Core: Hot load Java

https://segmentfault.com/a/1190000040825230/en
https://github.com/zlt2000/springs-boot-plugin-test
https://stackoverflow.com/questions/15720822/how-to-get-names-of-classes-inside-a-jar-file

The issue provides only links to a SegmentFault article, a springs-boot-plugin-test repository, and a Stack Overflow question. Start by reading those references to determine the intended hot-loading scope; the issue names no project files, tests, entry point, or completion criteria.

Written by the indexing model from the issue text.