I've been looking for a code coverage viewer aimed at inspecting live Java applications, mostly webapps running inside an application container like Tomcat. Sure, there are a number of decent tools for getting automatic reports of unit test coverage, but my aim is more like learning in real time what an unfamiliar Java app does e.g. on a specific user interaction.
The Eclipse Java debugger (with JPDA for remote debugging) is really useful, but only if you are already familiar with the application's architecture. And in theory, I could take some coverage tool and set it up to auto-refresh static HTML coverage reports every two seconds, but this is far from optimal.
For Adobe Flex, FlexCover does just what I want by providing a coverage viewer tool that visualizes the coverage in nearly real time, and it's relatively simple to set up at least for somebody who knows the stuff. So is there a similar easy-to-set-up GUI tool, free or non-free, for Java?