具有相同名称的两个相同类之间的Java差异

Question

I have a class A:

public class A implements I {}

Interface I is a class coming from a jar dependency.
I can compile this code to a jar without any compilation issues.
I deployed the jar file on our server so that an application can use it. The application runs the following code

I instance = (I) someObject.getImplementationViaJNDI();

The method uses JNDI and RMI to get an instance of my interface implementation and then throws a java.lang.ClassCastException my.domain.name.A cannot be cast to my.differentdomain.name.I
I am pretty sure the problem does not lie within JNDI or RMI because the application logs all the implemented methods of my class and the name, however it also logs the following

Object my.domain.name.A implements interface: java.lang.Class

The application that tries to cast my implementation has a version of the jar file containing Interface I on its classpath, however it does not recognize that it is implemented by class A .

I wonder how java differentiates between two identical classes with the same fqdn and how the application gets to think my class implements interface java.lang.Class .

Answer 1

Thanks to @Jens I found the solution to my problem.
The jar file I generated has all the dependencies packed within itself, including the package with the interface.
The application which loads my jar file has the interface already loaded. But then while my jar file is being loaded, it loads the interface again, but with another classloader.
I solved the error by not packing the interface in my jar so that it started using the interface class already loaded by the loading application.