Re: Technologies for Consideration: Java ME ~ What's the deal?

[Ken Gilmer <ken buglabs net>]

Hey Ross,
> Basically this means that we know that JavaME exists and is used by  
> some
> people, but there needs to be more research done to see if it  
> should be
> added as a recommended component, needs work to be better integrated
> into the GNOME Mobile platform, and so on.

Got it.

> This is where you probably know more than the rest of us: what is the
> state of JavaME and GNOME Mobile integration?  (I'm very out of touch
> with Java now, so bear with me)

I'm CCing Robert Schuster from Jalimo [1], as he knows more than me  
on this, but from my understanding there is a J2ME UI on GTK+ with  
midpath [2].  I have not seen this myself but I think it has been  
used on the OpenMoko device.

> Is there an AWT or Swing implementation
> with a GTK+ backend?

Yes, CACAO with GNU classpath supports GTK+ backend.  We have done  
some preliminary work with our device with success [3].  JamVM should  
be able to use classpath's GTK+ peers as well, however I haven't seen  
this.  Currently PhoneME only supports AWT with QT3 peers but there  
seems to be some activity in a GTK+ port [4].  Bug is interested in  
this work as well.

>   Are there usable DBus bindings?

This is something I'll be looking into in coming weeks with dbus-java  
[5].  My understanding is that it's at least possible with CACAO.

> How about the
> rest of the platform such as GConf, GIO and so on?

I haven't heard anything regarding either of these.  What components  
of the platform would need Java bindings in order to become a part of  
Gnome Mobile?

> Are some VMs better
> integrated than others, or do most open VMs these days all use
> Classpath?

CACAO and JamVM use GNU Classpath but there is work under way to let  
them use OpenJDK class libraries as well [6].  This is a very  
interesting development.  PhoneME has it's own class library and is  
not able to use others.  One key limitation of PhoneME is that it  
does not contain a classpath exception.  There has also been some  
success in building OpenJDK VM and classpath for ARM-based devices,  
although I think that's still in early stages.  We have done some  
work [7] [8] in benchmarking various JVMs on BUG but I wouldn't  
consider them complete, there is still some important optimizations  
for CACAO that we haven't yet got worked out.

In general I'd say that CACAO + GNU Classpath may in fact be a  
suitable candidate for Gnome Mobile.

> Answer these questions well Ken, and I may bring more Laphroaig... ;)

Uh oh...I think my liver still hates me for what happened on that  
boat ride... :)

cheers
ken

[1] https://wiki.evolvis.org/jalimo/index.php/Main_Page
[2] http://midpath.thenesis.org/en/Start%20Page
[3] http://bugblogger.com/working-with-processing-on-bug-214/
[4] http://forums.java.net/jive/thread.jspa?messageID=275587&;
[5] http://dbus.freedesktop.org/doc/dbus-java/
[6] https://c1.complang.tuwien.ac.at/cacaowiki/OpenJDK
[7] http://bugblogger.com/java-vms-compared-160/
[8] http://bugblogger.com/java-vms-compared-ii-187/