Component Development for the Java™ Platform

2.8. Debugging Class Loading

The flexibility of the class loader architecture creates the potential for extreme confusion when something goes wrong. Consider the simple situation of an application failing with a ClassNotFoundError for class Foo. This could be caused by the Foo.class file being in the wrong directory, by an incorrect –cp parameter on the command line, by a problem with the CLASSPATH environment variable, or by any of the bootclasspath or extensions path settings. Even worse, the failure to load Foo could be the result of a chain reaction caused by some other class Quux being loaded from an unexpected location. Once Quux is loaded, all of the classes that Quux references are implicitly loaded from Quux's class loader delegation, ...