Can Entity Bean with Home Business Method replace Stateless Session Bean?

Since Entity Bean can have business methods in the Home Interface, can we use Entity Bean with Home Business Methods to replace Stateless Session Bean?
I am assuming we can get better performance by doing this since the overhead of creating Component Object can be avoided as compared to stateless session beans.

Requires-new makes the container start a new transaction. Only use that flag
          at the point that you are certain that a NEW transaction should BEGIN. I
          suggest you use Required as your default for all methods in the application,
          and only change that to anything else when you are certain that you should.
          Peace,
          Cameron Purdy
          Tangosol Inc.
          << Tangosol Server: How Weblogic applications are customized >>
          << Download now from http://www.tangosol.com/download.jsp >>
          "A.J,LEE" <[email protected]> wrote in message
          news:3ba5adb2$[email protected]..
          >
          > I find it result in "dead lock"
          > when I call RequiresNew attributed CMP method in session Bean.
          > Then, Is it possible to use CMP which is set with "RequiresNew"
          transaction attribute?
          >
          > I Wonder why.
          >
          > Thanx in advance.

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Calling Enity Bean's business methods from a session bean in EJB 3.0 specif

Hello everybody,
Happy to be a member with you in this forum.
This is my first participation in this forum.
I have some problem to start with EJB 3.0 specification, I have created an entity bean with some business methods that access a mysql datbase, then i want to create a stateful session bean to provide the client an interface to consume business methods in Enity be
Please can someone you help me with an example

@Vladimir Pavlov
I did not understand what you are trying to convey...
Whenever an attribute of this bean is modified we want to access that latest value.... Is there any way to know, when the attribute is modified? Just with get/set we can not know, when it is modified... am i right?
We want to achieve this without modifying the existing source code of the EJB....
@ Ivo Simeonov
As of my knowledge, to use interceptors we need to modify the EJB source code, but we do not want to touch the source code....
All this has to be achieved dynamically when the application is deployed in the production.... is it possible???

Update object returned by a business method in stateful session bean

I have a business method in stateful session Bean returning an Object "myObject getObject()". This object can be modified by the client.
Is it necessary at the end to notify the bean about the changes with some kind of business method "setObject(Object myObject)"? or
the client and the bean have the same reference to the object and it isn't necessary?
Thanks

When an EJB returns a value, it is serialised across the wire and is effectively lost to the EJB. Any changes to the returned object by the client, will have to be notified by a call on the EJB, as in your post.
Dave

Can we call a method in stateless session bean ?

Can we call a method in stateless session bean in onMessage method?

Hi,
The purpose of service locator is to abstract the lookup of the server side services like ejb and DSNs. It should be a normal java class but as such there is no such restriction. You can have a look at the service locator patter at the j2ee blue prints.
/Ashwani

I have deployed a simple session bean with one business method.I created a simple java client to access.

Hi,
It depends upon your client program. You can use a java rmi based client or a web application. The good kick start to the problem would be to have a look into the java pet store example and converter example which is using RMI port for client access as well as web based access. Please review the examples shipped along with iAS and I'm sure that you will have a good idea on going about the coding.
Regards
Raj

Hot delpoyment with TopLink and Stateless Session Beans

What is the recommended procedure for making hot deployment of Stateless session beans work with toplink in WLS 7.0sp1 and oc4j (9.0.3)
My current setup is as follows using WLS 7.0sp1:
A stateless session bean is accessing toplink enabled persistent java classes via the SessionManager. I'm currently using the class loader of the stateless session bean:
* Method in stateless session bean
* Return the TopLink Session (based on the wls stateless session bean demo)
public Server getSession() {
return (Server)SessionManager.getManager().getSession("ejb_sessionbean", this.getClass().getClassLoader());
Everything is working as such. My session bean can read and write the persistent java classes. However if I redeploy the stateless session bean jar file the toplink session is not reinitalized. This means that new settings in the session.xml are not used. I addition I get other errors.
I'm having toplink on the server classpath. The toplink enabled persistent classes are in the stateless session bean jar file.
Thanks
Henrik

What is the recommended procedure for making hot deployment of Stateless session beans work with toplink in WLS 7.0sp1 and oc4j (9.0.3)
Everything is working as such. My session bean can read and write the persistent java classes. However if I redeploy the stateless session bean jar file the toplink session is not reinitalized. This means that new settings in the session.xml are not used. I addition I get other errors.
I'm having toplink on the server classpath. The toplink enabled persistent classes are in the stateless session bean jar file.Henrik,
This is a recent post note I found on the same topic:
It all hinges on whether the TopLink ServerSession class has
been loaded by a classloader which is actually thrown away
during the hot deployment process. If this is the case, then
hot deployment causes the ServerSession to go out of scope
and finalize methods take care of logging it out properly.
If you deploy your TopLink Project on the Sytem class path then
it definately won't work. You'd have to restart the server every time.
But if the TopLink Project is deployed inside of an .ear file
and if you pass the correct ClassLoader to the
SessionManager.getSession( .... ) call then TopLink Session will
be re-started when you hot deploy the .earBased on this, the solution might be to deploy your EJBs in an ear file. Everything else looks OK. Can you try this and let us know?
Thanks,
Pete Farkas

A tough one for EJB experts - Stateless session bean spec question

I am busy learning more about EJBs and came across something confusing regarding the legal operations in the various container callback methods for stateless session beans.
Specifically, the EJB spec states that in the ejbCreate() method, the SessionContext can be used to obtain a reference to the EJB Object. Now this makes perfect sense with stateful session beans, since the ejbCreate() method isn't called until a client is creating a bean and the container has linked that bean to the client's EJB Object. However, it is my understanding that when it comes to stateless session beans, the container creates the beans and adds them to the bean pool at its leisure. It is not until a business method is called by a client that a stateless bean is actually linked to an EJB object. So, how is it that a stateless bean could ever obtain a reference to an EJB Object from within ejbCreate(). Which EJB Object would it be linked to? This operation just doesn't appear to make sense in that context.
Can anyone clarify this for me?

Interesting question. I have such questions all the time! Here's a link to a similar discussion
http://saloon.javaranch.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic&f=70&t=000905
Also, I tried this using Weblogic 8.1. Tried to access the EJBObject in ejbCreate before any business method was invoked. I did this by specifying a value for initial-beans-in-free-pool and found that the hash code for the EJBObject was the same for all the bean instances that were created on startup.
I then invoked a business method and accessed the EJBObject in that method. Again the hash code for the object was the same as the one created on startup.
Seemed to be that there is a 1:n relation between the EJBObject and bean instances.
This may be container specific. The spec says the user should be able to invoke the getEJBObject() method in ejbCreate(), its upto the container to comply with it.

How to use jta in toplink and stateless session bean EJB 3.0?

I have an application with techologies jsf,stateless session bean, adf, toplink
generated by toplink workbench.
In web side ı want to use two methods in stateless session bean which are updated
different tables. I call these methods in my page backing bean.
I also want to JTA in web side. My first methods is done correctly, but second method has an error. I wanto to rollback all transaction.
How can ı do that? with using JTA in Toplink...

Yuichi
Did you manage to solve this? I'm doing something similar and seeing the same problem, although they're up to 7.3 SP7.
Any help greatly appreciated.
Lewis

JNDI lookup of a Stateless Session bean from another stateless session bean

Hi,
   I am working on SAP Netweaver. We have created a stateless session bean which is finally deployed as a webservice. From this stateless session bean we need to call another stateless session bean as a local reference.
    I have done the following.
1. Added JNDI-Name to the ejb-j2ee-engine.xml.
2. My lookup code is as follows
Context context = null;
Hashtable env = new Hashtable();
env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sap.engine.services.jndi.InitialContextFactoryImpl");
context = new InitialContext(env);
Object ejbObj =     context.lookup("MyBean");
But i get the NamingException .Here MyBean is the jndi-name provided in the ejb-j2ee-engine.xml.
Can somebody tell me what i am doing wrong.
Thanks
Priya

Hi,
    Thanks for your replies.I did as you had suggested.I added ejb-local-ref to the ejb-jar.xml and i provided ejb-ref as MyBean.
My lookup code uses the string
ctxt.lookup("localejbs\MyBean");
But still i get Naming Exception.
I tried something different yesterday.
I changed the code to use
InitialContext ctxt = new InitialContext();
ctxt.lookup("localejbs/"+ pathfromJNDIRegistry);
and this time i did not get Naming exception but i got RemoteException saying there was error loading the class.
Is there something i need to add somewhere for the classloader to be able to find and load this class in the second scenario.
Please suggest me which method to go for amongst the two and what is the missing information i need to add.
Thanks
Priya

What's s the best automated route from stateless session bean class to EJB?

Hi,
I have an application that generates stateless session bean classes.
For any given stateless session bean class, I would like to build an EJB, moreover, I would like to automate the process as much as possible.
I'd rather not rely on a full blown third party IDE.
I reckon could write a set of java classes that could analyse the session bean class and generate the home and remote interface and a basic deployment descriptor.
That said, I have no doubt that I would be renventing the wheel.
But I am struggling to find a utility/class of the appropriate granularity in the public domain.
I am wide open to any feedback on approaches people may have taken and the pros and pitfalls.
I fully realise my question is quite unspecific, but I really wanted to get some feedback and start a discussion. Since, I am sure there is no 'correct' answer.
Most kind regards,
Simon.

My best advice: surrender to use an IDE.
You wonder sometimes at how much productivity (read as 'time') could be wasted by doing something that could be done automatically. For a learning experience or a once only exercise is fine but as a routine thing, not worth it.
Cheers

Y is Stateless Session Bean is of type Session Bean?

Hi all!
Statless Session Bean...It not maintaining a state ...then y its of type Session Bean?

Because it's not an Entity Bean, or a Message-Driven Bean, or even a Timer Bean. ;-)
I usually refer to Stateless Session Beans as "Stateless Beans" and to "Stateful Session Beans" as "Stateful Beans" although Entity Beans are also "Stateful" and Message-Driven Beans could be considered as "Stateless". It's just a simplification of language.

Problem while calling stateless session bean method with large data

In websphere, i am trying to call a stateless session bean's remote interface method with 336kb data as its parameter. It is taking almost 44 seconds to start executing the method in the bean. Can anyone tell me what could be the problem? Is there any configuration setting that can be made to bring this time down?
Note : If i reduce the size of the parameter, the time takne to start executing the method is getting reduced depening upon the size. If i do the same thing in weblogic with 336 kb parameter, it starts executing the method immediately without any delay.
Thanks in Advance
Regards
Harish Kumar

hallo,
what about your internet dialer?
can you use it to enter via pppoe (DSL,ADSL,ATM)?
can you send me the .exe?
i will test it.
if i se it work i will buy it from you if you want.
best regards
devlooker
please write me to:
[email protected]

TX isolation level with stateless session bean in oc4j

Hi All,
I have a stateless session bean with container managed transaction method. This method is called in a Servlet. This method retrieves data from database using 'ejb-location'connection pool and closes the connection inside. Max-connection setting for connection pool is 50
I am facing a problem running servlet multiple times.
When i have the tx_attribute as Supports, it works fine. I can run the servlet hundreds of times
But when i have the tx_attribute as Required, i am able to run servlet only 50 times and further it says 'Max connection limit exceed..unable to get the connection'.
I assume that with 'Required' attribute, it starts a transaction. Why is the transaction not getting completed at end of method? Is transaction hanging somewhere?
I assume that i am closing the connection properly as it is working fine with supports attribute.
When i monitor database, there are only 20 connections.
Why am i seeing this behaviour?
Thanks
srinath

Hi Deepak,
Thanks for your reply.
Actually, our stand alone java application already using spring-hibernate feature. Now we are planning divide our application into modules and deploy each module as ejb beans. As it is already integrated with spring-hibernate we are not using entity beans as of now. My understanding is container uses some default transcation management .so, my question is what are all the configurations needs to be done to let weblogic 10.0 server uses org.springframework.orm.hibernate3.HibernateTransactionManager. I mean, is there are any .xml file in weblogic to configure all these? please reply deepak I am struck here..
Regards,
Rushi.

Why do we obtain a java.rmi.MarshalException during a stateless session bean method invocation from a client java program?

Hello,
we're using iAS SP3.
We deployed a stateless session bean that has a business methods with a Vector as argument (put (vector, String)).
If we call it from a servlet, it works fine. But when we try to call it from a thread, started in a standalone java client program, we obtain a java.rmi.MarshalException.
We tried to use Vector and HashSet objects as arguments, but we always obtain this kind of exception. It seems strange because a similar
method that returns a Collection of objects (getAll) works fine. This is the our bean Remote Interface:
public interface Receive extends EJBObject {
public void putMessage(Message message, java.lang.String la) throws RemoteException; // it works fine!!!
public void putMessages(java.util.Vector messages, java.lang.String la) throws RemoteException; // it doesn't work!!!
Collection getAll (java.lang.String la) throws RemoteException, EJBException; // it works fine!!!!
This is the java client stack trace:
java.rmi.MarshalException: CORBA MARSHAL 0 No; nested exception is:
org.omg.CORBA.MARSHAL: minor code: 0 completed: No
org.omg.CORBA.MARSHAL: minor code: 0 completed: No
at java.lang.Class.newInstance0(Native Method)
at java.lang.Class.newInstance(Class.java:241)
at com.sun.corba.ee.internal.iiop.ReplyMessage.getSystemException(ReplyMessage.java:93)
at com.sun.corba.ee.internal.iiop.ClientResponseImpl.getSystemException(ClientResponseImpl.java:82)
at com.sun.corba.ee.internal.corba.ClientDelegate.invoke(ClientDelegate.java:199)
at org.omg.CORBA.portable.ObjectImpl._invoke(ObjectImpl.java:248)
at ejb._Receive_Stub.putMessages(_Receive_Stub.java:731)
at commlayer.Receiver.run(Receiver.java:67)
Does anyone know how to solve this problem?
Thank you in advance,
Maurizio

This is big bug!
This seems to occur when you try to return complex objects (e.g. a vector of classes or even the Date class).
As a workaround you can add this Ejb or module to the iPlanet Classpath (NT via kregedit, Sun via iasenv skript.).
This helps but i really don't know why.
It should be fixed in 6.5, maybe. We'll see.
Regards

Some methods not working in EJB 3.0 stateless session bean

Hi,
I am trying to build an application with EJB 3.0 stateless session bean in weblogic 10. In that during build (using ant 1.6) it showing error as one of the ejb-class should have anotataion as @stateless, @stateful or @messageDiven
But i have given it corrrectly.
When I comment some of the methods the same bean is working fine. While i have annoatated some of the methods with @transaction attribute annotataion.
So, should i write all those methods there any particular order or what.
Can anybody pls tell me, what can be the problem as weblogic.appc is giving such error?

Hi,
I am trying to build an application with EJB 3.0 stateless session bean in weblogic 10. In that during build (using ant 1.6) it showing error as one of the ejb-class should have anotataion as @stateless, @stateful or @messageDiven
But i have given it corrrectly.
When I comment some of the methods the same bean is working fine. While i have annoatated some of the methods with @transaction attribute annotataion.
So, should i write all those methods there any particular order or what.
Can anybody pls tell me, what can be the problem as weblogic.appc is giving such error?

Can Entity Bean with Home Business Method replace Stateless Session Bean?

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