Speaker Deck

Everything you need to know about Java Classloaders [Spring IO Barcelona 2015]

by Oleg Šelajev

Published April 30, 2015 in Programming

Classloaders: a New Hope.

In the session, we’ll get into a wonderful world where we control exactly where from and what classes does the JVM load. We will design a powerful plugin system that carefully balances flexibility and simplicity. We’ll define classes from bytes, from urls, even from a photo of a rabbit.

But the path to mastery is not a walk in the park. We’ll find mean exception, then even meaner exceptions. Then exceptions whose message doesn’t fit on the screen and is undecipherable. We’ll have to debug everything, challenge assumptions and show that your will is stronger than the soulless stubborness of Tomcat’s classloading scheme.

This session covers the basic functionality and principles of work of Java Classloaders and goes through a series of real world examples to teach how to treat the common issues that custom classloading can create.