Screwey rmi-iiop behavior

Question

I got the rmi-iiop example code to work just fine, but I tried extending
it a little and strangeness ensues. Here's what I did:
I'm using a stock weblogic 6.0 install on solaris 8 (sparc). I added
the following new method to the Trader interface:
public void func(javax.naming.Name n) throws RemoteException;
and I added the implementation of that method to TraderBean like so:
public void func(javax.naming.Name n) {
System.out.prinltn("n [" + n + "]");
I then added a call to the new Trader function to the end of the
example() method in Client, just before the trader is removed:
try {
com.sun.jndi.ldap.LdapName lname =
new com.sun.jndi.ldap.LdapName("a=b");
trader.func(lname);
} catch (javax.naming.NamingException ne) {
ne.printStackTrace();
Then I compiled everything using the supplied build.sh, copied the
ejb_over_iiop.jar into config/mydomain/applications, and ran
startWebLogic.sh int the config/mydomain directory to start the server.
I then run the client like so (using the 1.3 java version included with
weblogic 6.0):
java -cp
/opt/bea/wlserver6.0/config/examples/clientclasses:/opt/bea/wlserver6.0/config/mydomain/applications:/opt/bea/wlserver6.0/lib/weblogic.jar
examples.rmi_iiop.ejb.rmi_iiop.Client iiop://localhost:7001
And I get the following output:
Beginning statelessSession.Client...
Creating a trader
Buying 100 shares of BEAS.
Buying 200 shares of MSFT.
Buying 300 shares of AMZN.
Buying 400 shares of HWP.
Selling 100 shares of BEAS.
Selling 200 shares of MSFT.
Selling 300 shares of AMZN.
Selling 400 shares of HWP.
There was an exception while creating and using the Trader.
This indicates that there was a problem communicating with the server:
java.rmi.RemoteException: CORBA UNKNOWN 0 No; nested exception is:
org.omg.CORBA.UNKNOWN: minor code: 0 completed: No
End statelessSession.Client...
Basically the call to the new method fails, and the server communication
error it produces doesn't provide much information. So question #1 is,
what's going on here?
And here's the really weird part: if I change the method signatures in
Trader and TraderBean so that the argument type is the concrete class
com.sun.jndi.ldap.LdapName instead of the interface javax.naming.Name
(which does extend java.io.Serializable, incidentally), it works fine!
I tried this with my own interfaces and concrete classes, and I get the
same strange behavior: calling methods with interface argument types on
the ejb via rmi-iiop fails with the above cryptic error, but methods
with concrete argument types work fine.
I also tried this out on a non-ejb rmi-iiop server object using jdk 1.3
but not weblogic. In that case both interfaces and concrete method
argument types work just fine.
Now I'm wondering if this could be a bug in weblogic.ejbc's iiop
generation. Can anyone else verify this problem?
Edwin Park
[email protected]

Answer 1

Comments in line...
Edwin Park wrote:
I got the rmi-iiop example code to work just fine, but I tried extending
it a little and strangeness ensues. Here's what I did:
I'm using a stock weblogic 6.0 install on solaris 8 (sparc). I added
the following new method to the Trader interface:
public void func(javax.naming.Name n) throws RemoteException;
and I added the implementation of that method to TraderBean like so:
public void func(javax.naming.Name n) {
System.out.prinltn("n [" + n + "]");
I then added a call to the new Trader function to the end of the
example() method in Client, just before the trader is removed:
try {
com.sun.jndi.ldap.LdapName lname =
new com.sun.jndi.ldap.LdapName("a=b");
trader.func(lname);
} catch (javax.naming.NamingException ne) {
ne.printStackTrace();
Then I compiled everything using the supplied build.sh, copied the
ejb_over_iiop.jar into config/mydomain/applications, and ran
startWebLogic.sh int the config/mydomain directory to start the server.
I then run the client like so (using the 1.3 java version included with
weblogic 6.0):
java -cp
/opt/bea/wlserver6.0/config/examples/clientclasses:/opt/bea/wlserver6.0/config/mydomain/applications:/opt/bea/wlserver6.0/lib/weblogic.jar
examples.rmi_iiop.ejb.rmi_iiop.Client iiop://localhost:7001
And I get the following output:
Beginning statelessSession.Client...
Creating a trader
Buying 100 shares of BEAS.
Buying 200 shares of MSFT.
Buying 300 shares of AMZN.
Buying 400 shares of HWP.
Selling 100 shares of BEAS.
Selling 200 shares of MSFT.
Selling 300 shares of AMZN.
Selling 400 shares of HWP.
There was an exception while creating and using the Trader.
This indicates that there was a problem communicating with the server:
java.rmi.RemoteException: CORBA UNKNOWN 0 No; nested exception is:
org.omg.CORBA.UNKNOWN: minor code: 0 completed: No
End statelessSession.Client...
Basically the call to the new method fails, and the server communication
error it produces doesn't provide much information. So question #1 is,
what's going on here?
Marshaling through the interface apparently fails. What orb are you using on the client?
>
And here's the really weird part: if I change the method signatures in
Trader and TraderBean so that the argument type is the concrete class
com.sun.jndi.ldap.LdapName instead of the interface javax.naming.Name
(which does extend java.io.Serializable, incidentally), it works fine!It appears that marshaling an interface (or abstract class) fails, but marshaling a concrete class succeeds.
>
>
I tried this with my own interfaces and concrete classes, and I get the
same strange behavior: calling methods with interface argument types on
the ejb via rmi-iiop fails with the above cryptic error, but methods
with concrete argument types work fine.
I also tried this out on a non-ejb rmi-iiop server object using jdk 1.3
but not weblogic. In that case both interfaces and concrete method
argument types work just fine.
Now I'm wondering if this could be a bug in weblogic.ejbc's iiop
generation. Can anyone else verify this problem?I'll look into this.
>
>
Edwin Park
[email protected]