Getting class cast exception where both classes are exactly the same

java classcastexception
Phil picture Phil · Mar 3, 2010 · Viewed 26.2k times · Source

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.

Answer

Joachim Sauer picture Joachim Sauer · Mar 3, 2010

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.

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