Getting class cast exception where both classes are exactly the same

I am doing a JBoss SEAM project and when I view a form I get this error.

java.lang.ClassCastException:
it.cogitoweb.csi.entity.csiorelav.CsiTipoLav cannot be cast to
it.cogitoweb.csi.entity.csiorelav.CsiTipoLav

Its alway the same JPA class which is related to the form which is shown on the screen, it doesn't make sense to me why is it the same class, it seems impossible.

This happens when two different ClassLoader objects load classes with the same name. The equality of two classes in Java depends on the fully qualified name and the class loader that loaded it.

So if two independent class loaders load classes from the same location, then objects of those types will not be able to be cast to each others type, even if their classes are called the same.

As Joachim explained earlier, java.lang.ClassCastException typically occurs when two classloaders load the classes with the same name. However, i have come across another situation when this could occur.

This could occur with some IDE's that automatically reloads classes that have been modified. In such cases there might be older versions of the class retained in memory causing ClassCastException.

Here are a few ways you could resolve this issue :

1. If you are writing a custom class loader, while loading a class make sure that the base/default class loader does not already have an instance of that class loaded.

2. Make the class being loaded a sub-class of the class that is already loaded by the default class loader.

3. Make the class being loaded implement an interface that is already loaded by the default class loader.

More info here - http://www.jspwiki.org/wiki/A2AClassCastException