Servlet + Local EJBS

Hi,
I'm about to deploy the Servlet using the Local EJB interfaces. The problem
I've encountered is that when I try access the local home interface I get
the ClassCastException. But object returned does indeed implement the local
home interface. I suppose, there are some repeated classes both in ejb and
web deployments. Can someone tell me how to make my servlet access the same
classes as deployed local ejbs?
Thanks in advance,
Andrzej

Ok, that's the reason.
Thanks.
You can only access local EJBs within the application. Are you deployingthe
servlet and ejb together in an ear file?
-- Rob
Andrzej Dmoch wrote:
Hi,
I'm about to deploy the Servlet using the Local EJB interfaces. The
problem
I've encountered is that when I try access the local home interface Iget
the ClassCastException. But object returned does indeed implement thelocal
home interface. I suppose, there are some repeated classes both in ejband
web deployments. Can someone tell me how to make my servlet access thesame
classes as deployed local ejbs?
Thanks in advance,
Andrzej

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Hi,
I have a servlet and a local EJB. The servlet and EJB are deployed on same application server but in different J2EE applications i.e. different EAR files.
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Exception Stack: -
========================================================
avax.naming.NameNotFoundException: Context: localhost/nodes/localhost/servers/server1, name: TestLocalHome: First component in name TestLocalHome not found. Root exception is org.omg.CosNaming.NamingContextPackage.NotFound: IDL:omg.org/CosNaming/NamingContext/NotFound:1.0
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========================================================
Please help asap.
Regds
VJ.

The ejb spec only defines local ejb access within the same application. It's possible some app servers support access from a different application but it wouldn't be portable, nor would it work within the J2EE SDK or Sun Java System App Servers. To access a local ejb from a web component or ejb , define an ejb-local-ref in the client component's standard .xml file (web.xml or ejb-jar.xml) and use the ejb-link element to specify the ejb-name of the target ejb.
--ken

Unable to lookup local EJB reference (ejb 2.1)

Hi All,
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<?xml version="1.0" encoding="UTF-8"?>
<ejb-jar version="3.0" 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/ejb-jar_3_0.xsd">
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</ejb-jar>
and here is my weblogic-ejb-jar.xml
<?xml version="1.0" encoding="UTF-8"?>

<weblogic-ejb-jar
xmlns="http://www.bea.com/ns/weblogic/90" xmlns:j2ee="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.bea.com/ns/weblogic/90 http://www.bea.com/ns/weblogic/90/weblogic-ejb-jar.xsd">
<weblogic-enterprise-bean>
<ejb-name>XDCGIVTBatchController</ejb-name>
<stateless-session-descriptor>
</stateless-session-descriptor>
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</weblogic-enterprise-bean>
<weblogic-enterprise-bean>
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</weblogic-enterprise-bean>
</weblogic-ejb-jar>
I am using the following code to do the lookup
Object hm = new InitialContext().lookup("java:comp/env/ejb/local/XDCGIVTCursorHoldableJDBCReader);
I have also tried looking up with
java:comp/env/ejb/XDCGIVTCursorHoldableJDBCReader with no success.
Any ideas? suggestions? what am I doing wrong?
Thanks in advance!!
Neeraj

Hey Matt,
So the flow is as follows
1. Servlet looks up EJB1
2. EJB1 starts a commonj.work using the commonj.WorkManager
3. The worker tries to lookup EJB2 using java:comp/env (and thats the same place I tried to dump the namespace)
Could it be that I am getting a new namespace in the commonj worker ? This doesn't seem to be the case in IBM WebSphere.
Thanks for your help!
Neeraj

Servlets and EJBs

Hi,
My question, is possible to access from servlet some EJB through EJB's local interface, even these participate two different containers?
Regards
Krzysztof

I am not that good with EJB , but I donot think so
EJB Local interfaces only work from othe EJB's AFAIK,

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Hi ALL,
How do I call to local ejb from remote ejb object. The jar file is deployed on weblogic server 9.2, if you want get it http://geocities.yahoo.com.br/lindembe/BEAProject.jar and the source code are http://geocities.yahoo.com.br/lindembe/BEAProject.zip. It is a sample app with two ejb that works so good on JBOSS, JOnAS, but BEA Weblogic.....
The complete problem you watch http://forum.java.sun.com/thread.jspa?threadID=768718&messageID=4387570#4387570
or
http://forums.bea.com/bea/message.jspa?messageID=600043148&tstart=0

Your code in SigemFacadeBean should just do:
InitialContext ctx = new InitialContext();
when you lookup the local EJB. (This will work on all app servers. There's no need to put an app-server specific intial context factory in your code.)
Also, you can remove the jndi-name setting for the local ejb from your weblogic-ejb-jar.xml. jndi-name is only applied to remote ejbs.
-- Rob
WLS Blog http://dev2dev.bea.com/blog/rwoollen/

How to create a local EJB 3.0 and execute in JDeveloper?

Hello guys!
I'm brand new with EJB 3.0.
I would like to know how can I create a @Local EJB and a client in JDeveloper?
It's was ease to create a @Remote EJB and the sample java client, how can I do same to @Local EJB?
I'm using JDeveloper 10.1.3.1.0.3914
Thanks in advance.

Creating a @Local EJB is just as easy, just replace the @Remote by @Local, or checkmark local in the EJB wizard.
You can create a client for a @Local EJB, as local methods aren't available outside the EJB container, that's why they are called local. A test client doesn't run in the ejb container, and therefor cannot access the local ejb methods.
If you want to test the local methods of an ejb, you should create another ejb which calls the first.

A problem determining the JNDI Name of a local EJB with WL 8.1

Hi,
I created a very simple local EJB and deployed it with Weblogic8.1. When I test
it in the Weblogic server admin page, I got the following message:
"The EJB MyLocal has not been tested successfully. There was a problem determining
the JNDI Name of the given bean."
Can anyone help figure out the problem?
Thanks
Henry

Does the ejb have a target server specified?
Does the Ejb have a Jndi binding as specified in the <local-jndi-name></local-jndi-name>
element of weblogic-ejb-jar.xml?
thanks,
Deepak
"Henry" <[email protected]> wrote:
>
>
Hi,
I created a very simple local EJB and deployed it with Weblogic8.1. When
I test
it in the Weblogic server admin page, I got the following message:
"The EJB MyLocal has not been tested successfully. There was a problem
determining
the JNDI Name of the given bean."
Can anyone help figure out the problem?
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Henry

Fail to lookup the local EJB by JNDI in Managed Server

Hi all,
I currently in a deep problem, and can't figure out the cause of it. It just annoying me for week.
In my app, I have binded to the local ejb to JNDI (let's say "ejb/CustomerLocal"), then the client lookup the Local EJB by the following code.
localIc = new InitialContext();
home = (EJBLocalHome)localIc.lookup("ejb/CustomerLocal");
It works well as I do development in the Domain Admin Server. However, when I do the System Integration Test and deploy my app to the managed server, the app fail. It just can't do the Local EJB lookup. Following is the exception.
javax.naming.NameNotFoundException: Unable to resolve 'ejb/CustomerLocal' Resolved ejb[Root exc
eption is javax.naming.NameNotFoundException: Unable to resolve 'ejb.CustomerLocal' Resolved ejb
]; remaining name CustomerLocal'
Does anybody know the cause of it and have solution?
Thanks a lot

Hi,
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I hope it helps.
Regards,
Kuldeep Singh.

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Am using RAD 6.0 IDE and WebSphere6.0 and Ejb 2.1
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DefaultSessionLocal localSession = (DefaultSessionLocal) localHome.create();
String strTest = localSession.welcome(" Hello World ");
System.out.println(" Retrieved ejb method ..." + strTest);
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The CORBA error could suggest your bootstrap port is already being used by another process. Try changing it to something else.
Assuming your webconsole works - its something like this (although off the top of my head can't be sure...)
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'' Unresolved:'local' ; remaining name 'local'
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Hi again,
The exact exception is below,
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Best regards,
Raja
Message was edited by: Raja Nasrallah

Hi Raja,
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Best regards,
Vladimir
PS: Please consider <a href="https://www.sdn.sap.com/sdn/index.sdn?page=crp_help.htm#lostme">rewarding points</a> for helpful answers.

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Hi,
I know It's a bit lazy of me not looking this up in the specs, but I'll give it a go anyway. Does the return value of a Local EJB need to be a serializable object? For my app it would be very convenient to return a org.w3c.dom.Document.
Kind Regards,
Rune Bj�rnstad.

If you use LocalEJB, all params addresses are referencies, so you needn't use serializable interface.

Problems while performing lookup for Local EJBs

Can anybody tell me how can i perform local ejb lookup in Sun app Server 8.0/8.1 ?
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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-jar PUBLIC "-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN" "http://java.sun.com/dtd/ejb-jar_2_0.dtd">
<ejb-jar >
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<session-type>Stateless</session-type>
<transaction-type>Container</transaction-type>
</session>
</enterprise-beans>
<assembly-descriptor></assembly-descriptor>
</ejb-jar>
In sun-ejb-jar.xml I have
<sun-ejb-jar>
<enterprise-beans>
<ejb>
<ejb-name>TeamLeaderBean</ejb-name>
<jndi-name>TeamLeaderBeanLocal</jndi-name>
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</enterprise-beans>
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In the client EJBs code I have used following ways of performing lookup...
ctx.lookup("java:comp/env//TeamLeaderBeanLocal");
ctx.lookup("java:comp/env/ejb/local/TeamLeaderBeanLocal");
ctx.lookup("ejb/TeamLeaderBeanLocal");
Unfortunately none of these performs a successful lookup...???
Can anybody solve my problem?

In order to look up a local EJB from an EJB client you have to add an <ejb-local-ref> element for client EJB. So:
<session>
<ejb-name>MyClientEJB</ejb-name>
<ejb-local-ref>
<ejb-ref-name>ejb/TeamLeaderBeanLocal</ejb-ref-name>
<ejb-ref-type>Session</ejb-ref-type>
<ejb-link>TeamLeaderBeanLocal</ejb-link>
</ejb-local-ref>
</session>
fil
Can anybody tell me how can i perform local ejb
lookup in Sun app Server 8.0/8.1 ?
I have following entries in ejb-jar.xml.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-jar PUBLIC "-//Sun Microsystems,
Inc.//DTD Enterprise JavaBeans 2.0//EN"
"http://java.sun.com/dtd/ejb-jar_2_0.dtd">
<ejb-jar >
<enterprise-beans>
<session >
<ejb-name>TeamLeaderBean</ejb-name>
<local-home>spring.ejb.example.TeamLeaderLocalHome
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<local>spring.ejb.example.TeamLeaderLocal</local>
<ejb-class>spring.ejb.example.TeamLeaderBean</ejb-clas
s>
<session-type>Stateless</session-type>
<transaction-type>Container</transaction-type>
</session>
</enterprise-beans>
<assembly-descriptor></assembly-descriptor>
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<sun-ejb-jar>
<enterprise-beans>
<ejb>
<ejb-name>TeamLeaderBean</ejb-name>
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In the client EJBs code I have used following ways of
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ctx.lookup("java:comp/env//TeamLeaderBeanLocal");
ctx.lookup("java:comp/env/ejb/local/TeamLeaderBeanLoca
l");
ctx.lookup("ejb/TeamLeaderBeanLocal");
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lookup...???
Can anybody solve my problem?

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Any thoughts please?

Why do Servlets not scale as well? Surely they are
more "lightweight" than an EJB (which has all theRMI
overhead), and wouldn't it ultimately be down tothe
underlying app server anyway?Right, but servlets are just HTTP request listeners.
They aren't components, they aren't transactional,
they don't handle persistence, they don't have
naming services, they don't have queuing services.
The EJB container offers you a lot.
With that said, it's not just a choice between
servlets and EJBs. You can use POJOs and avoid EJBs
altogether if you do it right.
Or choose the best of both worlds and mix 'n match as needed.
Noone forces you to choose one over the other (at least not for any technical reasons, I'm not diving into corporate politics here).
My thought was that web services were a better wayto
expose business logic than EJBs, but if there some
solid reason why this isn't the case I like toknow.
Web services - lightweight? Maybe that's true of
REST, but certainly not SOAP. There's an argument
that says services are more heavyweight than EJBs,
because all the XML on the wire is an expensive
protocol.
SOAP is heavy on the network, but it's essentially a rather thin layer on top of other services (if properly architected).
For example we have a SOAP layer exposing a Spring application which proxies an EJB architecture.
Next to that SOAP layer sits a traditional web application (servlets) which itself has a Spring application sitting on top of it for demonstration and testing purposes.
And then there's an SDK allowing direct access to the Spring layer (and thus almost direct access to the EJB layer).
That's the beauty of a true open architecture, each component can be built on top of another and the component underneath can function just fine without it.
Look into Spring:
http://www.springframework.org
It's a lighter alternative to EJBs, and good plumbing
for any Java EE app.While Spring can serve as an alternative for EJB in places where EJB are overkill it's of course not in competition with it.
Spring is a service layer, making use of other technologies (like EJB, like AOP, like ORM) to provide data and other services (like Struts, like JSF, like JSP) to provide that data to requesters.

Error in Workflow Services API acquireTask when using local EJB protocol

Hi,
I have a stateful EJB which calls the workflow services API acquireTask to acquire a task. The task was retrieved using a queryTask API call. However, the acquireTask API fails with an exception at TaskServiceLocalClient.java:1152, as listed below in the log, with no clear message as to why it had failed.
The stateful EJB calls to workflow API using the local EJB protocol.
The version of SOA suite running is 10.1.3.1 with Oracle XE 10.2.0.1 as its dehydration store on Windows XP Professional version 2002.
Just wondering if anyone has encountered this problem or know what might have caused this.
Exception trace is below:
/09/2007 09:23:31 oracle.j2ee.rmi.RMIMessages EXCEPTION_ORIGINATES_FROM_THE_REMOTE_SERVER
WARNING: Exception returned by remote server: {0}
au.com.unico.server.BPELException
at oracle.bpel.services.workflow.task.client.TaskServiceLocalClient.acquireTask(TaskServiceLocalClient.java:1152)
at au.com.unico.server.WorkflowBean.acquireTask(Unknown Source)
at au.com.unico.server.WorkflowBean.fetchTask(Unknown Source)
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.interceptor.joinpoint.EJBJoinPointImpl.invoke(EJBJoinPointImpl.java:35)
at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:119)
at com.evermind.server.ejb.interceptor.system.SetContextActionInterceptor.invoke(SetContextActionInterceptor.java:44)
at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:119)
at com.evermind.server.ejb.interceptor.system.DMSInterceptor.invoke(DMSInterceptor.java:52)
at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:119)
at com.evermind.server.ejb.interceptor.system.TxRequiredInterceptor.invoke(TxRequiredInterceptor.java:50)
at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:119)
at com.evermind.server.ejb.interceptor.system.DMSInterceptor.invoke(DMSInterceptor.java:52)
at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:119)
at com.evermind.server.ejb.InvocationContextPool.invoke(InvocationContextPool.java:55)
at com.evermind.server.ejb.StatefulSessionEJBObject.OC4J_invokeMethod(StatefulSessionEJBObject.java:844)
at Workflow_RemoteProxy_2ooecl0.fetchTask(Unknown Source)
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.rmi.RmiMethodCall.run(RmiMethodCall.java:53)
at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:303)
at java.lang.Thread.run(Thread.java:595)

Hi Nicolas,
It turned out I had the wrong version of "xml.jar" on the classpath. I have swapped the incorrect jar for a correct one and changed my code to use XMLUtil.createDocument(); and now everything runs smoothly.
Thank you very much for your helpful advice.
/emil

Servlet + Local EJBS

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