OC4J class loader issues

Question

Hi,
I'm developing four JSF-Icefaces web apps. with Eclipse and OC4J as required for my customer.
I created a common classloader inside of the folder C:\oc4j_extended_101340\j2ee\home\applib in order to avoid the repetition of the inclusion of several common jars (like commons, jsf, icefaces among many others) inside the folder web-inf/lib for all these apps.
However, this approach is not working, for some reason OC4J always throws all kinds of "ClassNotFoundException" when using this common classloader, so I have to copy the bunch of jars in web-inf/lib of all apps.
What's wrong? Thanks!!!

Answer 1

Like we told you. If the code for a class changes, Java will not automatically notice and load the new version, until you start up the JVM again. If you do not want to re-start the VM, you can create a new ClassLoader (CL), and use it to load the new code for the class.
Now, the problem is, the second CL may think it has to reload many of other classes, since it has no record of loading them itself. You will end up with duplicates of many classes.
If that doesn't suit you, there is not much alternatives.
You could rename the new version of the class, which would mean you'd have to manually track down all the old versions and upgrade them ( by using the new Ctor). You'd then have to update all the references to make them point to the new object. You can make that particular job easier by making both classes (old and new) extend a common base class, or implements the same interface, and use the interface reference (i.e program to an interface).
Another less-than-perfect possibility would be to use serialization where you serialise version-marked objects and reconstitute them with new code...
Good luck.