I just started to use the Java ScriptEngine to do little extensions to my Application then i noticed that i can import all the java classes in the script and use them withou
I solved this by putting "importPackage = null" on the top of all scripts, it seems to work but Im not sure if this hack can be avoided.
Well, you seem to need to learn about the Java SecurityManager. That's a pretty large topic, you might want to read up on it and then post a more specific question if you have trouble making it work for you.
Use the Java Security Manager. Refer this answer for an example.