Mobile Java Platform

Terrence Barr - Evangelist, Java Mobile & Embedded Terrence.Barr at Sun.COM
Thu Feb 1 15:37:30 CET 2007



Bob Deanna wrote:
> Terrence,
> 
> Your assessment is right on target.  PhoneME or JamVM are probably the
> best bests.
> 
> I think most Java developers would prefer CDC, rather than CLDC because
> CLDC is geared for Java clients and is pretty limited as a result.

Not sure I agree. Both worlds have benefits and it really depends on
your target market and audience. There is a lot of functionality (JSRs)
that are available only in Java ME at the moment. Having both is best.

> 
> A port of Mono (possibly by the Mono folks) would be awesome too, since
> that would open the device to .NET developers.

I'd be curious to know where Mono stands these days.

> 
> The other spec to keep in mind is MIDP 3.0.  Arguably, this may be the
> most important Java spec to have support for on the device.
> I assume PhoneME would ultimately support such.
> 
> There are a lot of great features targeted for MIDP 3.0/JSR 271
> (faceless midlets, midlet daemons, inter-midlet communication...to name
> a few).
> See:
> https://opensource.motorola.com/sf/sfmain/do/viewProject/projects.jsr271
> 

Yes, MIDP 3.0 is very important. phoneME will have a MIDP 3.0 implementation
so doing a phoneME port to Neo now would naturally make MIDP 3.0
available when it's ready.

-- Terrence

> Regards,
> Bob
> 
> -----Original Message-----
> From: Terrence.Barr at Sun.COM [mailto:Terrence.Barr at Sun.COM] 
> Sent: Wednesday, January 31, 2007 4:00 AM
> To: Christopher Heiny
> Cc: openmoko-devel at lists.openmoko.org; Bob Deanna; scottoberg at gmail.com;
> koen at dominion.kabel.utwente.nl
> Subject: Re: Mobile Java Platform
> 
> Chris,
> 
> There is quite a lot of interest in Java on OpenMoko, both from the Java
> SE as well as the ME perspective. I think Java will be critical to the
> success of OpenMoko given the huge software base that would be instantly
> available once the Java stack(s) are ported to OpenMoko.
> 
> Based on the specs of Neo 1973 I believe Java SE is possible but it
> would probably tax the system quite a bit so I think it is not a slam
> dunk.
> 
> There are two important parts to a Java SE port:
> 
> - The VM itself
> - The class libraries
> 
> As for the VM there are several open source options such as JamVM,
> Kaffee, Cacao, and Apache Harmony. Of course, now there is also Sun's
> Java SE implementation that is being open sourced under GPLv2
> 
>    http://www.sun.com/software/opensource/java/index.jsp
> 
> As for the class libraries there is really not much point in reinventing
> the wheel here multiple times. The GNU Classpath project is seriously
> considering moving to Sun's class library implementation now that it is
> under GLPv2. I expect that eventually the market will rally around Sun's
> implementation.
> 
> As for the effort of a complete and functional Java SE port I can't
> really make a statement ... I haven't worked on such a port before.
> Since compatibility with other Java SE implementations is key there will
> have to be a lot of focus on compatibility and testing (including
> running TCKs).
> 
> Java ME (both CDC as well as CLDC configurations) are both a good match
> for the Neo 1973 specs. CDC is based on Java 1.3 so that gives you a
> high level of funcationality. CLDC is a subset of CDC and has the
> advantage of running the MIDP profile which is present on nearly a
> billion phones today.
> There are a lot of interesting things going on in the Java ME space,
> including very cool UIs and Web 2.0-type applications.
> 
> As for open source Java ME stacks the options are fairly narrow. There
> are some Java ME VMs in open source but I think they are all somewhat
> lacking resources and are incomplete (correct me if I am overlooking
> something). But since Sun has also released it's entire implementation
> of both of it's Java ME stacks I suggest this is the way to go:
> 
>    www.mobileandembedded.org
>    https://phoneme.dev.java.net/
> 
> phoneME Feature is a full-featured, product-quality CLDC/MIDP stack with
> additional JSRs. phoneME Advanced is a product- quality CDC/FP/PP/PBP
> stack for advanced mobile and embedded devices.
> 
> Both are developed in the open and present the cutting edge of the Java
> ME platform market. They are designed for portability and have been
> ported to a number of platforms already, amongst them Linux on ARM.
> 
> So I think phoneME is an ideal candidate for OpenMoko.
> 
> Where to go from here:
> 
> I am working with Sean on how we can proceed. I believe it would be best
> to create an official phoneME sub-project for the OpenMoko port so that
> it becomes a part of the standard phoneME repository. As a side effect
> the OpenMoko effort can then leverage the expertise and infrastructure
> of the phoneME (Mobile & Embedded) Community.
> 
> Let me know if that answers some of your questions.
> 
> PS: SuperWaba is *not* Java. I know SuperWaba has been around for a
> number of years and is based on the open source Waba project but I am
> not sure how much traction it has. There is a lot of innovation and
> market penetration of Java ME that SuperWaba is not participating in so
> it appears like a niche solution.
> 
> -- Terrence
> 
> Christopher Heiny wrote:
>> [I've cc'ed some folks who expressed interest in Java on the community
> 
>> list (at least in the messages I've kept around).  I don't know if 
>> you're on -devel - if you are, I apologize for the double posting.  If
> 
>> you're not actually interested in Java on Openmoko, I'mm sorry to have
> 
>> bugged you.]
>>
>> On Tuesday 30 January 2007 11:38, Jonathon Suggs scribbled in crayon 
>> on the back of a kid's menu:
>>> I had looked into developing some applications based on this platform
> 
>>> a while back and just got an email about it latest version.  Anyway, 
>>> I don't know how much work it would be to get its VM ported to our 
>>> platform, but if we did then we could instantly get more applications
> 
>>> that were compatible with our device.
>>>
>>> >From their website: SuperWaba is an open-source software development
>>>
>>> platform for PDAs (Personal Digital Assistants) and Smartphones.
>>> http://www.superwaba.com.br/en/default.asp
>>>
>>> Let me know what you guys think...
>> Hmmm.  It's hard to tell on a 5-minute examination whether the 
>> Professional version is fully opensource or not.  Their comparision 
>> page indicates that you need the $495 SuperWaba professional to get 
>> image handling, email, html, ftp, and printing.
>>
>> Of the options that folks have mentioned on the community list, I 
>> think JamVM might be best.  I believe that it's already checked into 
>> OpenEmbedded, so it should be easy for it to be part of OpenMoko.  An 
>> email here
>>     
>> http://lists.linuxtogo.org/pipermail/openembedded-devel/2006-December/
>> 001036.html Koen describes some first steps on getting Java installed 
>> and going (note that the PDF linked in that mail is broken).
>>
>> I noticed that the projects.openmoko.org appears to be up and running
> now.  
>> Maybe we should set up project with the goal of getting Java going on 
>> OpenMoko (probably via OE) and maintaining it?
>>
>> 					Chris
>>
>> [Disclaimer: Though I've been messing around with J2SE for about 8 
>> years now, is is my first venture in the ME world of Java.  It's kind 
>> of an unfamiliar & bewildering territory, so please correct any 
>> egregiously boneheaded statements I might make.  Thanks.]
>>
> 
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