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

Similar Messages

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.

Calling EJB 3.0 Stateless Session Bean

Dear all,
I created a stateless session bean with a hello world method on it. Now i want to call the method from a BeanDecorator class, through a getter metod. When i use the jndi lookup in my getter, i can call the helloWorld method without a problem. However, when i dont use the jndi lookup, and only use the @EJB annotation, i always get a nullpointer.
This is working:
InitialContext ic = new InitialContext();
test = (TestLocal)ic.lookup("test.be/ear~bd/LOCAL/TestBean/"+TestLocal.class.getName());
test.helloWorld()
This gives nullpointer:
@EJB
private TestLocal test;
test.helloWorld();
What is the correct way to consume session beans without having to explicitly code the jndi lookup?
Kind regards.

Hi,
any annotation like this can be used only in "managed classes" like Session Beans, Servlets etc. Managed classes are those classes managed by the J2EE server. Managed here means, lifetime controlled by server.
You can find this in J2EE specification.
Frank

Can we implement "Service Locator" in Stateless Session Bean??

Hi,
My enterprise application is using Stateless Session Bean. To increase the performace , I think of implementing "service Locator" pattern so as to cache the EJBHome objects in order to avoid looking up Home object every time. I want to know whether this will work out in case of stateless session bean??
Thanks for ur help.

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

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

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.

Remove on stateless session bean

Will failing to call remove on a stateless session bean cause it to be
passivated rather then removed when it is no longer used? I have read
for a statefull bean failing to remove a bean can cause a peformance
hit since passivate takes a bigger system resource hit over remove.
Jeff

No, remove() on stateless session bean doesn't do anything.
Jeffrey Ellin <[email protected]> wrote:
Will failing to call remove on a stateless session bean cause it to be
passivated rather then removed when it is no longer used? I have read
for a statefull bean failing to remove a bean can cause a peformance
hit since passivate takes a bigger system resource hit over remove.
Jeff--
Dimitri

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]

Call stateless session bean EJB 2.0 from Webdynpro Java UI

Hello,
Can someone please tell me asto how to call a stateless session bean EJB 2.0 from Webdynpro Java UI?
The NWDS version is 7.0.
Thanks and Regards,
Arya

Hi Aryadipta
Please check this pdfs
https://www.sdn.sap.com/irj/scn/index?rid=/library/uuid/b00917dc-ead4-2910-3ebb-b0a63e49ef10&overridelayout=true
Steps for calling stateless session bean in Webdynpro java
Go to NWDS -> open perspective ->j2ee
select EJB Module Project ->create a project with name
Open the Project -->RC on ejb-jar.xml -> Select new --> EJB
Give name to EJB Bean (First letter should be in capital letters)
select the type of bean as Stateless session bean and give the package name to store that EJB bean.
After that Expand ejb-jar.xml and then select the <projectEJB>
Double click on this on method tab double click you will get business method where we will create the methods for business logic
Double click on projectEJB and then RC on bean tab and write required business logic in bean window as follows(based on requirement we will design a business logic).
After writing the business logic go to project -> rebuild
Till now we have created one EJB jar file
then go to File-->Enterprise Application Project -->create a project (projectEAR)
After creating a project click on next-> here we will have ear projects and then we select specific project required for our application.(here select projectEJB)
After that Calculate EAR project will be available on j2ee explorer.
Right click on <Bean> here
select New->Web Service->give a name to webservice and select Default configuration type as simple SOAP
-->click next -> Finish.
That webservice and related are created in ejb-jar.xml .
Expand the ejb-jar.xml.and double click on < webservice>
RC ProjectEJB -> Build EJB Archive RC on CalculateEAR ->Build applicationarchive.
Expand the projectEAR->RC on CalculateEAR.ear->Deploy to J2EE Engine
Double click on calculateEAR.ear ->Webservice navigator tab ->we eill servers expand the node
select the specific WebService
Here we test the webservice by click on Test and test it.
After that go to Web dynpro perspective ->create one webdynpro Project and one component
RC on model> Select import Web Service model(last)>give model name and package
and select radio button as local file system or URL
Go to WSnavigator->copy the WSDL path and paste it in model WSDL path and click on finish.
from here onwards steps are same as that adaptive RFC model
Hope it helps
Thanks
Tulasi Palnati
Edited by: Tulasi Palnati on Aug 26, 2009 12:15 PM
Edited by: Tulasi Palnati on Aug 26, 2009 12:43 PM

Stateless Session Bean has no Context when called from WAR

Hello,
Here is the code for my stateless session bean (it will carry out certain actions based on the timer service)
package DigestTest;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.util.Date;
import javax.ejb.*;
import javax.ejb.TimedObject;
import javax.ejb.Timer;
* This is the bean class for the MasterTimerBean enterprise bean.
* Created Sep 7, 2006 9:05:09 AM
* @author ttaylor
public class MasterTimerBean implements SessionBean, MasterTimerRemoteBusiness, MasterTimerLocalBusiness, TimedObject
private SessionContext context;
public void setSessionContext(SessionContext aContext)
context = aContext;
* @see javax.ejb.SessionBean#ejbActivate()
public void ejbActivate()
* @see javax.ejb.SessionBean#ejbPassivate()
public void ejbPassivate()
* @see javax.ejb.SessionBean#ejbRemove()
public void ejbRemove()
// </editor-fold>
* See section 7.10.3 of the EJB 2.0 specification
* See section 7.11.3 of the EJB 2.1 specification
public void ejbCreate()
// TODO implement ejbCreate if necessary, acquire resources
// This method has access to the JNDI context so resource aquisition
// spanning all methods can be performed here such as home interfaces
// and data sources.
public void ejbTimeout(Timer timer)
try
BufferedWriter writer = new BufferedWriter(new FileWriter("C:\\timerTest.txt"));
writer.write("Timer has tripped");
writer.newLine();
writer.flush();
writer.close();
catch(Exception e)
return;
// Add business logic below. (Right-click in editor and choose
// "EJB Methods > Add Business Method" or "Web Service > Add Operation")
public String initializeTimer()
String result = "\n\nInitializing Timer\n";
try
// Create Your Timer
if(context!=null)
TimerService ts = context.getTimerService();
result = result+"Instantiating Timer Object\n";
Timer timer = ts.createTimer(new Date(), 5000, "TestTimer");
result = result+"About to grab TimerHandle";
TimerHandle timerHandle = timer.getHandle();
else
result = result+"\nContext Object is null\n";
catch (Exception e)
result = result+"\nError:\n"+e.toString();
return result;
public String writerTest()
String result = "about to write";
try
result = result+"\nOpening the file";
BufferedWriter writer = new BufferedWriter(new FileWriter("C:\\timerTest.txt"));
result = result+"\nWriter Test Passed";
writer.write("Writer Works");
writer.newLine();
result = result+"\nFlushing writer";
writer.flush();
result = result+"\nClosing writer";
writer.close();
catch (Exception e)
result = result+"\n"+e.toString();
return result;
I am calling initializeTimer() from a jsp page with a simple <jsp:useBean tag>.
The program keeps returning that the context variable is not set(this is from the context!=null conditional in initializeTimer()). I am very confused, I thought that setContext(...) was called by the container upon instantiation (and thus should happen completely without any action from me).
How am I able to call a session bean that has not had the context set?
Any information is appreciated,
Thanks,
Scott

thank you for your reply, rajeevm007.
it seems that the question is really a problem now.
i think i should update weblogic to the lastest version and confirm this question. if it still in there, it seems that we have to reset the global variables all manually. so, now, we are discussing that should we modify all the ejbs, or wait the next version of weblogic. :) of cause the second choice is a joke.
no other good choice?
maybe in the march of the next year....
cheers
thank you again.

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?

Stateless Session Bean calling another Stateless Session Bean

Hi all,
I have written 2 Stateless Session bean and would like to call the business method of 2nd Stateless Session Bean in the business method of the 1st.
I have written the lookup code for 2nd SB in the business method of 1st SB and would like to execute the business method in the same method itself.
What do I have to do for the same for the following :
Deployment Descriptor file or any other file needs to be modified.
I am using Weblogic 6.1 and SQL Server 7.0 as database.
Thanks in advance,
Seetesh

This is actually quite similar to calling a session bean from anywhere.
Try this
//Session Bean 2 - Business Method, JNDI name SessionBean2
public void doSomethingMore(String what)
// Session Bean 1 which call.
public void doSomething()
   InitialContext initCtx = new InitialContext();
   SessionBean2Home home2 = null;
   SessionBean2 bean2 = null;
   try
     home2 = (SessionBean2Home)initCtx.lookup("SessionBean2");
     bean2 = home2.create();
   }catch(FinderException ex){..}
    catch(CreateExceptrion ex){..}
   try
     bean2.doSomethingMore("Anything");
   }catch(remoteException ex){..}
}In my case (webLogic 5.1) I did not need to change anything in any of the deployment descriptor. However, both beans needs top be deployed on same instance of Application server (might work across instances but didnt try)
This should do it.
Amitabh

Calling Stateless Session bean from Servlet

Dear Friends,
A help will be Appreciated...
I created a EJB (Stateless Session Bean) using WebSphere Application Developer with its Business logic in Main bean. Its working perfectly fine using UTC (Standalone Test Client). But when i use a servlet to communicate with this EJB, its giving me error as follows:
Error Stack:
java.lang.NoClassDefFoundError: package name/DemoHome
at java.lang.Class.newInstance0(Native Method)
at java.lang.Class.newInstance(Class.java:254)
at java.beans.Beans.instantiate(Beans.java:213)
at java.beans.Beans.instantiate(Beans.java:57)
at com.ibm.servlet.engine.webapp.WebAppServletManager.loadServlet(WebAppServletManager.java:148)
at com.ibm.servlet.engine.webapp.WebAppServletManager.getServletReference(WebAppServletManager.java:287)
at com.ibm.servlet.engine.webapp.WebApp.getServletReference(WebApp.java:354)
at com.ibm.servlet.engine.webapp.WebAppRequestDispatcherInfo.calculateInfo(WebAppRequestDispatcherInfo.java:167)
at com.ibm.servlet.engine.webapp.WebAppRequestDispatcherInfo.<init>(WebAppRequestDispatcherInfo.java:51)
at com.ibm.servlet.engine.webapp.WebApp.getRequestDispatcher(WebApp.java:1145)
at com.ibm.servlet.engine.srt.WebAppInvoker.handleInvocationHook(WebAppInvoker.java:179)
at com.ibm.servlet.engine.invocation.CachedInvocation.handleInvocation(CachedInvocation.java:67)
at com.ibm.servlet.engine.srp.ServletRequestProcessor.dispatchByURI(ServletRequestProcessor.java:122)
at com.ibm.servlet.engine.oselistener.OSEListenerDispatcher.service(OSEListener.java:315)
at com.ibm.servlet.engine.http11.HttpConnection.handleRequest(HttpConnection.java:60)
at com.ibm.ws.http.HttpConnection.readAndHandleRequest(HttpConnection.java:323)
at com.ibm.ws.http.HttpConnection.run(HttpConnection.java:252)
at com.ibm.ws.util.CachedThread.run(ThreadPool.java:122)
For more Info let me provide the snipets of how i used the Sevlet:
Client.java
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import packagename.*; //package name of imported ear file which is in
//classpath
public class Client extends HttpServlet {
public void doGet(
javax.servlet.http.HttpServletRequest request,
javax.servlet.http.HttpServletResponse response)
throws javax.servlet.ServletException, java.io.IOException {
PrintWriter out=response.getWriter();
Properties p = new Properties();
p.put(javax.naming.Context.PROVIDER_URL, "iiop:///");
p.put(javax.naming.Context.INITIAL_CONTEXT_FACTORY,"com.ibm.websphere.naming.WsnInitialContextFactory");
try {
InitialContext initial = new InitialContext(p);
Object objref = initial.lookup("JDemo");
DemoHome home = (DemoHome)PortableRemoteObject.narrow(objref,DemoHome.class);
Demo demo = home.create();
int r=demo.testBean(4);
out.println("EJB RESULT= "+r);
} catch (Exception ex) {
System.err.println("Caught an unexpected exception!");
ex.printStackTrace();
Kindly provide ur solution to this problem. Urgent solution will be helpful as its a part of our present project.
Thanking you for ur esteemed help.
regards,
Arun.

Perhaps you webserver can't see your package jar file.
Try putting it in WEB-INF\lib directory of your app and restart your server.

Can we call a method in stateless session bean ?

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