Do I need to call the init method with my own ScriptContext, and I have an exception
Do you don't, the framework will do it for you.
Javacript
I have an exception when I use my Javascript script, some objects are not found
It is possible that you are using the script in a Swing or JavaFX Thread, but that you created the wrapper in another Thread, which can lead to problems with Rhino. See managing the Javascript context for how to solve this problem.
Debugging
I try to debug a Ruby / Python / Javascript script, but it does not work