Session bean versus normal bean

Hi,
I am at design decision whether to uses a normal Java class or a stateless session bean. I basically need to get data in a list format (read only). I don?t have many users in the system. May be max 60 users online.
I am thinking of using a fast lane reader. For this I will use a helper class in my web layer maybe doing data access through a DAO. My friends say to use a session bean because of object pooling, clustering etc. I am still convinced a normal class will do. Please help me out with any advice.
Thanks,
Gavin

A Session Bean can be a fast lane reader if you want. The data-reading aspect relates more to Entity Beans than to Session Beans.
If you're simply after a snapshot of the data then I'd opt for a Session Bean that hits the database directly through a utility class (your fast lane reader).
EJBs are useful for providing configurable access to resources and get you security, transactional isolation, pooling etc.. These advantages carry an overhead - the EJB life-cycle - which can become prohibitive in some circumstances. However, you'd be unwise to throw away the benefits without first gauging the impact of this overhead.
It must be noted here that most of the benefits (except security) are probably of little interest to your situation; you don't really need much in the way of clustering or pooling as there's no state being maintained, transactional isolation isn't really relevant either. But then again, how else will you write a server-side component that accesses the database? Or are you going to access the database directly from the client (your web server)? Is the latter a good idea with your dataset? What does this do to your application's configuration? What are the security considerations? Is the number of users likely to increase in future?
There's no single answer to your problem as it will depend on many factors. I tend to opt for the simplest solution (Entity Beans for a small dataset or a Session Bean accessing the database for a large one) and defer optimisation until bottlenecks can successfully be measured.
Hope this helps.

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Call Bean from normal java class

Dear Friends,
Is it ok to call an entity bean or session bean frm normal Java class.
(Java class is in the same application as the beans).
Is there a special way to lookup the beans from normal java classes.
Thanking You,
Chamal.

it is ok and very commonly done.
Note that the simple java program must be running in the same local network. You cannot have the java program and EJBs distributed over internet. (I m not certain of it, but mostly I shoudl be correct. If you have the resources, try it out and let me know)
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1. A servlet
2. Another EJB
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However, in the third case, it is unlikey that you will have the client runnng and the same jvm as the server, because the app server has its own jvm.
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               nameHashtable.put( Context.INITIAL_CONTEXT_FACTORY, "weblogic.jndi.WLInitialContextFactory" );
               nameHashtable.put( Context.PROVIDER_URL, "t3://localhost:7001" );
               InitialContext context = new InitialContext(nameHashtable);
               System.out.println("created initial context");
               Object lookupObject = context.lookup("CustomerBean");
               System.out.println("Got the lookup object");
               CustomerDataHome home = (CustomerDataHome) PortableRemoteObject.narrow(lookupObject,
                         Class.forName("com.shiv.business.CustomerDataHome"));
               System.out.println("Home interface");
               customerData = home.create();
               System.out.println("Remote Interface");
               addDataToSB(customerData);
               ArrayList namesList = customerData.getNames();
               System.out.println(namesList.toString());
               //customerData.remove();
          catch (Exception exception)
               System.out.println("FATAL ERRORS");
               exception.printStackTrace();
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How to set session attributes in a bean?

How do I set a session attribute in a server-side bean?
I'm not sure if I asked the question the right way. What I meant is, while it's easy to set session attributes in a JSP page (session.setAttribute("sessionname", "sessionvalue")), I'd want to set such an attribute within a server-side bean defined in this web application. But what is the syntax for doing it?

Here a simple bean that stores something in the session and retrieves something from it.
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private String value;
public void doSomething(HttpSession session, int a, int b) {
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public void init(HttpSession session) {
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<%
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%>If your bean only lives during one request, you can pass the session to the constructor, which stores it in a private variable. This saves passing the session each time.
Hope this helps,
--Arnout

How can I set the value to a session bean from backing bean

Hi Experts,
How can I set the value to a session bean from backing bean where I have created getter and setter
methods for that variable.
Basically I am using ADFUtils class where I am able to get the value from session bean
using following expression
String claimType =
(String)ADFUtil.invokeEL("#{ClaimValueObj.getClaimType}");
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Gayaz

Gayaz,
Wrong Post !!
Post in JDeveloper and ADF
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--Anil

Hi, I have quick question about use of USEBEAN tag in SP2. When I specify a scope of SESSION for the java bean, it does not keep the values that I set for variable in the bean persistent.Thanks,Sonny

Make sure that your bean is implementing the serializable interface and that
you are accessing the bean from the session with the same name.
Bryan
"Sandeep Suri" <[email protected]> wrote in message
news:[email protected]..
Hi, I have quick question about use of USEBEAN tag in SP2. When I
specify a scope of SESSION for the java bean, it does not keep the
values that I set for variable in the bean persistent.Thanks,Sonny
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Access session values in Managed Bean

I want to acces session attribute values in my Managed Bean class.
This is my code in SecurityPhaseListener.java class,
HttpSession session = (HttpSession)facesContext.getCurrentInstance().getExternalContext().getSession(true);
String isAuthorized = "false";
session.setAttribute(isAuthorized, isAuthorized);
This is my configuration for My managed bean in faces-config.xml class
<managed-bean>
<managed-bean-name>setNewDayBean</managed-bean-name>
<managed-bean-class>com.hli.vipstar.uswm.setnewday.managedbean.SetNewDayBean</managed-bean-class>
<managed-bean-scope>request</managed-bean-scope>
</managed-bean>
Now i want to access the attribute "isAuthorized" in my managed bean SetNewDayBean.java.
How to do this?
Any one help me...........

The same way, but then using getAttribute() instead of setAttribute().
Another -more clean- way is to use the ExternalContext#getSessionMap(). It will make your code independent from the session implementation used. You may find this article useful as well: http://balusc.blogspot.com/2006/06/communication-in-jsf.html

Session Bean calling entity bean

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How does session bean calls entity bean in weblogic6.1
Thanks

have a look in the examples that come with weblogic
"Anand" <[email protected]> wrote in message
news:[email protected]..
>
>
Hi
How does session bean calls entity bean in weblogic6.1
Thanks

How to get and set a session variable from backing bean?

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Any idea?

the class :
package arq.resources;
import javax.faces.context.FacesContext;
import javax.servlet.http.HttpSession;
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public FacesContext context;
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super();
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I am building application in which I query 4 to 5 tables and display the reports
. Presently I am using JSP and Servlets but would like to move to EJBs.
What would be my best bet between Entity and Session beans ?
Thanks in advance ..Frank

Frank,
You may want to peruse the following snippet from Sun's Java site on when to use
session beans vs. entity beans
http://java.sun.com/j2ee/j2sdkee/techdocs/guides/ejb/html/Overview4.html#9377
Chuck Nelson
Developer Relations Engineer
BEA Technical Support

Weblogic 10.3.0 : Loosing a stateless session bean in the bean pool

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We have a strange situation where we loose a Stateless SessionBean in a Bean Pool in Weblogic 10.3.0 Since we only have one bean in the pool, this effectively hangs all incoming calls. We do not want more than one instance in the pool because of application restrictions.
In the Weblogic admin console, we can see that there are 1 instance in the bean pool, 0 beans in use and 1 waiting incoming request.
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This happens after several hours and over 100000 incoming requests, and the same scenario worked fine in the old weblogic 8 environment.
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<code>
"[ACTIVE] ExecuteThread: '5' for queue: 'weblogic.kernel.Default (self-tuning)'" waiting for lock java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@b0d484 TIMED_WAITING
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weblogic.ejb.container.manager.StatelessManager.preInvoke(StatelessManager.java:148)
weblogic.ejb.container.internal.BaseRemoteObject.preInvoke(BaseRemoteObject.java:227)
weblogic.ejb.container.internal.StatelessRemoteObject.preInvoke(StatelessRemoteObject.java:52)
com.mycompany.beans.MessageLogFacace_n73y0z_EOImpl.isMyStuffValid(MessageLogFacace_n73y0z_EOImpl.java:261)
com.mycompany.beans.MessageLogFacace_n73y0z_EOImpl_WLSkel.invoke(Unknown Source)
weblogic.rmi.internal.BasicServerRef.invoke(BasicServerRef.java:589)
weblogic.rmi.cluster.ClusterableServerRef.invoke(ClusterableServerRef.java:230)
weblogic.rmi.internal.BasicServerRef$1.run(BasicServerRef.java:477)
weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:363)
weblogic.security.service.SecurityManager.runAs(Unknown Source)
weblogic.rmi.internal.BasicServerRef.handleRequest(BasicServerRef.java:473)
weblogic.rmi.internal.wls.WLSExecuteRequest.run(WLSExecuteRequest.java:118)
weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
</code>
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Regards
Christer

This is fixed now. Someone had defined a Servlet for the web service in web.xml that was preventing the EJB container to kick in.
Edited by: user572625 on Aug 25, 2011 11:54 PM

Problem in calling single entity bean from other beans

Hi,
I am implementing session facade with SUN's J2EE 1.3 deploy tool for JBoss server.
I have a entity bean UserBean which creates users in database ( create() )and tells if user exists or not ( findByPrimaryKey() ).
Initially, I had implemented UserBean with remote interfaces. So, any servlet ( my client ) which needed to use UserBean would make a remote call to it. It was used by 5 different servlets.
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Suraj

I suggest you post to one of the forums on jboss.org. There should not be a problem AFAIK having remote and local interfaces to the same EJB. I assume that you gave these unique names (FooHome/FooLocalHome..etc...) for the home and remote interfaces and declared both in the ejb DD.

Creating a bean within another bean and JNDI

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Mike

thanks, but look at the new code i modified still given error on not resolving the class LoginBean in the class LoginDataBean. here is the new code.
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import java.sql.*;
import java.util.*;
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Injecting a bean in another bean in EJB3?

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I found why this happen but i can't fix it :
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Session bean versus normal bean

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