EJB 3.0 architecture

EJB 2.1 client does JNDI lookup and gets Remote Home object stub, then asks the Home for a reference to the EJBObject interface and then client can call business method on the bean. Is EJB 3.0 business method invoke procedure same as EJB 2.1?
Thank you,
Dragan.
Edited by: Bobic on Apr 9, 2009 12:08 PM

Hi Dragan,
No, it's much simpler now. There are no longer any Home interfaces. The interface you write is called a business interface and you simply cast the result of the lookup to the business interface and call the business methods. In the case of Stateful session beans, the lookup has
the side-effect of creating a new stateful bean instance.
Note that this only applies to stateful and stateless session beans. The previous EJB 2.x Entity beans weren't changed due to
the introduction of the Java Persistence API.
--ken

Similar Messages

EJB business model architecture + packaging

Hello,
During a development of large Web applications (ERP for example), how to organize the business model (EJB) tier?
I thought of centralizing the business model of the entire application within only one (ejb) module whose each Web module would depend there. What do you think ?
Then, how to package it ? All the modules (Web and business) in the same ear? It would be simplest but not the ideal solution. Because for each update I have to redeploy the entire application.
Thank you.

Thanks for your help mr_jaber.
I would like just to know what is the best way to package and deploy large application to the application server.
Is better to use a single ejb-jar module who contain all buisness logic or split the buisness tier in multiple ejb-jar ?
I know there is the admin_client.jar utility who allows incremental or partial redeployment of EJB modules within an application running in an OC4J instance. This is fine..
So.. I have to put all my modules in a ear archive or is better to deploy Web and EJB modules in standalone mode ?

EJB handle containing t3://null:7001

I'm working on a cluster, using in-memory replication, on SunOs 5.6 (WLS
 5.01 sp1).
 I've 102 stateless session bean, and only 1 stateful.
 The stateful has in weblogic-ejb-home.xml the following:
 <weblogic-ejb-jar>
 <weblogic-enterprise-bean>
 <ejb-name>europortal.architecture.Customer.CustomerSession</ejb-name>
 <caching-descriptor>
 <max-beans-in-cache>100</max-beans-in-cache>
 <idle-timeout-seconds>10</idle-timeout-seconds>
 </caching-descriptor>
 <clustering-descriptor>
 <home-is-clusterable>True</home-is-clusterable>
 <home-load-algorithm>round-robin</home-load-algorithm>
 </clustering-descriptor>
 <jndi-name>europortal.architecture.Customer.CustomerSession</jndi-name>
 </weblogic-enterprise-bean>
 </weblogic-ejb-jar>
 I deploy all of the beans on both the instance of the cluster.
 The jsp using the stateful bean get the following error:
 java.rmi.NoSuchObjectException: Unable to locate
 EJBHome:
 'europortal.architecture.Customer.CustomerSession' on
 server: 't3://null:7001
 at java.lang.Throwable.fillInStackTrace(Native
 Method)
 at
 java.lang.Throwable.fillInStackTrace(Compiled Code)
 at java.lang.Throwable.<init>(Compiled Code)
 at java.lang.Exception.<init>(Compiled Code)
 at java.io.IOException.<init>(Compiled Code)
 at
 java.rmi.RemoteException.<init>(RemoteException.java:56)
 at
 java.rmi.NoSuchObjectException.<init>(NoSuchObjectException.java:50)
 at
 weblogic.ejb.internal.HomeHandleImpl.getEJBHome(HomeHandleImpl.java:68)
 at
 weblogic.ejb.internal.HandleImpl.getEJBObject(Compiled
 Code)
 at
 europortal.architecture.Customer.CustomerSessionWrapper.getFreePagesServiceL
 abel(CustomerSessionWrapper.java:261)
 at
 jsp_servlet._NASApp._EPApps._priveligeManager._jspService(Compiled
 Code)
 at
 weblogic.servlet.jsp.JspBase.service(Compiled Code)
 at
 weblogic.servlet.internal.ServletStubImpl.invokeServlet(Compiled
 Code)
 at
 weblogic.servlet.internal.ServletStubImpl.invokeServlet(Compiled
 Code)
 at
 weblogic.servlet.internal.RequestDispatcherImpl.include(Compiled
 Code)
 at
 weblogic.servlet.internal.RequestDispatcherImpl.include(Compiled
 Code)
 at EPApps.mainProcess.service(Compiled Code)
 at
 javax.servlet.http.HttpServlet.service(Compiled Code)
 at
 weblogic.servlet.internal.ServletStubImpl.invokeServlet(Compiled
 Code)
 at
 weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImp
 l.java:742)
 at
 weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImp
 l.java:686)
 at
 weblogic.servlet.internal.ServletContextManager.invokeServlet(ServletContext
 Manager.java:247)
 at
 weblogic.socket.MuxableSocketHTTP.invokeServlet(MuxableSocketHTTP.java:363)
 at
 weblogic.socket.MuxableSocketHTTP.execute(Compiled
 Code)
 at weblogic.kernel.ExecuteThread.run(Compiled
 Code),
 while using the handle of the ejb and, finding it == null, tries to start
 again from the lookup.
 I've serialized the handle on a file, as soon as it was created, and inside
 it I can read the following:
 t3://null:7001 (it's not ASCII, but you can read it)
 It looks like an error in getting the address of the server...
 But everything works fine when I use a single WLS instance without cluster.
 Anyone can help?
 I enclose the code (CustomerSessionWrapper.java)
 [CustomerSessionWrapper.java]


I checked with the developer on this and he says that you forgot to set
 weblogic.cluster.dnsName property. Please refer to the ejb documentation for more info on this.
 - Prasad
 Luca Relandini wrote:
 > I'm working on a cluster, using in-memory replication, on SunOs 5.6 (WLS
 > 5.01 sp1).
 > I've 102 stateless session bean, and only 1 stateful.
 > The stateful has in weblogic-ejb-home.xml the following:
 > <weblogic-ejb-jar>
 > <weblogic-enterprise-bean>
 > <ejb-name>europortal.architecture.Customer.CustomerSession</ejb-name>
 > <caching-descriptor>
 > <max-beans-in-cache>100</max-beans-in-cache>
 > <idle-timeout-seconds>10</idle-timeout-seconds>
 > </caching-descriptor>
 > <clustering-descriptor>
 > <home-is-clusterable>True</home-is-clusterable>
 > <home-load-algorithm>round-robin</home-load-algorithm>
 > </clustering-descriptor>
 > <jndi-name>europortal.architecture.Customer.CustomerSession</jndi-name>
 > </weblogic-enterprise-bean>
 > </weblogic-ejb-jar>
 >
 > I deploy all of the beans on both the instance of the cluster.
 > The jsp using the stateful bean get the following error:
 >
 > java.rmi.NoSuchObjectException: Unable to locate
 > EJBHome:
 > 'europortal.architecture.Customer.CustomerSession' on
 > server: 't3://null:7001
 > at java.lang.Throwable.fillInStackTrace(Native
 > Method)
 > at
 > java.lang.Throwable.fillInStackTrace(Compiled Code)
 > at java.lang.Throwable.<init>(Compiled Code)
 > at java.lang.Exception.<init>(Compiled Code)
 > at java.io.IOException.<init>(Compiled Code)
 > at
 > java.rmi.RemoteException.<init>(RemoteException.java:56)
 > at
 > java.rmi.NoSuchObjectException.<init>(NoSuchObjectException.java:50)
 > at
 > weblogic.ejb.internal.HomeHandleImpl.getEJBHome(HomeHandleImpl.java:68)
 > at
 > weblogic.ejb.internal.HandleImpl.getEJBObject(Compiled
 > Code)
 > at
 > europortal.architecture.Customer.CustomerSessionWrapper.getFreePagesServiceL
 > abel(CustomerSessionWrapper.java:261)
 > at
 > jsp_servlet._NASApp._EPApps._priveligeManager._jspService(Compiled
 > Code)
 > at
 > weblogic.servlet.jsp.JspBase.service(Compiled Code)
 > at
 > weblogic.servlet.internal.ServletStubImpl.invokeServlet(Compiled
 > Code)
 > at
 > weblogic.servlet.internal.ServletStubImpl.invokeServlet(Compiled
 > Code)
 > at
 > weblogic.servlet.internal.RequestDispatcherImpl.include(Compiled
 > Code)
 > at
 > weblogic.servlet.internal.RequestDispatcherImpl.include(Compiled
 > Code)
 > at EPApps.mainProcess.service(Compiled Code)
 > at
 > javax.servlet.http.HttpServlet.service(Compiled Code)
 > at
 > weblogic.servlet.internal.ServletStubImpl.invokeServlet(Compiled
 > Code)
 > at
 > weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImp
 > l.java:742)
 > at
 > weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImp
 > l.java:686)
 > at
 > weblogic.servlet.internal.ServletContextManager.invokeServlet(ServletContext
 > Manager.java:247)
 > at
 > weblogic.socket.MuxableSocketHTTP.invokeServlet(MuxableSocketHTTP.java:363)
 > at
 > weblogic.socket.MuxableSocketHTTP.execute(Compiled
 > Code)
 > at weblogic.kernel.ExecuteThread.run(Compiled
 > Code),
 >
 > while using the handle of the ejb and, finding it == null, tries to start
 > again from the lookup.
 > I've serialized the handle on a file, as soon as it was created, and inside
 > it I can read the following:
 > t3://null:7001 (it's not ASCII, but you can read it)
 > It looks like an error in getting the address of the server...
 >
 > But everything works fine when I use a single WLS instance without cluster.
 > Anyone can help?
 > I enclose the code (CustomerSessionWrapper.java)
 >
 > Name: CustomerSessionWrapper.java
 > CustomerSessionWrapper.java Type: Java file (application/x-unknown-content-type-VisualCafeFile.Document)
 > Encoding: x-uuencode

Using HashMaps in an EJB

Ok this is the second time Im posting this problem. Last time I posted all the details and it may have been more general. This time I will be more specific. The following are the requirement that we were given for a school assignment,
Develop a prototype software module to implement a messenger service. Messaging
Systems consist of one Messaging server and several clients. Message can differ from a simple text message to a complex object like an Image. System should include following components.
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P.S - The *** indicate 'ing. The forum seems to sensor those words.
Message was edited by:
jomanlk

WELL I gone through your code in the link
http://forum.java.sun.com/thread.jspa?threadID=5138929&messageID=9509475#9509475
Well thats the important parts of the code. it works fine when I send >simple messages but when I try out the HashMap the servlet is >displayed but no messages are sent to the queue. It would be great if >anyone could help. The reason is simple;
THE HASHMAP CONTAIN NULL VALUES AND YOU ARE SENDING NULL TO THE JMS SO NO OUTPUT.
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
String title=request.getParameter("title");
     System.out.println("TITLE IS     :"+title);
String body=request.getParameter("body");
     System.out.println("BODY IS     :"+body);
HashMap hm = new HashMap();
//hm.put("title", request.getParameter("title"));
//hm.put("body", request.getParameter("body"));
     hm.put("title",title );
hm.put("body", body);
if ((title!=null) && (body!=null)) {
try {
Connection connection = connectionFactory.createConnection();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
MessageProducer messageProducer = session.createProducer(queue);
ObjectMessage message = session.createObjectMessage();
// here we create NewsEntity, that will be sent in JMS message
NewsEntity e = new NewsEntity();
e.setTitle(title);
e.setBody(body);
e.setHm(hm);
message.setObject(e);
messageProducer.send(message);
messageProducer.close();
connection.close();
// response.sendRedirect("ListNews");
} catch (JMSException ex) {
ex.printStackTrace();
try out this code this modified code and allot some dukes if you succeed best of luck :))

Monitor socket with thread in WebLogic

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www.orbism.com

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What is the reason/inspiration/motivation behind the EJB architecture the way it is?
Define two remote interfaces, one for the life cycle methods (Home) and one for the
business methods (Remote) and a bean class that is shielded from the client.
The client accessing the home interface to get a remote reference and so on.....

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The main aim of EJB spec is to differentiate between the different role players.
For eg.
1. the application server providers provide support the EJB containers.
2. The EJB container providers support for Enterprise Bean developers.
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T

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EJB Structure/Architecture

Hi I'm going to begin a new project here im my company, and we have already a project running with EJB, the problem is that this other project was defined by another person here and I disagre with somethings but I would like to hear you all to see if these things I'm talking about is really wrong or not.
Ok, lets start off, in the server side everything is defined exactly like usually, we have sessionBean implementing the right interface and a localHome and remoteHome an EntityBean very well written, but in the client side that is my point, there is a definition of a client and a helper that I think is totally wrong (or not, I don't know).
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I don't think it should be like this but I don't think that the way this guy defined the things would be the better way, please I need suggestions, points and so on. If you need
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Thanks a lot
Dorileo

Ok, lets start off, in the server side everything is
defined exactly like usually, we have sessionBean
implementing the right interface and a localHome and
remoteHome an EntityBean very well written, but in
the client side that is my point, there is a
definition of a client and a helper that I think is
totally wrong (or not, I don't know).It sounds like a BusinessDelegate, which is not wrong at all.
http://java.sun.com/blueprints/corej2eepatterns/Patterns/BusinessDelegate.html

Entity EJB Relationships Architectural Question

I need to create a hierarchy of simple objects. I will call my object
"Part" for simplicity. I have two Oracle tables to maintain my Part
hierarchy. The first table contains the detail for the part: number and
name. The second table maintains the relationship: parent_number and
child_number. I built Entity EJBs with CMP for both tables, but I don't
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Thanks Slava,
You deserve more than a free trip to a conference for the time and effort
that you put into this board. I think you should be able to write this off
as a charitable contribution on your taxes. If you need someone to sign the
receipt, just let me know.
Anyway, back to my hierarchy issue(s). I found some information that
weblogic will set-up this kind of many-to-many relationship for you if you
set it up correctly in the weblogic-cmp-rdbms-jar.xml and the ejb-jar.xml.
So I went through the DTDs, but despite the examples the help is extremely
vague. Has anyone done this? Could anyone recommend where I could find
something more on the topic (books, magazine articles, online documentation,
code, etc)?
Thanks again,
Thomas A. Valletta
"Slava Imeshev" <[email protected]> wrote in message
news:3ec552f9$[email protected]..
Hi Thomas,
"Thomas A. Valletta" <[email protected]> wrote in message
news:[email protected]..
I need to create a hierarchy of simple objects. I will call my object
"Part" for simplicity. I have two Oracle tables to maintain my Part
hierarchy. The first table contains the detail for the part: number and
name. The second table maintains the relationship: parent_number and
child_number. I built Entity EJBs with CMP for both tables, but I don't
know if that is the "best practices" approach. If it is, how do I
define
the relationships (EJB 2.0)? If it is not, how would you build it?The best approach is the one that works for you. If the
combination of two beans works, leave it as is and
go ahead with next tasks.
Regards,
Slava Imeshev

EJB 3.0 architecture

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