However, due to the high computation cost in this operation, MIDP VM does not perform a complete run-time bytecode verification. Instead, application developers must deploy the application to mobile devices before the platform or stage in the development area on the pre-validation class. Pre-optimized implementation of the verification process flow includes instructions to create applications directory stack image, and then added to by the pre-stack image of the class file verification. At runtime, MIDP VM byte code quickly to linear scan, the effective instruction of each stack image with the right items to match. Because of the lack of a complete MIDP security model, so the number of disabled in the MIDP J2SE features to make the potential security risks to a minimum. For example, the core classes in order to prevent the illegal overloading, MIDP VM does not allow user-defined categories. MIDP does not support Java Native Interface, or reflection. Even if taken properly these security measures, not all byte-code verification by the code are allowed to run. Code signature is a J2ME application security strategy in the next important element.
Research firm Canalys data provided in the last year, global shipments of smart phones, Linuxs share of less than 6%, Symbian accounts for 67%, Microsofts software accounted for 14%, RIM accounted for 7%. Linux in the global shipment of mobile phones, Motorola accounted for 90%, other vendors, including Panasonic, NEC, and Samsung. Linspire 8 launch the latest Freespire 2.0 Linux desktop operating system version, is free to join other proprietary software vendors, drivers, and encoding / decoding process. Linspire to Ubuntu 7.04-based, and provides six categories of software, some of which contain proprietary software. So that the original user only to look forward to Yang Chunmian get a bowl of beef noodle soup accident.