There are two possible location where your Java application can be installed, the Built-in phone memory and on your memory card. There is a folder, named ‘Private’, in each of these memory. You may only extract installed Java applications only if you have access to the folders. I prefer to install all my Java applications in my memory card, since the ‘Private’ folder will always accessible under the Mass Storage Mode (i.e. use your phone as a flash drive).
The location where all the Java applications are stored is: [Drive]:\Private\102033E6
All installed Java applications are installed are stored in its own folder under this directory. Simply find the application you want to extract, and copy the *.jar file (as well as *.jad file, if presents) on to another storage medium for later installations.
Why should we extract installed Java application?
For backup purpose: sometimes, we might face system crashes on our mobile devices and the only solution is to format it. In this circumstance, all our installed applications will be wiped out. We have to download them again if we want to use them. Thus, we can extract all our installed Java applications for later installation.
For sharing purpose: once you extract a Java application, you can send it to another mobile device that have the Java feature and install on that device too.