Taxonomy of class loader problems with Jakarta Commons Logging

Taxonomy of class loader problems with Jakarta Commons Logging: "Class loading problems encountered when using JCL fall into three main categories:

Type-I: A java.lang.NoClassDefFoundError thrown when a class is inaccessible from a parent class loader even if the said class is available to a child class loader
Type-II: Assignment incompatibility of two classes loaded by distinct class loaders, even in case where the two classes are bit-wise identical.
Type-III: Holding references to a given class loader will prevent the resources loaded by that class loader from being garbage collected.
At least on a superficial level, Type-I problems are relatively easy to understand whereas Type-II problems are a bit harder to grasp at first glance. Consequently, we will start by illustrating problems of Type-I. Given their different nature, Type-III problems will be discussed only briefly towards the end of this document."

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