How to get stateful and stateless session bean in second jsp

I create stateful session bean in the first jsp, then how can I get the stateful session bean in the second jsp? I find that somebody store the bean in HttpSession.
If I store the stateful session bean in HttpSession, then I can get it in the second jsp. My problem is that I can store the stateless session bean in HttpSession, and get it in the second jsp. Then, both stateful and stateless can maintain the state in the second jsp. What is the difference between stateful and stateless session bean in this case ?
I understand the definition of stateful and stateless session bean, but I'm confuse how to use session bean. Can anyone provide sample jsp to show difference of stateful and stateless? How the stateful session bean can maintain the state for the client?

Greetings,
I create stateful session bean in the first jsp, then how can I get the stateful session bean in the
second jsp? I find that somebody store the bean in HttpSession.Which is the correct scope for sharing client-specific data when 'request' scope is insufficient.
If I store the stateful session bean in HttpSession, then I can get it in the second jsp. My problem is
that I can store the stateless session bean in HttpSession, and get it in the second jsp. Then, bothWhy is that a "problem"? Does your application not require the stateless bean to be shared? If so, then don't store the EJBObject reference in the session...
stateful and stateless can maintain the state in the second jsp. What is the difference betweenWhat do you mean by this exactly?..
stateful and stateless session bean in this case ?Statefulness of session beans is in regard to maintaining client state (er, in all cases). If your "stateless" bean is receiving information from the client (i.e. its caller) - either through a create method or a business method - and that information is available (retrievable from the bean) on subsequent method calls, then that bean is, in fact, stateful - regardless of how it is deployed.
I understand the definition of stateful and stateless session bean, but I'm confuse how to use
session bean.The correct question, it here seems, is "when" to use which type... Use a "stateful" bean when information about (from) the client (i.e. the caller) must be maintained across method calls of the bean. Use a "stateless" bean for general business methods that do not depend on "prior knowledge" of the client (i.e. the caller).
Can anyone provide sample jsp to show difference of stateful and stateless? How the statefulA "sample JSP" would yield nothing additional... The semantics of calling, using, and "persisting", bean references are always the same - regardless of type or class. However, the reason(s) for using one over the other depends entirely on the needs of your application.
session bean can maintain the state for the client?I recommend that you spend more time learning about EJBs generally. In particular, it seems you require more fundamental understanding of their scope and lifecycle. Refer to sections 4, 6, and 7 of the EJB 2.0 Specification.
Regards,
Tony "Vee Schade" Cook

Similar Messages

Difference between stateful and stateless session beans

can any body explain simply what is the difference between stateful and stateless session beans? also in what kind of situations we can use these.

Hi
This is the classificatio os Session Bean.
(1) Statfull
(2) Stateless
Stateful means u will persists the state of the object.
USESE:
In a Banking system u can use the statful session just for maintaing the
state.
(2) STATELESS: that's mean u do't want to persists any state of the object. that's mean a single Request is coming ,do the desire and give the output.
EX: A Credit Card System is the Example of Stateless.
May it will helpfull to understands u. if any need write here
saM

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.
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WLS10 and Stateless Session Bean

I tried to create EJB3 application example.
1. Created Stateless Session Bean that implements Remote and Local interfaces:
Session Bean code:
package com.session;
import javax.ejb.Local;
import javax.ejb.Remote;
import javax.ejb.Stateless;
import javax.ejb.TransactionAttribute;
import javax.ejb.TransactionAttributeType;
@Stateless(mappedName="SessionBeanService")
@Remote(ISessionBeanRemote.class)
@Local(ISessionBeanLocal.class)
@TransactionAttribute(TransactionAttributeType.REQUIRED)
public class SessionBean implements ISessionBeanLocal,
ISessionBeanRemote
public String reply(){
return "MySessionBean - success !!!";
Remote Interface code :
package com.session;
public interface ISessionBeanRemote
public String reply();
Local Interface code:
package com.session;
public interface ISessionBeanLocal
public String reply();
application.xml:
<?xml version="1.0" encoding="UTF-8"?>
<application xmlns="http://java.sun.com/xml/ns/javaee"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
          http://java.sun.com/xml/ns/javaee/application_5.xsd"
     version="5">
     <display-name>EJB3 Sample Application</display-name>
     <module>
     <ejb>beans.jar</ejb>
     </module>
</application>
weblogic-application.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE weblogic-application PUBLIC
     "-//BEA Systems, Inc.//DTD WebLogic Application 8.1.0//EN"
     "http://www.bea.com/ns/weblogic/90/weblogic-application.xsd">
<weblogic-application>
          <classloader-structure>
               <module-ref>
                    <module-uri>beans.jar</module-uri>
               </module-ref>
          </classloader-structure>
</weblogic-application>
2. I packaged classes into EAR file and deployed to WLS10.
I didn't include any weblogic specific XML descriptors besides weblogic-application.jar.
My client code lookes as follows:
public void test(){
Context context = getMyServerContext();
// THIS JNDI NAME I SEE ON MY SERVER JNDI TREE
String jndiName = "sessionbeansbeans_jarSessionBean_ISessionBeanRemote";
Object obj;
obj = context.lookup(jndiName);
System.out.println(" obj class : " + obj.getClass().getName());
ISessionBeanRemote remote = (ISessionBeanRemote) PortableRemoteObject.narrow(
obj, ISessionBeanRemote.class );
String res = remote.reply();
System.out.println("res : "+res);
I get an Exception:
Exception occurred!
java.lang.ClassCastException: Cannot narrow remote object to com.session.ISessionBeanRemote
     at weblogic.iiop.PortableRemoteObjectDelegateImpl.narrow(PortableRemoteObjectDelegateImpl.java:242)
     at javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:137)
     at ca.cgi.mvest.test.server.wms.GlFacadeTest.runTest(GlFacadeTest.java:91)
     at ca.cgi.mvest.test.server.wms.GlFacadeTest.<init>(GlFacadeTest.java:53)
     at ca.cgi.mvest.test.server.wms.GlFacadeTest.main(GlFacadeTest.java:151)
java.lang.ClassCastException: Cannot narrow remote object to com.session.ISessionBeanRemote
My server console have the following output:
Root cause of ServletException.java.lang.NoClassDefFoundError: com/session/SessionBean_7pp7ls_ISessionBeanRemot
eIntf
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:12
4)
at weblogic.utils.classloaders.GenericClassLoader.defineClass(GenericCla
ssLoader.java:338)
at weblogic.utils.classloaders.GenericClassLoader.findLocalClass(Generic
ClassLoader.java:291)
Truncated. see log file for complete stacktrace
Server logs a problem already on the line when I do lookup
on JNDI name even before narrow();
It looks like my EAR was missing something. But server never complained during deployment.
May be someone can direct me to a real sample of Weblogic10-ejb3.0 application, since examples that come with WLS 10 intallation combersome and do not follow
docmentation.
Thanks in advance for any suggestion.

Hello Freind
The main different b\w stateful and statless is that stateful maintain state of method conversation means it has record that which method call before this method
but in case of stateless conversation state does not saved second different we can say that create method in stateless having no parameter but statefull having parameter I think u can understand easily
With Best Regards
Rajesh Pandey
email :[email protected]
url :-- http://www.sixthquadrant.com
Mob :-- 9811903737
Delhi India

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

JCo 3.0 Server and Stateless Session Bean

Hello,
I use JCO (3.0) and I need to integrate SAP with JBoss.
The SAP Module is calling EJB-Services over JCo.
How would the architectur looks like?
I start with using an MBean to start and stob the native JCO-Server over JMX.
This still works.
But it doesn't work:
The Client(SAP) calls the JCoServer (works fine).
But the call off the EJB failed.
What solutions do you have to share?
Do you use a stateless session bean?
Best regards
Peter

The program ID should be with length 8 max

Newbie: How do i use a stateless session bean in a backing bean?

I have a stateless session bean with a function 'getVoterList()'; how do i instantiate the bean and use it in from my managed bean?
I dont want to use seam; coz the stateless serrion bean/EJB is written by another developer and we cant updat eit now to use seam..
any tutorials? walk thrus or sample code?
thanks
illi

I used a different method...
I used servicegen with only a.jar to create the ear.
I touch-ed my own application.xml to make it newer than the one already in the
newly created ear.
I used the ant <ear> task to add b.jar, c.jar, and application.xml to the ear.
Worked like a charm.
Mike
Bruce Stephens <[email protected]> wrote:
Hello,
See if Neal's answer here helps solve your problem using servicegen's
service element "IncludeEJBs" attribute:
http://newsgroups.bea.com/cgi-bin/dnewsweb?cmd=article&group=weblogic.developer.interest.webservices&item=2932&utag=
HTHs,
Bruce
kk wrote:
This is my situation.
I have an .ear file and in that i have several other .jar files whichare
inter-dependant, lets say
A.jar
B.jar
C.jar files
and i want to expose only A.jar as
webservice, how can i do that ?
Does WLS8.1 provided any way how to do that?
I Appreciate any suggestions and advices.
Thanks
kk

Stateful vs. stateless session bean

Hi,
I am following the pattern of accessing entity beans with a session bean wrapper. I am just wondering if it's more efficient to make it a stateful session bean by keeping references to the home interfaces or make it stateless and do a lookup every time the session bean is created/activated?
I suppose the number of entity beans I want to access might make a difference. If so, is there a rough number when one way becomes better than the other?
Thanks for any help in advance.
Jeff

- It is far better to use a stateless session bean when implementing the session-facade pattern.
- Keeping a home interface on the object won't make him stateful.
- with the stateless beans, you do not decide when they're created. The container does.
- The number of entity beans is not so important. The only thing important is to have a remote methode in your stateless(es) for each atomic transaction ("atomic" meaning here "you cannot cut").
/Stephane

How to integrate hibernate with Stateless Session bean in weblogic10.0

Hi,
I need to invoke hibernate(3.x) DAO from EJB Stateless Session bean(EJB2.x). I am using mysql database. Can somebody please post the configuration.
Thanks in advance,
Rushi.

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.

How can i expose a stateless session bean with in .ear as web service?

This is my situation.
I have an .ear file and in that i have several other .jar files which are
inter-dependant, lets say
A.jar
B.jar
C.jar files
and i want to expose only A.jar as
webservice, how can i do that ?
Does WLS8.1 provided any way how to do that?
I Appreciate any suggestions and advices.
Thanks
kk

I used a different method...
I used servicegen with only a.jar to create the ear.
I touch-ed my own application.xml to make it newer than the one already in the
newly created ear.
I used the ant <ear> task to add b.jar, c.jar, and application.xml to the ear.
Worked like a charm.
Mike
Bruce Stephens <[email protected]> wrote:
Hello,
See if Neal's answer here helps solve your problem using servicegen's
service element "IncludeEJBs" attribute:
http://newsgroups.bea.com/cgi-bin/dnewsweb?cmd=article&group=weblogic.developer.interest.webservices&item=2932&utag=
HTHs,
Bruce
kk wrote:
This is my situation.
I have an .ear file and in that i have several other .jar files whichare
inter-dependant, lets say
A.jar
B.jar
C.jar files
and i want to expose only A.jar as
webservice, how can i do that ?
Does WLS8.1 provided any way how to do that?
I Appreciate any suggestions and advices.
Thanks
kk

Stateful/Stateless Session Bean combination

Hi.
Im in the process of designing a small card game(2-4 concurrent players), and I need to keep the state stored somewhere. I was thinking about putting most of the functionality together with state in a stateful session bean, but that doesnt scale very well.
Another option is to have the state stored on the client side and use stateless session beans, but then I have to pass state data on every method call.
I was thinking of another solution, using small light-weight stateful session beans to hold the state information, and link them to stateless session beans who do the hard work(with local interfaces).
Is this a good solution which will scale well?
How many bytes of memory do you think a SFSB with a couple of strings or integers + a reference to a SLSB will take? Thank you.

Hint:
To improve performance, you might choose a stateless session bean if it has any of these traits:
- The bean's state has no data for a specific client.
- In a single method invocation, the bean performs a generic task for all clients. For example, you might use a stateless session bean to send an email that confirms an online order.
- The bean fetches from a database a set of read-only data that is often used by clients. Such a bean, for example, could retrieve the table rows that represent the products that are on sale this month.
http://java.sun.com/j2ee/1.4/docs/tutorial-update2/doc/EJBConcepts3.html

Stateless session Bean - xml and ejb-jar.xml file ???

Dear Experts,
Stateless-session bean
For Creating an ear file
we need ejb-jar.xml and weblogic-ejb-jar.xml files
Is these files are already available
or we have to type these files ??
Advance Thanks
Rengaraj.R

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

How Stateless Session Bean instances in pool

Hi,
I am not clear about , stateless bean having "pool" of objects to be used by multiple clients.when those instances will be created or who will generate them.
Is this pool specific to ejb container or any vendor container.
thanks in advance,

Hi , my question is about Stateless Session Bean ,
how StatelessSession bean will behave when some 100
clients wil call homeObject simultaneously.The EJBs(including stateless) are single threaded so one client can access one Bean at a time. As per your question if some 100 clients are invoking home.create() method then it has to invoke on 100 EJBs. The instance pool size can be specified while deploying. In the descriptor (application server speific). So if the number of simultaneous clients is more than the pool size then some clients have to wait.
Now my second question is how and who will create
these instance .The container will create the pool as per the application server spcific deployment descriptor.

Stateless session beans and idle timeouts (weblogic 10.3.1)

Need clarification about stateless session beans and the idle-timeout-seconds setting.
Situation is this – we have a process that is timing out due to an API call to a very slow Authentication server.
I am trying to resolve this with a code change, but need to further other understand what the server is actually doing.
We have a session bean which calls another which is calling a util class that does all the work and returns the results back up to the initial session bean. I have left out the ejbName in these examples (it’s irrelevant here).
Example:
SessionBean1 // basically called just once a day
@Session(defaultTransaction = Constants.TransactionAttribute.SUPPORTS,
enableCallByReference = Constants.Bool.TRUE,
type = Session.SessionType.STATELESS,
transTimeoutSeconds = "0",
initialBeansInFreePool = "0",
maxBeansInFreePool = "20")
Methods
@RemoteMethod() public boolean getUserList(String adminGroup) {
Map usrList = getUserList(adminGroup);
Private Map getUserList(String adminGroup) {
     return SessionBean2.getUsers(adminGroup);
SessonBean2
@Session(defaultTransaction = Constants.TransactionAttribute.SUPPORTS,
enableCallByReference = Constants.Bool.TRUE,
type = Session.SessionType.STATELESS,
transTimeoutSeconds = "0",
initialBeansInFreePool = "3",
maxBeansInFreePool = "20")
Method
@RemoteMethod() public Map getUsers(String adminGroup) throws RemoteException {
return javaUtilClass.getUsers(adminGroup);
JavaUtilClass
Method
public Map getUsers(String adminGroup) throws RemoteException {
     // This is where the work happens, calling the Authentication server to get a complete
     // list of users for an admin group. When the user list is around 1500 entries, this can
     // take an hour. Did I mention this server is very slow? It’s about this threshold of 1500
     // that causes the timeout.
     return Map of users
First thought, just bump the idle-timeout-seconds setting for the session beans (from the default 600), but that would be a temporary solution until the user list grew larger.
Second thought, refactor the call to the Authentication Server API to get the user list in blocks of data (say 400 at a time) and decreasing the call/response time between the method getUsers and the API call. This would still occur in the JavaUtilClass, so I am unsure this would make a difference. The session beans would still be idle and subject to timeout, correct?
Would setting initialBeansInFreePool to 1 in SessionBean1 make any difference?
Or should I be looking at replicating the re-factored method from the JavaUtilClass in SessionBean1 where the user list is being used so that the API calls come back to it and keep it 'active'?
Thanks for any advice you could give me on this.

Hi
regarding timeouts, there are two ways:
1.- Changing the settings in the JTA WebLogic domain , called "Timeout Seconds". This will affect globally to all EJB deployed in the domain.
or
2.- Specified directly in the bean with a weblogic annotation, like this:
@TransactionTimeoutSeconds(value = 300)I hope this will help you.
Regards.
Felipe

It's a WebService and a Stateless Session bean

Ok,
I have a Stateless Session Bean that have annotated as a @WebService.
@Stateless
@WebService
public class TravelAgentWSBean {
I only call it as a WebService, never as a StatelessSessionBean. Do I get the exact same transactional behaviour as if it was a Stateless Session Bean?
Thanks.

You could try it like this
<c:catch var="formatError">
<fmt:formatNumber value="${row.payment}" type="currency" currencySymbol="" var="pay"/>
</c:catch>
<c:if test="${not empty formatError}">
Error formatting value <c:out value="${row.payment}"/>
</c:if>

How to get stateful and stateless session bean in second jsp

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