Comments on: Enums & GWT

By: Chaotic Java » Blog Archive » Enums, Generics and for-each loops in GWT 1.5

Sat, 05 Apr 2008 05:41:04 +0000

[...] the set of Java language features added to Java 5 by adding support for enums (much better than my workaround enum), generics and for-each loops. GWT itself even uses generics for the asynchronous calls, so that [...]

By: Adrian Smith

Adrian Smith — Thu, 07 Feb 2008 12:02:34 +0000

FYI: This has slightly different semantics from the Java 5 enums, as the Java enums are all singletons, and thus can be compared by identity, and don’t need to use the equals method.

http://www.databasesandlife.com/java-5-enums-can-be-compared-with/

By: Mark

Mark — Fri, 30 Nov 2007 15:32:21 +0000

Sorry, to correct that last post, I meant to say “I don’t use any of that stuff in client-side code,” not “I don’t use any of that stuff in Eclipse”.

By: Mark

Mark — Fri, 30 Nov 2007 15:30:36 +0000

You can feel free to use any level of JDK to compile, along with those options, when compiling your server code. GWT does its own compiling directly from source, and so as long as you keep track of what’s client (and server) and what’s ONLY server, you’re fine.

For example, my servlets and server code all use Generics, for-each loops, etc. I just make sure I don’t use any of that stuff in Eclipse. It takes some getting used to (for example, my Eclipse project is set against 1.5, so not everything that compiles in the project would compile under GWT), but it’s worth having stuff like Generics on the server side.

When it comes to anything serialized over RPC, though, you’re stuck with 1.4 on both the client and the server, as you’ve said. Clever solution anyway, and hopefully GWT 1.5 will come out soon (which includes J2SE 1.5 support)

By: Avah

Avah — Thu, 11 Oct 2007 18:20:52 +0000

For clarity’s sake: In private exchange of letters, I’ve approved it – and the code snippet can be found here.

Thanks Mohammad!

By: Mohammad

Mohammad — Wed, 10 Oct 2007 07:41:56 +0000

Can I post this code snippet to Wikicodia?

By: Avah

Avah — Thu, 04 Oct 2007 14:38:30 +0000

Kris: Maybe I was misunderstood. I didn’t mean I could compile with 1.5 options – I just compiled the server code against the JDK 1.6 (actually, the entire project – but obviously only the server code is being compiled using javac).

Basically, just point your dependency libraries (or classpath) to the JDK 1.6′s library. Then you can use stuff like java.util.concurrency etc.

By: Kris

Kris — Thu, 04 Oct 2007 06:31:49 +0000

Hi,
If I create an Eclipse project for GWT it creates a package for server code. How can I just compile the server package with 1.5 option? Or is there a better way to structure your project so you can leverage 1.5+ features on the server side code.

Thanks.