Just thought I'd share a couple useful resources on BeanShell and Jmeter.

The first of which is how you can create your own custom methods in Java which you can then port to Jmeter.

Custom Java BeanShell classes and methods in Jmeter | Capacitas's Blog

Through my experience, being able to use a programming language in order to manipulate variables in your Jmeter scripts has been invaluable. An example recently of this was having to decode a string into a URI friendly format. I was able to create a nice encapsulated class which had various methods such as DecodeURI(string s) and EncodeURI(string s) and use these methods in Jmeter with ease.

Testing BeanShell before using it in Jmeter | Capacitas's Blog

The second blog post talks about how you can test your BeanShell scripts before they go into Jmeter. This method is useful for simple(r) tasks were you don't necessarily need an IDE to help you to debug.