How do I call a Custom Function in JMeter

I've created a custom function in JMeter开发者_运维技巧 that returns a n length string with random characters. Where should I define the function, and how do I call it?

As long as your function is in the jmeter classpath, you should be able to call it just like any standard function with ${...} syntax, as described here.

Do make sure your jar file containing your function is in lib/ext, or added to the jmeter classpath via search_path's input option

You can do this in a beanshell script or via a javascript call. See the manual on

functions and on the beanshell preprocessor.