java - Is there a way to get which classes a ClassLoader has loaded?

Question

I am trying to implement some unit testing for an old framework. I am attempting to mock out the database layer. Unfortunately our framework is a bit old and not quite using best practices so there is no clear separation of concerns. I am bit worried that trying to mock out the database layer might make the JVM load a huge number of classes that won't even be used.

I don't really understand class loaders that well so this might not be a problem. Is there a way to take a peak at all the classes a particular ClassLoader has loaded to prove what is going on under the hood?

Answer 1

You can create your own Classloader and use that to load during the unit test. Have your own custom Classloader print out what it's doing.

Or if you just want to know which classes are loaded, do:

java -verbose:class