JNI or Flash interface?

[marchywka]

Could someone please provide a link which documents any JNI or similar interface that may allow combining Java with native code or, even better, an interface to the Flash Player ? I'd like to write applications in MIDP2.0 Java while implementing CODEC's or similar computationally intensive algorthms in optimized native code. However, I have not found documentation on this- all the mobile stuff seems to be implemented in one technology only. I found some interesting stuff using Flash and native code on a Pocket PC for mail handling ( iirc, this was from IBM). I'm sure that are other examples of mixed implementations on mobile devices but I haven't had much luck finding any.

Thanks.

[petrib]

There is no JNI or equivalent for/from MIDP 1.0 or 2.0 on any phone, as far as I'm aware. That's probably why you haven't found any documentation of such.

More possibilities, if you switch to Symbian OS based devices and C++ (Series 60, Series 80 or the 7710). There's also at least a Flash Lite player for Series 60 available from Macromedia (and presumably it will be built-in on - at least some - future Nokia Series 60 phones according to last months press releases by Nokia/Macromedia).

[marchywka]

Thanks. I noted you replied to my related message so I will reply to both here ( and I'm having a few problems navigating these forum screens). Flash apparently has something called JSAPI which is the JavaScript interface that also supports C-level extensibility:
http://www.macromedia.com/support/do...tion/en/flash/

I'm really surprised that people who recognize the limitations of mobile devices and have some experience with Java did not envision either a need to use native code or at least provide an api to make native resources available to pure java code. A JVM with no JIT compiler combined with limited memory and processor speeds appears to handicap Java for many applications.

Thanks again.

[petrib]

Probably 95% or more of MIDP Java enabled mobile phones sold give no access to develop native code.

So, developers writing midlets will not need that feature for the vast majority of devices, so JNI won't help (you can't write and deliver native code to call). Developers who have access to the native system (= phone manufacturers) can do it, if they need/want it (and they have, obviously).

On phones with pJava/PersonalJava or PersonalProfile, CDC JVM vs. CLDC JVM, etc., additional options such as JNI are available. Witness, e.g., Nokia 9210i/9500/9300 or the UIQ based phones, when discussing Symbian OS based phones.

The problematic area is then the Series 60 style smartphones with native OS development capabilities + MIDP with its limited access. Things have improved there with, e.g., JSR-75 support added, etc.

Eventually, processor/memory price/performance will surely change this.

In other words, it is not as if it hasn't been thought of (it obviously has, and has been solved when practical or making economical sense, but not everywhere for every kind and class of device yet).