Jsr 82 and portability

Question

Hello,
I'm currently writing a MIDP application which uses some
optional packages, namely JSR 75 (FileConnection API) and
JSR 82 (Bluetooth API).
I'm aware you can test the presence of those APIs with
<code>
System.getProperty("microedition.io.file.FileConnection.version")
</code>
and since there is no System property to indicate JSR 82 presence
you can try to load a class from that package:
<code>
try{Class c = Class.forName("javax.bluetooth.DiscoveryAgent")} catch (ClassNotFoundException e) {}
</code>
Now that I know that JSR 82 is present, I could use a btspp:// connection to communicate with a server. If JSR 82 not present,
then I would use a socket:// connection.
But my code fails, if JSR 82 is not present. It's somewhat strange --
I can use the LocalDevice and DiscoveryAgent classes in my code
when I make sure they are not reached if JSR 82 not present (see code below). I Think this is only possible, because the KVM itself doesn't verify if all classes as this is done in a preverification process. So using these classes is not a clean solution, but I have no other idea right now.
<code>
if (jsr82present) {
     //do device discovery
     LocalDevice local = LocalDevice.getLocalDevice();
     local.setDiscoverable(DiscoveryAgent.GIAC);
     DiscoveryAgent agent = local.getDiscoveryAgent();
     //fails in the next line, although this code is
     //never reached when jsr 82 not present
     agent.startInquiry(DiscoveryAgent.GIAC, new DiscoveryListener(){
          //interface methods here
} else {
     //establish socket connection
</code>
My code fails as soon as I use "new" to instantiate a DiscoveryListener (which is also part of JSR 82) -- even if the instance will never be created, since a device with no JSR 82 support would never reach this code. See my problem now?
Does this mean I have to write two different applications, one for bluetooth communication and the other one for sockets?
I've tried to get around this with dynamic classloading, but didn't work either:
<code>
Class c = Class.forName("mypckg.MyDiscoverListener");
c.newInstance(); //<-- fails here
</code>
Has anyone an idea how to write one application for different devices with different optional packages installed, which uses all functionality
the device offers through it's optional packages?
Or is it just impossible?
Regards,
Torben

Answer 1

try this link
http://www.jcp.org/aboutJava/communityprocess/final/jsr082/