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JavaME for Palm

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ebresie
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Joined: 2003-08-06
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Hey guys, as a Palm / Treo user and a big supporter of Java...

It appears that support of Java on Palm is not being as widely supported as it use to be ( http://blog.palm.com/palm/2008/01/last-chance-to.html ).

I would like some feedback on the possibility of including a Java ME port of some type for Palm OS (not PocketPC, Windows Mobile, etc) based smart phones.

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kpimm
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Joined: 2006-02-07
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I have a J2ME midlet which I have developed against the following profiles: CLDC 1.1 & MIDP 2.0. I would like to be able to run this midlet on Palm OS.

All sources point to IBM J9 jvm as the solution, but I cannot find anywhere to download the jvm or a toolkit to convert the jad/jar files into prc. All my Google searches point to the Palm Developer Network website, but they are no longer offering the download. I'm assuming there was a free toolkit of some kind offered by PDN.

Can someone offer up a URL for downloading one of these toolkits?

Thanks!
Kevin

fyi,
I have found Sun's midp4palm, but as far as I can tell, this is only CLDC 1.0 & MIDP 1.0 compliant.

terrencebarr
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Joined: 2004-03-04
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Eric,

Unfortunately, there's more. Java ME CDC only supports Java 1.4.2 while CLDC supports even less so any Java code that uses new language features won't work. Also, the security model in CLDC is very different. Finally, most Java ME APIs (from optional JSRs) assume CLDC/MIDP underneath (security, GCF, etc) so again code is not fully compatible between "big" and "small" Java. Not an ideal situation, for sure, but a historical development.

So between CDC and Java SE the differences are fairly straightforward but the mapping between CLDC and Java SE is not trivial at all.

-- Terrence

terrencebarr
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Joined: 2004-03-04
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Hi again,

Yes, the best place for phoneME Feature porting questions is:

http://forums.java.net/jive/forum.jspa?forumID=99

The forum for general phoneME issues (phoneME Feature and Advanced) is:

http://forums.java.net/jive/forum.jspa?forumID=115

The complete set of documentation for phoneME Feature starts at

https://phoneme.dev.java.net/content/mr2/index_feature.html

OpenJDK and phoneME has nothing in common except for the subset of the language they implement. So, yes, it would be too much work to combine the two. Plus, OpenJDK is way to complex to run on Palm I suspect.

Hope that helps,

-- Terrence

ebresie
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Joined: 2003-08-06
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> Hi again,
>
> OpenJDK and phoneME has nothing in common except for
> the subset of the language they implement. So, yes,
> it would be too much work to combine the two. Plus,
> OpenJDK is way to complex to run on Palm I suspect.
>
> Hope that helps,
>
> -- Terrence

Maybe I am over simplifying it, but isn't the difference between the full JDK and the ME JDK is ME is a subset of the libraries (minimal Math for example), with a different VM for the target platform. If most of the libraries and upper layers are written in Java this would minimize changes. So could you just have an ant build task (or whatever build system is currently in use) to have a build-me task of some type?

I compare this to Linux which has a large source base which includes builds for many different platforms including some small resource platforms. I give you there are some distribution that focus on the needs of the lighter platforms, but they still are based on the main linux source base.

Eric

terrencebarr
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Joined: 2004-03-04
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Yes, the Squawk VM is now open source. However, while Squawk is CLDC/IMP-compliant it targets a very different set of devices (embedded, low-cost, low-resource). Since Palm devices tend to be higher-end these days you'll want the features of phoneME (HotSpot JIT, optimized performance, support for a bunch of optional JSRs, etc).

Porting phoneME is your best option. Sure, a full-blown phoneME port does constitute a sizable effort due to the flexibility, it's modularized architecture, and the number of platforms it is capable of supporting but in the end you'll also get the best set of features and performance.

-- Terrence

ebresie
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Joined: 2003-08-06
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Terrence (love the podcast by the way) is there a better place to direct porter types of questions in the ME space? Which forum group? I'm guessing this is for ME application development and probably off topic. I know on OpenJDK there is a porter group. Does something similar exist for ME?

Is there any good "How to Port to a new platform" material somewhere? Thanks ahead of time. After looking around, I suspect

http://wiki.java.net/bin/view/Mobileandembedded/PhoneMEAdvanced

might be my best bet. Any other suggestions?

And on a broader sense, if Phone ME is basically a subset of the SE, would it be better to combine efforts, and have builds of the OpenJDK with some tasks for building ME (or specific ME platform) or is that just too much work or too different? This has the added benefit of making migration of ME to SE as phones get more powerful, a little easier.

ebresie
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Joined: 2003-08-06
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This is something I stumbled across. I am not familiar enough with the project just yet, but would a port at the Squawk VM be a step forward towards this? See https://squawk.dev.java.net/.

Roger Brinkley

meappdev-interest@mobileandembedded.org wrote:
> Hey guys, as a Palm / Treo user and a big supporter of Java...
>
> It appears that support of Java on Palm is not being as widely supported as it use to be ( http://blog.palm.com/palm/2008/01/last-chance-to.html ).
>
> I would like some feedback on the possibility of including a Java ME port of some type for Palm OS (not PocketPC, Windows Mobile, etc) based smart phones.
> [Message sent by forum member 'ebresie' (ebresie)]
>
>
Including in the wrong word to use here, developing is the right word.
This would have to be a community level development and yes it's
possible. We're currently working on the Nokia N800 series in the community.

binky

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ebresie
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Joined: 2003-08-06
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Where would be a good place to look for developing Java ME for Palm OS?

Should I be addressing these questions to a different Forum group? If so, where would be appropriate?

sfitzjava
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Joined: 2003-06-15
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Actually there is already a JavaME vm for the Palm devices.
It's the IBM J9 product. If you go to the palm support pages for the
smartphone devices you should be able to select your model of phone
and services provider then look for Java support. That should take you
to something like the link below:
http://www.palm.com/us/support/jvm/

While some folks don't like the J9 product, I have had only moderate issues
when using HTTPS and certficicates for SSL connection. Everything else has
been relatively okay.

Yes it would be great if we had a way to build any number of implementation
for devices of the JavaME VM, but unfortunately the ability to easily port or even
compile the PhoneME products to various platforms is overly complex, and relies
on specific products and the use of a JavaSE VM to compile other parts. (makes
cross-platform compiling a nightmare)

If you want to use the Java Syntax, but aren't a total purest wanting Sun approved
tools, then you might want to look at SuperWaba. http://www.superwaba.com.br/en/default.asp

There are a few other contenders such as JamVM, using the Gnu Classpath project,
or ewe (windows and linux only), those being what I've worked with with a level of success.

-Shawn

ebresie
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Joined: 2003-08-06
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I've had no major problems with the IBM VM, my concern however is for the future. It took some time to get any update on the existing VM they did have.

I think this is the same sort of scenario that OS X users are encountering, having to wait for Apple optimized versions which are always lagging behind.

As Palm does not seem to be actively supporting Java, I was hoping a port could be integrated into the Java ME source tree and supported in the open community.

If it's included, then we (Palm OS users) get all the added performance and feature updates that the reference implementation does.