@mostafaz4:
Yes, you can just use the jars from JDownloader for compilation. But I would recommend to setup/use proper IDE and either
-setup IDE with full source (see
https://svn.jdownloader.org/projects/jd)
or
-setup IDE with those jars as dependencies (JDownloader.jar, Core.jar and those from libs folder)
With help of IDE it's much easier/less error prone to develop/debug plugins
Once done, just copy over the compiled .class files from your bin folder to your JDownloader instance