how java app can be run on mobile phones ???

[mahdi68]

Hi
I have some question about java and jvm on mobile devices

java app how works on mobile devices like nokia s40 , ... ???
is any JVM or somthing like this on this devices for run java app ???
if there is no os on this devices how this jvm work ??? how it can boot on device ???
thanks

[r2j7]

Hello mahdi68,

you might want to check this related discussion thread on Forum Nokia Wiki: http://discussion.forum.nokia.com/fo...58-Java-Phones!!

Regards,
r2j7

[ektasrv]

Hi
I have some question about java and jvm on mobile devices

java app how works on mobile devices like nokia s40 , ... ???
is any JVM or somthing like this on this devices for run java app ???
if there is no os on this devices how this jvm work ??? how it can boot on device ???
thanks

Mobile phones like S40, have a smaller version of Java JVM called KVM in which java API's are limited to CLDC and MIDP API's. This KVM is installed on the device Native OS for example Nokia S40 has its Nokia OS on it and device boots in this OS.

[mahdi68]

why this os can only run java app ???
is this os open source ??? how about kvm ???

[ektasrv]

why this os can only run java app ???
is this os open source ??? how about kvm ???

This OS can run Java app;s becuse Java VM is preinstalled on it.

Nokia OS on S40 is not an Open Source OS.
KVM is just the small foot print JVM for mobile devices.

[Tiger79]

have you looked up what kvm stands for ? It's a small version of a jvm... The j stands for Java, so you might guess what it runs
Proprietary os'es are actually never open source, or at least not on the mobile platform (think of s40 OS, SE OS, LG OS, Samsung OS etc)...
Why it only runs Java ? Well you should ask Nokia, I guess it was enough to begin with and it was cheap, feature-phones have that in common : they are the cheaper range, otherwise you should aim for smart-phones (which are more expensive but alos can do more and might support multiple types of languages/apps, just like the S60 which supports java, flash, widgets, C++ etc)...

[petrib]

The Nokia OS on S40 phones also supports on most/all current models besides Java, also Flash Lite apps. I don't know if the latest S40 also supports web run-time (WRT) apps, or not.

In any case, as stated, Nokia has decided to limit the user-installable application development interfaces (APIs, Application Programming Interfaces) and runtime environments to these, instead of allowing/publishing APIs and tools for, so called, "native" application development. That's the case with most other manufacturers, too, when they use their own, proprietary real-time OS, instead of higher level OSs like Linux, Symbian, Windows, etc., where more options may be available.

Note, though, as examples:

Android (which is Linux based) allows only Google's version of Java for software development.

iPhone (which is BSD UNIX based) allows only Apple's Objective-C or Apple's web applications to be developed.

Windows 7 Mobile only allows Microsoft's .NET apps (earlier versions were more flexible, and many/most manufacturers also added Java support, etc.).

[Tiger79]

as a sidenote, Android actually supports C++ (native) development through it's NDK...