If JarToVXP fails, you can attempt manual porting. This requires Java and C knowledge.
High-level steps:
This is impractical for most users. Only do this if you are reverse-engineering for research. Convert .jar To .vxp
Instead of converting, run your .jar file on a PC emulator, record the gameplay, or transfer saves. Converting to VXP often results in laggy performance or missing features (like Bluetooth multiplayer).
Yes, if:
No, if:
The golden rule of retro mobile gaming: Match the file format to the device, not the other way around. If you want to play .jar games, buy a device that runs Java ME natively. If you have a .vxp phone, search for native .vxp games—they run far better than any converted jar. If JarToVXP fails, you can attempt manual porting
Search online for "MRE JAR to VXP converter" or "Java2MRE tool." Download the archive and extract it to a folder on your desktop. You should see an executable file (usually named Converter.exe or similar).