It seems that many Java developers are unaware there is any way to find out where a given java.lang.Class object was loaded from. This seems to be desired pretty often when debugging "ClassLoader hell".

In fact it is quite easy to do it once you know how. But it is not easy to find out how. You need to use a ProtectionDomain, which is in java.security.* and so doesn't sound like it should have anything to do with this problem. So discoverability is poor.