Application of user defined class loader?

interesting topic that's not on the exam, moving this to Java General...

Is there even a question in there? I see some words followed by a question mark, but that doesn't turn it into a proper question. I have no idea what you actually want.

Rephrase Question : Can anyone mentioned the application names in which custom class loader is used?

Now its your turn.

One place where custom class loaders are used is in web application containers. Each web application needs to have a separate classloader, so that its classes can be separated from the classes of other web applications. If all webapps in the container would share the same classloader, it would for example not be possible to for one webapp to load version 1 of a library, and another webapp to load version 2 of the same library. Also, the webapps would be able to see each other's classes, which is not desirable.

OSGi container where each module requires to have its own classloader.

Custom classloaders could also be used to do various byte code transformations, or compile non-Java source files at load time, or...