Portable Java ME development

The last six months or so I have been busy with developing a new application in Java ME environment. I have done some work in this envirnment before, but even though the platform has not changed much, my impression is that the quality of the implementations have improved a lot.

The goal was to support a wide selection of mobile phones:
- Nokia, both System 40 phones and Symbian System 60
- Research in Motion BlackBerry, at least the latest models like Bold and storm
- Sony Ericsson devices, where we started with Symbian UIQ models and now target mostly Xperia X1, based on windows mobile
- Samsung
- LG
- Motorola
etc...

Main focus is on more powerful, smartphone segment, but the application works well also on smaller phones.

Java ME was not the only possible choice. There is always the possibility to use native tools, for Symbian and BlackBerry at least. Our choice was to start developing on Java ME and see if it works and later add Symbian and/or BlackBerry specific code if needed. So far we have not needed it. And what surprises me is that it now works very well and very portable. When we try a new device it almost always works right away. We might need to add some code to make better use of the keyboard or make it look better, but generally it works well.

It is actually more of a problem to make it work in emulator, which surprises me. A special problem is with hasPointerEvents() method, which is supposed to tell us if the device has a touch screen or not. Since the application changes its user interface slightly depending on if there is a touch screen available or not this is a very important method for us. And on the phones it always works, but in the emulator it does not.

Another problem with the emulators is to find a good-looking emulator for demonstration purposes. There are a lot of good devices out ther, like Sony Ericsson Xperia X1 and Nokia S60 phones, but I have not managed to find good emulators for them. For the X1 I have so far not found a Java ME emulator at al, and for S60 phones there is one, but it does not look good enough for demonstration puposes. Guess this is because the development of new devices is so fast that manufacturers don't have the time to fix emulators.