Not that you'll ever need this, after all your code is perfect. But I did run into a situation where I wanted to figure out what exactly is wrong with my ADF Mobile code. The way to do debugging is documented in the ADF Mobile Developer Guide, but here is a version of those instructions with nice pictures (which might make it easier for you to find files etc).
1. First locate the cvm.properties file (In the Application Resources accordion). In this file you'll want to change the value of java.debug.enabled to be true. Also note in this file the value set for java.debug.port, by default this is 8000 and we are going to keep that default value in our example.
2. Next have a look at your application level deployment profile, or even better create a new deployment profile and call it debugDeploy. The key thing here is to make sure your build mode is in Debug mode and not Release mode (remember the previous post where we told you that Release mode creates a smaller/faster deployment, but right now we do need the bigger package to be able to debug).
3. Next deploy your application with your new debugDeploy profile. We'll assume deployment directly to the device.
4. Now from the command line locate the directory where your Android's SDK adb.exe utility is and issue the following command to let the device (-d) know that we are going to use port forwarding for debug:
adb -d forward tcp:8000 tcp:8000
5. Now on your device start your application. You'll notice that it seems to be stuck, well this is because it is waiting for the debugger to connect to it. So what are you waiting for?
6. In JDeveloper, stand on your viewController project and right click to choose debug. If you changed the port number you'll need to update that info in the dialog that pops up - but if you kept it at the default 8000 we should be ok.
The debugger will now try and connect to your running application, and will stop at the breakpoint you set.
By the way if you want to debug on the emulator of Android the only difference will be in step 4 where instead of -d you'll use a -e .
P.S. - you might also be interested in this blog entry about setting up logging on Android with ADF Mobile.