Java. Gathering data for tests from production

Preparing of test data not an easy task, so I want to aggregate test data from running production server to do a component-level regression testing.

As I am in Java world I can use Java Instrumentation Api with Java Agents or more high-level AspectJ tools to log component method calls arguments and return values and then write tests using accumulated data.

But maybe there are easy ways or ready solutions? or some tools that automates writing tests based on data that was obtained this way?