krishna prasad gunasekaran

hi anyone on this?

Hi,
container calls an ejbStore() method on an entity bean instance during a business method call transaction. But why does this happen during even a fetch transaction(calling a getter method, which is not going to change entity bean). Does the real entity needs to be updated even when the client has not updated the entity bean?

Hi,
they both look a bit similar in the way they carry out the job. Like traversing through the component they compose which happens to extend the same interface.
The difference being CP is more of a tree while DP is like a chain with new bahaviors added on the way. somehow they look similar in certain ways. Do they?
My doubt with CP is that how it works in case of Objects of different kind?

Well thanks, but i have another one for you..
Struts say they use Command Pattern calling Action's execute() method. But i couldn't come around the explanation that a very basic simple use of inheritance and polymorphism can be called a pattern instead of a programming idiom. I mean, all request processor does is action.execute(), which by the way, just uses an interface reference to call the method. This is so very basic programming technique. can this be called Command Pattern.
Command Pattern, as far as i have understood, achieves complete decoupling of Invoker and Receiver. Meaning, the Invoker can invoke any Object, not just implementations of Action. All it care is to call Comamnd's execute(), which does the rest. But in struts this isn't the case, i guess.

Jelle Klap wrote:A Command doesn't have to be specific to one concrete Receiver implementation, either.

You mean that there can exist an implementation of a Command which has reference NOT to one concrete Receiver implementation but to it's interface. By progamming to an interface we can decouple Command and Receiver and a chance to call multiple Receiver implementations.
But on the other hand, the Reveiver implementations needn't be similar at all, they can be completely two different objects with different behaviors. In this case we cannot program to an interface and need to have two different Command implementations.
Am I right here?

Hi,
Are we going to have a specific Command for each Receiver(Action).

i want the complete list of jndi binding in my Websphere server on my unix system. How to find them.

what is the name of the context under which ejb bindings are present in JBOSS.?
to put it simply, what is that i should supply to listBindings() method of InitialContext?

i tried with context.listBindings(), but NameNotFoundException is thrown.

I read in a book

"All networking code you write is applied to interfaces, not implementations. In fact, you must use this paradigm in RMI-IIOP—you do not have a choice. It is
impossible to perform a remote invocation directly on an object implementation. You can operate solely on the interface to that object’s class."

Why is that we can do it with interface and not with it's object implementation? actually, under the interface lies the actual Object Implementation object which we make invocations on. then why is that we claim we can't make invocation on implementations?

Hope you understand my question

why it is impossible to perform a remote invocation directly on an object implementation?

What exactly do you mean by servletness??

Let's leave the idea bout Servletness.
Constructor makes only an Object not Servlet. then what makes servlet? ServletConfig?

What do you mean by "call an object"??

can we say an object that's not a subclass of Servlet but has a ServletConfig as servlet?

1) Why an object having declared itself servlet by extending Servlet, don't have that servletness immediately after it's creation and have to wait for container to call it's init() method to get that servletness?

2) If ServletConfig can give you the servletness, what is the need for us to extend Servlet?

3) can we call an object that's not a subclass of Servlet but has a ServletConfig as servlet?

i mistyped it. i meant to say "java:comp" only. i configured my jboss in eclipse. i start my jboss from eclipse. then why is it not bound.

i don't start jboss with run.bat. i use eclipse IDE. i have configured my jboss in eclipse. i start jboss from eclipse. i haven't set JAVA_HOME in my eclipse jboss server. i have set it as environment variable.

context.listBindings("java.comp") throws the following exception

javax.naming.NameNotFoundException: comp not bound at org.jnp.server.NamingServer.getBinding(NamingServer.java:491) at org.jnp.server.NamingServer.getBinding(NamingServer.java:499) at org.jnp.server.NamingServer.getObject(NamingServer.java:505) at org.jnp.server.NamingServer.listBindings(NamingServer.java:367) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:615) at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:309) at sun.rmi.transport.Transport$1.run(Transport.java:168) at java.security.AccessController.doPrivileged(AccessController.java:274) at sun.rmi.transport.Transport.serviceCall(Transport.java:164) at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:506) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.handleRequest(TCPTransport.java:838) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:912) at java.lang.Thread.run(Thread.java:797) at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:263) at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:239) at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:141) at org.jnp.server.NamingServer_Stub.listBindings(Unknown Source) at org.jnp.interfaces.NamingContext.listBindings(NamingContext.java:772) at org.jnp.interfaces.NamingContext.listBindings(NamingContext.java:757) at javax.naming.InitialContext.listBindings(InitialContext.java:418) at com.test.EntityTest.main(EntityTest.java)

when i invoked listXML() method in service JNDIView in jmx-console, it displayed the following, which proved the presence of java:comp.

null java:comp MyEntityEJB env org.jnp.interfaces.NamingContext java:comp MyCMPBean env org.jnp.interfaces.NamingContext java: SecurityProxyFactory org.jboss.security.SubjectSecurityProxyFactory DefaultJMSProvider org.jboss.jms.jndi.JNDIProviderAdapter comp javax.naming.Context JmsXA org.jboss.resource.adapter.jms.JmsConnectionFactoryImpl jaas javax.naming.Context JmsXARealm org.jboss.security.plugins.SecurityDomainContext timedCacheFactory javax.naming.Context Failed to list contents of: timedCacheFactory, errmsg=org.jboss.util.TimedCachePolicy incompatible with javax.naming.NamingEnumeration TransactionPropagationContextExporter org.jboss.tm.TransactionPropagationContextFactory StdJMSPool org.jboss.jms.asf.StdServerSessionPoolFactory Mail javax.mail.Session TransactionPropagationContextImporter org.jboss.tm.TransactionPropagationContextImporter TransactionManager org.jboss.tm.TxManager Global UIL2ConnectionFactory ConnectionFactory javax.naming.LinkRef UserTransactionSessionFactory $Proxy11 console org.jnp.interfaces.NamingContext PluginManager $Proxy36 UIL2XAConnectionFactory XAConnectionFactory javax.naming.LinkRef UUIDKeyGeneratorFactory org.jboss.ejb.plugins.keygenerator.uuid.UUIDKeyGeneratorFactory MyEntityEJB $Proxy45 UserTransaction org.jboss.tm.usertx.client.ClientUserTransaction MyCMPBean $Proxy47 jmx org.jnp.interfaces.NamingContext invoker org.jnp.interfaces.NamingContext RMIAdaptor $Proxy35 rmi org.jnp.interfaces.NamingContext RMIAdaptor jmx/invoker/RMIAdaptor javax.naming.LinkRef UILXAConnectionFactory XAConnectionFactory javax.naming.LinkRef UILConnectionFactory ConnectionFactory javax.naming.LinkRef

then how listBindings threw that exception?