URLClassLoader.getResource throws undocumented IllegalArgumentException

Summary

Modify the implementation of java.net.URLClassLoader such that an undocumented IllegalArgumentException is no longer thrown from the getResource[s] and findResource[s] methods.

Problem

The javadocs for URLClassLoader.findResource(), and those inherited from ClassLoader.getResource(), indicate that null will be returned if there are problems getting a resource. However, the implementation throws an undocumented IllegalArgumentException under specific conditions (when getting a resource named with a Windows path, "c:/windows" from a URL ending in '/'). This can cause incorrect behavior (most likely on Windows systems). An example of such a problem was discovered in Spring Framework, necessitating a workaround.

Similarly, an IllegalArgumentException can occur when using Enumerations returned from findResources() and getResources().

Solution

Modify the implementation of java.net.URLClassLoader to not throw IllegalArgumentException when finding resources.

Specification

No specification changes