Internals of Java Class Loading

This article starts from the basics, such as the difference between code and data, and how they are related to form an instance or object. Then it looks into the mechanism of loading code into the JVM with the help of class loaders, and the main type of class loaders available in Java. The article then looks into the internals of class loaders, where we cover using the basic algorithm (or probing), followed by class loaders before it loads a class. The next section of the article uses code examples to demonstrate the necessity for developers to extend and develop their own class loaders. This is followed by explanation on writing your own class loaders and how to use them to make a generic task-execution engine that can be used to load the code supplied by any remote client, define it in the JVM, and instantiate and then execute it. The article concludes with references to J2EE-specific components where custom class loading schemas becomes the norm.

Click the link to read: http://www.onjava.com/pub/a/onjava/2005/01/26/classloading.html?page=1