How could I call Java code dynamically?

Question

How could I write Java code that is executed like javascript code used together with the eval function?

What I would like to achieve would be something like this:

Answer 1

I've used the JavaScript engine shipped with Java 6 and it works quite well. The performance of the engine is very very decent.

Check the page http://java.sun.com/javase/6/docs/technotes/guides/scripting/programmer_guide/index.html