On-the-fly, in-memory java code compilation for Java 5 and Java 6

Question

How can I compile java code from an arbitrary string (in memory) in Java 5 and Java 6, load it and run a specific method on it (predefined)?

Before you flame this, I

Answer 1

You might want to check out Janino as well.

From their website:

Janino is a compiler that reads a JavaTM expression, block, class body, source file or a set of source files, and generates JavaTM bytecode that is loaded and executed directly. Janino is not intended to be a development tool, but an embedded compiler for run-time compilation purposes, e.g. expression evaluators or "server pages" engines like JSP.

http://www.janino.net/

Im currently using it in a pretty large mission critical project and it works just fine