Stateless beans in Java do not keep their state between two calls from the client. So in a nutshell we might consider them as objects with business methods. Each method takes parameters and return results. When the method is invoked some local variables are being created in execution stack. When the method returns the locals are removed ...
I'm in the process of developing a multi-tiered financial processing application in Java using EJB3 (Hibernate + Glassfish for the app and web services layer, Lift on Glassfish for the web UI) and I'm struggling with the question of where to put my business logic. When this project started, our first notion was to put the bulk of our bu...
I have a J2EE 1.3 app that uses EJB 2.1 session and entity beans. Currently this app runs as an EAR file on JBoss. I'd like to switch to the SpringSource dm Application Server because of all the benefits that OSGi provides. Does anyone know if there's an OSGi bundle that can act as an EJB container? Can OpenEJB do this? ...
Our years-old WebLogic J2EE application has a message-driven bean which makes use of a stateless session bean. The MDB onMessage method gets the home interface of the stateless session bean and calls the home interface's create() method to get the actual stateless session bean itself. The code does not attempt to cache the session bean...
I am calling a remote stateless session bean from a J2SE application and would like to cache the reference to the session bean in order to reduce the cost of the lookup. Is this ok? In EJB2 the ServiceLocator pattern was commonly used to cache lookups to remote resources, but EJB3 doesn't have separate EJB Home (which were usually cach...
We have a project with a pretty considerable number of EJB 2 stateless session beans which were created quite a long time ago. These are not the first-line beans which are accessed from our client via RMI, rather they are used by that code to perform specific functions. However, I've come to believe that there's nothing to be gained by h...
Imagine a heavily-used service object that's implemented as an EJB 2.1 SLSB, and that also happens to be thread-safe in itself by virtue of having no state whatsoever. All its public methods are transactional (via CMT), most simply requiring a transaction, but some requiring a new transaction. If I convert this SLSB to a genuine singlet...
I have a EJB defined as this: package com.foo; @Stateless (mappedName="HelloWorld") public class HelloWorldBean implements HelloWorld, HelloWorldLocal .... When it's deployed to Weblogic (WL), it gets the name myBean. I'm not sure if this is important. I try to call the bean with this code: Hashtable ht = new Hashtable(); ht.put(Co...
I have a stateless session bean that contains one public method, several private methods, and some instance level variables. Below is a pseudo code example. private int instanceLevelVar public void methodA(int x) { this.instanceLevelVar = x; methodB(); } private void methodB() { System.out.println(instanceLevelVar); } What I'...
Normally we use singleton instance for business / dao layer. What is the reason behind pooling stateless session beans in case of EJBs? ...
What would a stateless session bean provide over just a regular class that has the same methods? It seems that a stateful session bean can be distributed out of the box and the container will make sure that the state looks the same to clients anywhere. With a stateless session bean what is provided that you would not get with a normal ...
Hi, I am new to EJB. I have a requirement of calling a method of remote stateless bean and setting a value, before calling any method on the same bean. The value set from first method call should be available to second method. I know that a stateless bean can't hold instance variables values for next calls. Is there any alternative to m...
Dear all, I do the following steps with eclipse 3.5 ,JBoss 4.2 ,EJB3 but I face class not found exception 1.compiling this code to foo.jar file package mypackage.foo; import myejbpackage.ejb.fooInterface; class foo implements fooInterface{ @override void helloWorld(){System.out.print("HelloWorld");} } Note that fooInterface ...
L.S. Our DB provider has suggested that we use "unshareable" connections when connecting to their DB. I have a reasonable understanding about the pros/cons of using "unshareable" connections, and our programming model will not cause any issues mentioned in various blog posts. Can anyone give me an idea of how to make our JDBC datasourc...
Hi, 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 i...
I'm sure this is a beginner error... So I have a JEE6 application with entities, facades (implementing the persistence layer) and Stateless Session Beans (EJB3) with Remote interfaces (providing access to the entities via facades). This is working fine. Via the SLSB I can retrieve and manipulate entities. Now, I'm trying to do this fr...
I create an Enterprise Application CustomerApp that also generated two projects CustomerApp-ejb and CustomerApp-war. In the CustomerApp-ejb, I create a SessionBean call CustomerSessionBean.java as below. package com.customerapp.ejb; import javax.ejb.Stateless; import javax.ejb.LocalBean; import javax.persistence.EntityManager; import j...
This is a pretty newbie question- please know I'm aware of that. I have a stateless session bean that needs to load up some data once and cache it locally in a static variable for use by all instances of that bean. The data can be accessed through an entity bean. I'm wondering if its safe to cache the entity instance, or if I should c...
Do I package a stateless session bean in a war file or a ear file for deployment? ...
I've a stateless session bean in an ejb container. If I invoke it from a jsf2 form it works fine, but if I recall the form again it shows me the same data I've inserted before. It happens even if I close and reopen the browser. I must wait several minutes until the form shows empty fields. The stateless session bean is not recreated for ...