this or that.
• Mostly nothing except some *preview* of a condensed switch/case/break syntax (e.g. the “break” also acts as a “return”, and can be further condensed to an -> arrow syntax)... meh.

Bottom line: mostly nothing to see here.

So overall a fairly incremental update to the language. The most notable useful thing is the “var” keyword. Since it is type-inference, I expect it can generate backward-compatible bytecode running fine with older JREs. New APIs like collections would obviously require the latest JRE to run.

We still don’t have support for “safe-dereference” (?. which was proposed for Java 7!) and folks horrendously suggest using Optional instead.

For gradle, the usual:

targetCompatibility = 11

sourceCompatibility = 11

Or

compileOptions {

    targetCompatibility JavaVersion.VERSION_12

    sourceCompatibility JavaVersion.VERSION_12

}

Thus it seems to me overall I’d want something along the lines of “target 8… source 11”.