References of objects in Java EE. Difference for remote and local interfaces?

Question

As far as I know, Java is only call-by-reference. If an entity has to go through a remote interface, can it still have a reference? Now the entity is basically in another container, how can it still have the reference of the object? In other words: Is it possible that entites that 'go through' remote interfaces are not just references, but a copy of the object (call-by-value)?

Sorry if that is a silly idea, but the whole call-by-reference (or pass by refrence?) concept is confusing me in Java EE.

EDIT: In other words: Are objects from session beans ALWAYS passed as a reference?

Answer 1

Java is always a call-by-value. Here is the example which will make things clear:

class Operation{  
int data=50;  

void change(int data){  
  data=data+100;//changes will be in the local variable only  
}  

public static void main(String args[]){  
  Operation op=new Operation();  
  System.out.println("before change "+op.data);  
  op.change(500);  
  System.out.println("after change "+op.data);   

}
}

Output:before change 50
       after change 50