The Java API access on China Unicom has stirred some discussion on our discussion boards. I have to admit that I am not so familiar with the CDMA operator's behavior around Java API access and security domains, and even less familiar with the operators in Asia region (a lot of the important developer information is in languages I cannot read).

As far as I understand, unsigned (untrusted) MIDlets do not have access to platformRequest, network connectivity (neither HTTP nor Socket), messaging, reading/writing user data (files and PIM), and a couple of UniJa extensions (3D Graphics - com.chinaunicom.m3g - and Standby mode; I am not sure how these work, as I cannot read Chinese...)

China Unicom has some kind of testing certificates available for developers, but I have no information how to apply for one.