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Book error or not ?? Client calls remove() on a bean that's already been removed.

 
Dean Fredericks
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Ok. Confusion.

In headfirst EJB, page 559:

Client scenarios:

(What happens when) Client calls remove() on a bean that's already been removed:

(Answer): "...Remember, remove() is just another method in the bean's interface, and if you call it on a removed bean, you'll get the same exception you'd see if you called any other business method on a removed bean - remote clients get a RemoteException, local client get EJBException"

Ok im think that statement is WRONG. But im sure i just have a bug in my understanding, please could somebody set me straight.

Now - when a client calls a method on a bean that has been removed you get a
"java.rmi.NoSuchObjectExecption"
I have written code to test that and found it to be the case.

Then i tried another test. I called remove on an object twice - to try and remove and object which had been removed. And guess what exception i got - the same as a business method ( like the explaination form the book says ), but thats a "java.rmi.NoSuchObjectExecption", NOT a RemoteException !!!

The book is wrong right ?? they have miss printed right ??? Or have I gone MAD !!!

Thanks for you time guys !!
[ December 13, 2004: Message edited by: Dean Fredericks ]
 
Grand Puba
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java.rmi.NoSuchObjectException is a subclass of java.rmi.RemoteException which gives the client some more information 'bout what's going on on the server.
If the client receives the java.rmi.RemoteException or the javax.ejb.EJBException from a method invocation, the client, in general, does not know if the enterprise Bean�s method has been completed or not.

Greetz,
Puba
 
Dean Fredericks
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Thanks for trying to reply puba, however i dont think ur answer satifies my question. Yes i relise the the once exception is a subclass of the other, but the fact is a "java.rmi.NoSuchObjectExecption", while the book says its a
"RemoteException".


I want to know why my finding are inaccurate, or if the book is wrong.
 
Adrian Fuckabee
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EJB 2.0 Spec -
18.3.5 Non-existing session object
If a client makes a call to a session object that has been removed, the Container should throw the
java.rmi.NoSuchObjectException (Subclass of java.rmi.RemoteException)
to a remote client, or the javax.ejb.NoSuchObjectLocalException (Subclass of EJBException) to a local client.

>Then i tried another test. I called remove on an object twice - to try and remove and object which had been
>removed. And guess what exception i got - the same as a business method ( like the explaination form the book says )
> , but thats a "java.rmi.NoSuchObjectExecption", NOT a RemoteException !!!

Just remember inheritance ... Dog IS AN Animal!
java.rmi.NoSuchObjectExecption IS A RemoteException!
[ December 13, 2004: Message edited by: Adrian F ]
 
Dean Fredericks
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I dont seem to be getting the responces I was hoping for in this post.

U guys so far have pointed out the ovious that "java.rmi.NoSuchObjectExecption" is a subclass of RemoteException. Yes i know that thats easy.

WHY DOES THE BOOK SAY A REMOTEEXCEPTION IS THROWN WHEN REALLY A "java.rmi.NoSuchObjectExecption" IS THROWN <---- SURELY THAT IS A BOOK ERROR.

As Adrian F has pointed out - the spec says
EJB 2.0 Spec -
18.3.5 Non-existing session object
If a client makes a call to a session object that has been removed, the Container should throw the
java.rmi.NoSuchObjectException (Subclass of java.rmi.RemoteException)


SURELEY THE BOOK IS WRONG IF THE SPEC SAYS IT SHOULD be a java.rmi.NoSuchObjectException.
 
Vagner Freitas
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Hi All,

I agree with Dean.
I have been very confused with the statement of HFEJB.
Why did not they say "NoSuchObjectException" insted of saying "RemoteException.?

Vagner
 
Adrian Fuckabee
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HFEJB p550 has a block of text that mentions that the client might NOT get the most specific exception!

It appears that which Exception the client gets depends on the container.
 
Shiang Wang
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Dean, I suggest you file an errata in this website.
http://www.oreilly.com/catalog/hfjejb/errata/

Shiang
 
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