The $Proxy245 is a generated proxy class by some AOP framework in your case it's not clear which one. It's used to intercept method calls. Since it's generated, you will not find the actual sources because there aren't any. I suggest you to produce a Thread Dump with VisualVM (Threads tab) and check the stack traces I'm pretty sure you will find this method (maybe not for the first try, but do several dumps). With this you can find the chain of methods which at the end call this (proxy) method.
Also try to Profile the application not only Sample (Profiler tab). With the profiler you can find out if these are several calls to the same method or just one long call that doesn't want to end.