Need of session bean in ejb?

We can have the session beans business logic in Servlet using some support class(may be bean).I would like to know exact purpose & use of session bean in ejb specification.

We can have the session beans business logic in
Servlet using some support class(may be bean).I would
like to know exact purpose & use of session bean in
ejb specification.You can think of a SessionBean as a script. It handles certain business logic, for example, like book a flight. It might get the itinerary, charge the credit card, book a flight, etc. Usually, it is used as a facade, or front to one or more entity beans.
Now, you could do these exact same things with servlets, but the session bean allows you to have:
1. A single transaction scope. If one of your processes throws an exception and you've updated, for example 2 database tables, this transaction can be rolled back and everything will be consistant.
2. Servlets, by nature, are threaded and you have to take special care with synchronization issues of any member variables that you may use in the servlet. With EJBs there are no synchronization issues.
3. Security. You can specifically disallow/allow access to methods based on roles that you define.
These are the big reasons for using EJBs. Yes, you can do all of this with servlets, but you'd have to do it yourself ... but why do it, if it is already done for you.
I hope that that clears things up.
Regards,
Paul

Similar Messages

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???

EJB 2.1 session bean calling EJB 3 session bean?

I have a WL 10 (JDK 1.5/EE 5) server that has several EJB 3 stateless session beans deployed and working well. But now I need to allow a JBoss 3.2.3 (JDK 1.4) EJB 2.1 session bean make remote calls into these EJB 3 EJBs. Can this even work?
It seems to me that EJB 3 calling EJB 2 would be fine, but not in the reverse?

I have a WL 10 (JDK 1.5/EE 5) server that has several EJB 3 stateless session beans deployed and working well. But now I need to allow a JBoss 3.2.3 (JDK 1.4) EJB 2.1 session bean make remote calls into these EJB 3 EJBs. Can this even work?
It seems to me that EJB 3 calling EJB 2 would be fine, but not in the reverse?

Local Session Bean calling another local Session Bean in EJB 3.0

Hi,
In EJB 3.0, I am trying to do JNDI lookup of a local sesion bean from another session bean's helper class.
I am not using @EJB injection mechanism here, as call to the local session bean is made in a helper class. Helper classes do not support resource injection.
Following are the EJB class definitions used in my project. Call to "EJB3Local" made from "EJB1" fails as the "EJB2" helper class is calling "EJB1Local"
@Stateless
@EJBs({@EJB(name="EJB2Local", beanInterface=EJB2Local.class),
@EJB(name="EJB3Local", beanInterface=EJB3Local.class)})
public class EJB1 implements EJB1Remote, EJB1Local{
public void findEJB3Local(){
//1. JNDI lookup for EJB3Local ----
//2. EJB3Local.someFunction()
@Stateless
@EJB(name="EJB1Local", beanInterface=EJB1Local.class)
public class EJB2 implements EJB2Remote, EJB2Local{
public void findEJB1Local(){
//1. JNDI lookup EJB1Local
// 2. Call EJB1Local.findEJB1Local method
@Stateless
public class EJB3 implements EJB3Remote, EJB3Local{
public void someFunction(){}
A remote call to EJB2.findEJB1Local() will invoke EJb1Local.findEJB3Local method and the call fails with "java:comp/env/EJB3Local" not found in EJB1Local.
Has anybody encountered an issue like this issue with local interface calling another local interface?
Thanks,
Mohan

To refer a Ejb from another Ejb include <ejb-ref> element
in ejb-jar.xml
<session>
<ejb-name>SessionBeanA</ejb-name>
<ejb-ref>
<ejb-ref-name>SessionBeanB</ejb-ref-name>
<ejb-ref-type>Session</ejb-ref-type>
<home>com.ejb.SessionBeanBHome</home>
<remote>com.ejb.SessionBeanB</remote>
</ejb-ref>
</session>
Include a <reference-descriptor> in weblogic-ejb-jar.xml
<weblogic-enterprise-bean>
<ejb-name>SessionBeanA</ejb-name>
<reference-descriptor>
<ejb-reference-description>
<ejb-ref-name>SessionBeanB</ejb-ref-name>
<jndi-name>com.ejb.SessionBeanBHome</jndi-name>
</ejb-reference-description>
</reference-descriptor>
</weblogic-enterprise-bean>
In SessionBeanA Bean class refer to SessionBeanB with
a remote reference to SessionBeanB.
InitialContext initialContext=new InitialContext();
SessionBeanBHome sessionBeanBHome=(SessionBeanBHome)
initialContext.lookup("com.ejb.SessionBeanBHome");
SessionBeanB sessionBeanB=sessionBeanBHome.findByPrimaryKey(primarykey);
sessionBeanB.update();
sessionBeanB.getAll();
thanks,
Deepak

Stateful Session Bean Initialization (EJB 3.0)

Hi all!
In EJB 2.1 the initialization was with create (args) methods. NOw, how is it exploited? Create methods are no more there and there must be a way to send parameters to the stateful session bean when it is newly created...isn't it?
Thank you!

There is no pre-defined equivalent of a create method in EJB 3.0. If you want to initialize a
stateful session bean, just define a business method that the client should use as an initialization
method.

Local session bean lookup in another local session bean in EJB 3.0

Hi,
I am doing JNDI lookup of a local session bean in a session bean. ( I do not want to use EJB dependency injection).
Lookup of local interface from session bean is successful. But, when the calling session bean is a local session in another session bean, the lookup fails.
Here is an example:
@Stateless
@EJBs({@EJB(name="EJB2Local", beanInterface=EJB2Local.class),
@EJB(name="EJB3Local", beanInterface=EJB3Local.class)})
public class EJB1 implements EJB1Remote, EJB1Local{
public void findEJB3Local(){
//1. JNDI lookup for EJB3Local ----
//2. EJB3Local.someFunction()
@Stateless
@EJB(name="EJB1Local", beanInterface=EJB1Local.class)
public class EJB2 implements EJB2Remote, EJB2Local{
public void findEJB1Local(){
//1. JNDI lookup EJB1Local
// 2. Call EJB1Local.findEJB1Local method
//THIS METHOD CALL WILL FAIL.
public void findEJB1Remote(){
//1. JNDI lookup EJB1
/ 2. Call EJB1Local.findEJB1 method
@Stateless
public class EJB3 implements EJB3Remote, EJB3Local{
public void someFunction(){}
This setup was working in EJB 2.1, as we had clear ejb-local-ref definitions in our ejb-jar.xml file.
I am suspecting that EJB 3.0 has special annotation to use when lookup is made from another local session bean.
Any comments will be appreciated.
Thanks,
Mohan

From a private component environment perspective, declaring @EJB in a bean class is equivalent
to using ejb-ref or ejb-local-ref for that same bean in ejb-jar.xml. In each case, the EJB dependency
is declared for that bean. Each EJB component has its own private component environment, so
code running within invocations on different EJBs can not see the component environment of the
components that made the invocations.
What exact error are you getting? Please post the stack trace if possible.
--ken

How to intantiate Stateful session bean in EJB 3 ?

In EJB 2.x, to instantiate a Stateful Session bean the process was:
1. Lookup Home object
2. call create(args) method on Home, that in turn would call corresponding ejbCreate(args) on the bean implementation.
Now, in EJB 3, there is no concept of Home interaface, How can I instantiate a stateful session bean with some initialization parameters.
Thanks

Just the spec. NetBeans should only be providing the ability to add an ejbCreate method if the bean exposes a Local or Remote 2.x view.
Each lookup or injection of a stateful session bean results in a new bean instance. As long as you call your methods to populate the additional
state right after first acquiring the stateful session bean reference it will work.
--ken

EJB 3.0 Session Bean question

Hi there,
How'd I expose a method of Stateless Session Bean in EJB 3.0? I don't seem to find any annotation for that.
Thanks in advance.
Saeed

If you need to expose method implemented in Session bean, you can invoke the method call from within another method called in Client.
This method has to be defined in the remote interface . The method you are trying to invoke can be defined somewhere else but called in your bean class from within the method definedin the remote interface.

Deploying EJB 3 session beans on OC4J 10.1.3.0.0 Standalone

Guys,
I am unable to deploy any EJB 3.0 session beans on my freshly installed OC4J 10.1.3.0.0 instance. I also have tried to deploy the EAR created by the "Develop a Stateless Session Bean using EJB 3.0" to eliminate problems in the deployed archive, but itfails with the exact same stacktrace:
06/06/05 14:38:52 SEVERE: ProgressObjectImpl.reportError java.lang.InstantiationException: Error initializing ejb-module
s: nested exception is: java.lang.reflect.InvocationTargetExceptionoracle.oc4j.admin.jmx.shared.exceptions.InternalExcep
tion: java.lang.InstantiationException: Error initializing ejb-modules: nested exception is: java.lang.reflect.Invocatio
nTargetException
at oracle.oc4j.admin.jmx.shared.deploy.NotificationUserData.<init>(NotificationUserData.java:107)
at oracle.oc4j.admin.internal.Notifier.reportError(Notifier.java:429)
at oracle.oc4j.admin.internal.DeployerBase.execute(DeployerBase.java:123)
at oracle.oc4j.admin.jmx.server.mbeans.deploy.OC4JDeployerRunnable.doRun(OC4JDeployerRunnable.java:52)
at oracle.oc4j.admin.jmx.server.mbeans.deploy.DeployerRunnable.run(DeployerRunnable.java:81)
at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Worker.run(PooledExecutor.java:819)
at java.lang.Thread.run(Thread.java:595)
Caused by: oracle.oc4j.admin.internal.DeployerException: java.lang.InstantiationException: Error initializing ejb-module
s: nested exception is: java.lang.reflect.InvocationTargetException
at oracle.oc4j.admin.internal.DeployerBase.execute(DeployerBase.java:126)
... 4 more
Caused by: java.lang.InstantiationException: Error initializing ejb-modules: nested exception is: java.lang.reflect.Invo
cationTargetException
at com.evermind.server.ejb.EJBContainer.postInit(EJBContainer.java:1056)
at com.evermind.server.ApplicationStateRunning.initializeApplication(ApplicationStateRunning.java:210)
at com.evermind.server.Application.setConfig(Application.java:391)
at com.evermind.server.Application.setConfig(Application.java:308)
at com.evermind.server.ApplicationServer.addApplication(ApplicationServer.java:1771)
at oracle.oc4j.admin.internal.ApplicationDeployer.addApplication(ApplicationDeployer.java:507)
at oracle.oc4j.admin.internal.ApplicationDeployer.doDeploy(ApplicationDeployer.java:191)
at oracle.oc4j.admin.internal.DeployerBase.execute(DeployerBase.java:93)
... 4 more
Caused by: javax.ejb.EJBException: nested exception is: java.lang.reflect.InvocationTargetException
at com.evermind.server.ejb.EJBUtils.createEJBException(EJBUtils.java:352)
at com.evermind.server.ejb.EJBUtils.createEJBException(EJBUtils.java:343)
at com.evermind.server.ejb.POJOEntityAnnotationListener.parseAnnotatedClass(POJOEntityAnnotationListener.java:56
at com.evermind.server.ejb.AnnotationParser.notifyAnnotationListeners(AnnotationParser.java:197)
at com.evermind.server.ejb.AnnotationParser.parseAnnotations(AnnotationParser.java:69)
at com.evermind.server.ejb.EJBPackageDeployment.parseMetaData(EJBPackageDeployment.java:964)
at com.evermind.server.ejb.EJBContainer.postInit(EJBContainer.java:831)
... 11 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at com.evermind.server.ejb.POJOEntityAnnotationListener.parseAnnotatedClass(POJOEntityAnnotationListener.java:48
... 15 more
Caused by: java.lang.NullPointerException
at java.lang.Class.getAnnotation(Class.java:2956)
... 20 more
Also, and this is probably related, when starting up it the app server prints:
6-06-05 14:38:51.777 WARNING J2EE EJB5003 EJB 3.0 enabled but JDK 1.5 is not in use. No annotations will be parsed.
Which is not true as I am running JDK 5.0_6 and I have tested/validated this by deploying a working (working as in putting stuff in and pulling stuff out of a db) EJB 3.0 Persistence project in there, which uses annotations.
I really hope somebody on the OC4J team can help me out on this, as I am guessing a lot of people will run into this.
Kind regards,
Mik

Well, I think I at least isolated the problem:
My installation was not as fresh as I thought. It had to do with my trying to get the latest version of TopLink (the final EJB 3.0 RI one) running on the latest OC4J standalone. For this I deleted the j2ee/home/persistence.jar and replaced it by toplink-essentials.jar. I apparently misjudged the differences that occured in the last steps of the EJB 3 specs.
So let me rephrase my question: is there a way to get the latest version of TopLink (the one packaged as the EJB3 Persistence RI) in the OC4J 10.1.3.0 Standalone container? And if not, when will there be one?
Mik

Injecting session bean from different EAR

Dear all,
I am using ejb3. i have ejb.ear and web.ear. both deploy in same weblogic server.
i want to inject session bean from ejb.ear inside web.ear.
With Regards,
WP

hi,
Currently, we want to separate it. Because may be we will deploy in different server in the future.
So far, i can inject it using remote interface.
How about local interface? is it possible to use local interface? because so far both deploy on same server.
As far as i know, glassfish can't. isn't it?
it is j2ee standard or server specific?
With Regards,
WP

Could not access Local Session Bean using JNDI lookup

Hi EJB Guru,
I am quite new to EJB 3.0 but have had a good deal of success including using JNDI to lookup Remote Stateless Session Bean in EJB 3.0. However, looking up local Stateless Session Bean prove more challenging with I had anticipated.
Here is my code
as follows:
public interface Calculator {
    public int add(int x, int y);
    public int subtract(int x, int y);
import javax.ejb.Remote;
@Remote
public interface CalculatorRemote extends Calculator {
import javax.ejb.Local;
@Local
public interface CalculatorLocal extends Calculator {
import javax.ejb.Local;
import javax.ejb.Remote;
import javax.ejb.Stateless;
import bean.CalculatorLocal;
import bean.CalculatorRemote;
@Stateless
public class CalculatorBean implements CalculatorRemote, CalculatorLocal {
    public int add(int x, int y) {
        return x + y;
    public int subtract(int x, int y) {
        return x - y;
import bean.*;
import bean.Calculator;
import bean.CalculatorLocal;
import javax.naming.InitialContext;
import javax.naming.NamingException;
public class ClientAccessLocalCalculator {
    public static void main(String[] args) throws NamingException {
        InitialContext ctx = new InitialContext();
        CalculatorLocal calculator = (CalculatorLocal) ctx.lookup("CalculatorBean/local");
        System.out.println("1 + 1 = " + calculator.add(1, 1));
        System.out.println("1 - 1 = " + calculator.subtract(1, 1));    }
import bean.Calculator;
import bean.CalculatorRemote;
import javax.naming.InitialContext;
import javax.naming.NamingException;
public class ClientAccessRemoteCalculator {
    public static void main(String[] args) throws NamingException {
        InitialContext ctx = new InitialContext();
        CalculatorRemote calculator = (CalculatorRemote) ctx.lookup("CalculatorBean/remote");
        System.out.println("1 + 1 = " + calculator.add(1, 1));
        System.out.println("1 - 1 = " + calculator.subtract(1, 1));    }
}Output when running ClientAccessRemoteCalculator gives
1 + 1 = 2
1 - 1 = 0
Output when running ClientAccessLocalCalculator on JBoss AS 4.0.5 gives:
Exception in thread "main" javax.ejb.EJBException: Invalid invocation of local interface (null container)
at org.jboss.ejb3.stateless.StatelessLocalProxy.invoke(StatelessLocalProxy.java:75)
at $Proxy0.add(Unknown Source) at ClientAccessLocalCalculator.main(ClientAccessLocalCalculator.java:14)
JNDIView in JMX-Console in JBoss:
+- CalculatorBean (class: org.jnp.interfaces.NamingContext)
| +- local (proxy: $Proxy84 implements interface bean.CalculatorLocal,interface org.jboss.ejb3.JBossProxy,interface javax.ejb.EJBLocalObject)
| +- remote (proxy: $Proxy83 implements interface bean.CalculatorRemote,interface org.jboss.ejb3.JBossProxy,interface javax.ejb.EJBObject)
Output when running ClientAccessLocalCalculator on SJSAS 9.0 gives:
Exception in thread "main" javax.naming.NameNotFoundException: bean.CalculatorLocal not found
C:\>asadmin
Use "exit" to exit and "help" for online help.
asadmin> list-jndi-entries
Jndi Entries for server within root context:
bean.CalculatorRemote: javax.naming.Reference
jbi: com.sun.enterprise.naming.TransientContext
jdbc: com.sun.enterprise.naming.TransientContext
UserTransaction: com.sun.enterprise.distributedtx.UserTransactionImpl
bean.CalculatorRemote__3_x_Internal_RemoteBusinessHome__: javax.naming.Reference
bean.CalculatorRemote#bean.CalculatorRemote: javax.naming.Reference
ejb: com.sun.enterprise.naming.TransientContext
Command list-jndi-entries executed successfully.
asadmin>I am using Application Client to lookup these Session Beans on Netbeans 5.5, JBoss AS 4.0.5 (EJB3 installer)/SJSAS
9.0, SDK 1.5.0_11 on Windows XP platform.
Any assistance would be much appreciated.
Many thanks,
Henry

Hi Henry,
Any direct global JNDI lookup is not portable. It works in some cases but not in others, which
is why we recommend using the portable Java EE approach of declaring an ejb dependency
and looking up that dependency via the bean's component environment (java:comp/env).
This is true whether you're dealing with Remote or Local ejb dependencies.
Local ejbs are not supported in the Application Client tier at all. In the server tier, there is no
guarantee that a Local EJB even is assigned a global JNDI name since there's no requirement
that it be available outside of the application in which the ejb is defined.
You can find more information on these ejb access topics in our EJB FAQ :
https://glassfish.dev.java.net/javaee5/ejb/EJB_FAQ.html

Help needed in EJB - to call AS from EJB a Session Bean

Hi All ,
I have been strictly told not to use Web Services as all the applications are on the same server
actually I have to make an EJB invocation to an Application Service from the CAF layer from a Session Bean of another EJB Project(Not a CAF Service).
the CAF layer has 5 parts metadata , permissions , dictionary , ear and ejbmodule.
I added the ejbModule to the Build Path of the calling EJB Session Bean. And so I was able to access the operations of the Application Service which in turn accesses a BAPI(The Appl Service operation returns a String).
But while executing I got the exception java.lang.RuntimeException: java.lang.NoClassDefFoundError
My method :
Normally from a Dynamic Web Project acting as a client to an EJB Session bean, I was able to get access to EJB Local Interface by using
private ConverterLocal converterBean = null;
public void jspInit() {
    try {
     InitialContext ic = new InitialContext();
     converterBean = (ConverterLocal)
     ic.lookup("java:comp/env/Converter");
    } catch (Exception ex) {
         System.out.println("Couldn't create converter bean."+
       ex.getMessage());
BigDecimal dollarAmount = converterBean.euroToDollar(value);
So I created a JNDI field in ejb-j2ee-engine.xml
enterprise-beans>
        <enterprise-bean>
     <ejb-name>com.sap*******.bapi_company_getlist.BAPI_COMPANY_GETLIST</ejb-name>
               <jndi-name>COMPANY</jndi-name>
            </enterprise-bean>
</enterprise-beans>
And from my Session Bean , I tried to access it using the code in already existing Bean which was working fine
BAPI_COMPANY_GETLISTBeanImpl bean = new BAPI_COMPANY_GETLISTBeanImpl();
          try {
               InitialContext ctx = new InitialContext();
               bean = (BAPI_COMPANY_GETLISTBeanImpl)ctx.lookup("COMPANY");
          } catch (NamingException e) {
               System.out.println("Converter Bean can't be created");
               String send = bean.returnDetails();
And I tried to print the String , but I got the above error
I have a doubt :
1) How do I specify the JNDI name ie in the ejb-j2ee-engine.xml file , what should I add as the name of the ejb
is this sufficient , or are there more steps ??

Hi Ekaterina,
I have the document to access my Bean from another Bean.
I could access my Bean from a standalone Java class with this code
Properties props = new Properties();
          props.put(Context.INITIAL_CONTEXT_FACTORY,"com.sap.engine.services.jndi.InitialContextFactoryImpl");
          props.put(Context.PROVIDER_URL,"hostname:port");
          try{
               Context ctx = new InitialContext(props);
               Object o = ctx.lookup("sap.com/TestEAR/REMOTE/TestBean/com.@#$.TestRemote");
               TestRemote testRem = (TestRemote)javax.rmi.PortableRemoteObject.narrow(o, TestRemote.class);
               String msg = testRem.getMessage();
               System.out.println(msg);
And in this document there is a way shown to access a bean from another Bean.
   http://help.sap.com/saphelp_nw04/helpdata/en/13/c8633e0084e946e10000000a114084/frameset.htm
If your client is another enterprise bean, declare the EJB reference in the ejb-jar.xml.
-For more information, see Declaring EJB References.
But the problem is that in EJB 3.0 , I can't see the ejb-jar.xml file .
So how should I have a Bean as a client to another Bean, I am not that familiar with Annotations.

How can i design a EJB application using session Beans?

Hello,
I am designing a Find application using EJB. Here a user is prompted a search page, where he can enter the search criteria's. Then on click of submit, the query is formed at the server side depending on what criteria's were selected. Then a jdbc query is performed and the results are returned back to the user. Here no session is maintained for the users. Can anyone suggest me how to design this application using EJB. Should i use entity beans for this or session beans will suffice? Should the jdbc query be performed in the bean itself or should it be outside in a helper class? Please kindlu suggest me the design for this application...
Regards,
Subbu

Hi,
First of all, I'm unable to figure out why you need to use EJB for this scenario. You can write a helper class to frame and execute the query.
If you really want to use EJB, then I suggest you use a stateless Session Bean with transaction attribute as TX_NOT_SUPPORTED. From the session bean, you can call the helper class. But, by avoiding the session bean, you can eliminate remote calls, thus improving your performance. Also, check if the database & the db driver you are using supports sql caching.
Regards,
Raj.

EJB 3.0 - Communicate an Applet with a Session Bean

Hello
I'm developing an EJB 3.0 app (eclipse and glassfish tools bundle), and I have an applet that has to use remote session beans.
QUESTION: Is it possible for the applet to connect to EJB?
QUESTION: By creating a J2EE application client project, can I use @EJB annotations to inject the session bean directly to the applet, avoiding the JNDI lookup?
(since I imagine that the anwser to the second one is NO, I do the following consideration)
Given an application client project, I imagine that this application can run remotely on a client machine/JRE. Then this application can use Annotations/injection facilities whenever it runs on a J2EE client container (which I assume consists of a set of libraries provided by the application server vendor, Glassfish in that case). Could this application be deployed using Java Web Start? If so, why can't it be deployed as an applet? (both options run in a client JRE, don't they?).
QUESTION: In either case (applet or JWS), how do I have to package the JAR file (using Eclipse) so that it contains the needed libraries for accessing the EJB? Which are those libraries?
At the time being, I'm trying to implement a sample application that follows the "Applet doing JNDI lookup" approach. I have:
- an EAR project
- an EJB project (containing an Entity Bean and a Stateless Session Bean with a @Remote interface)
@Remote
public interface HelloRemote {
     public String hello(String name);
@Stateless
public class Hello implements HelloRemote {
     @Override
     public String hello(String name) {
          return "Hello "+name+"!!";
}- an Application Client project (containing the applet code):
public class ClientApplet extends JApplet {
     public void init(){
          try {
               Context jndiContext = getInitialContext( );
               HelloRemote server = (HelloRemote) jndiContext.lookup(HelloRemote.class.getName());
               setContentPane(new JLabel(server.hello("Gerard")));
          } catch (NamingException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
     private Context getInitialContext() throws NamingException{
          Properties props = new Properties();
          props.setProperty("java.naming.factory.initial", "com.sun.enterprise.naming.SerialInitContextFactory");
          props.setProperty("org.omg.CORBA.ORBInitialHost", "myhost");
          props.setProperty("org.omg.CORBA.ORBInitialPort", "3700");
          return new InitialContext(props);
}- a static web project (with a sample web page that contains the applet object the corresponding applet JAR file)
I tried to export the Application Client project as an "application client JAR", in the hope that the java EE libraries bundled with glassfish (listed as libraries of this project) would be packaged too.
No success, so now I'll try to copy all the JAR files (one by one) into the +\WebContent\+ folder of the Web Project, and add references to each of them in the archive="" attribute of the +<applet>+ HTML tag. Although this might work, I suspect that I am missing the good/easy way of doing it. Any suggestions?
Thanks in advance,
Gerard
Edited by: gsoldevila on May 6, 2009 7:09 AM

An Applet can communicate with an EJB via JNDI lookup but I would (personally) use an intermediate Servlet to handle this. Client to Servlet communication is http whereas to ejb is iiop - which might be blocked.
Injection only works in managed classes (EJB, Servlet, Listeners..) and an Application Client main class. So yes you could use an app client for handling resource injection.
m

Problem calling a session bean (EJB 3.0)

Hello,
I'm new to netbeans and J2EE. I'm using NetBeans 5.5 Beta 2 and sun application server 9 pe.
I created a new enterprise application and i'm trying to access a Session Bean (Remote and Stateless)
from the app-client (outside the main class).
This is the loockup method that was generated by the IDE (Enterprise Resources > Call enterprise bean):
private ejb.SessionBeanDoenteRemote lookupSessionBeanDoenteBean() {
try {
javax.naming.Context c = new javax.naming.InitialContext();
return (ejb.SessionBeanDoenteRemote) c.lookup("java:comp/env/ejb/SessionBeanDoenteBean");
catch(javax.naming.NamingException ne) {
java.util.logging.Logger.getLogger(getClass().getName()).log(java.util.logging.Level.SEVERE,"exception caught" ,ne);
throw new RuntimeException(ne);
When I run the application and try to invoke the lookup method my application gets the following exception:
SEVERE: exception caught
javax.naming.NameNotFoundException: No object bound to name java:comp/env/ejb/Se
ssionBeanDoenteBean
at com.sun.enterprise.naming.NamingManagerImpl.lookup(NamingManagerImpl.
java:751)
at com.sun.enterprise.naming.java.javaURLContext.lookup(javaURLContext.j
ava:156)
at com.sun.enterprise.naming.SerialContext.lookup(SerialContext.java:307
at javax.naming.InitialContext.lookup(InitialContext.java:351)
at intensivecare.entrada.JDialogEntrada.lookupSessionBeanDoenteBean(JDia
logEntrada.java:219)
at intensivecare.entrada.JDialogEntrada.buttonMenuGravarActionPerformed(
JDialogEntrada.java:79)
at intensivecare.JDialogWizzard$2.jButtonGravarActionPerformed(JDialogWi
zzard.java:178)
at componentes.JTaskPanelMenu$3.actionPerformed(JTaskPanelMenu.java:54)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:18
49)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.jav
a:2169)
Please... can someone help me?

The portable way to acquire the dependency is through java:comp/env or @EJB. Accessing the
global namespace directly is not recommended. If you use an ejb-ref, you need to define it
in the component environment within which you'll be looking up the dependency. So if you're
looking it up from an Application Client, you'll need to define the ejb-ref in application-client.xml.
Also, the ejb-ref-name is the portion of the string after java:comp/env. There is no automatic
"ejb" appended to it. If you do ic.lookup("java:comp/env/foo"), your ejb-ref-name would be "foo".
You can use @EJB but it can only be defined in certain managed classes such as the
Application Client main class.
You can find additional info in our EJB FAQ :
https://glassfish.dev.java.net/javaee5/ejb/EJB_FAQ.html
--ken

Need of session bean in ejb?

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