Lookup an EJB from a different application, deployed on the same server, in JBoss

Question:
I have a web application through which i want to access an EJB which is deployed as a separate appliaction on the same server. How do i do it?
Answer:
In the web.xml of your war(the web application through which you want to access the EJB), have the following entry:

<ejb-ref>

<ejb-ref-name>GiveAnNameByWhichYouWouldLikeToReferTheBeanInYourWebApp</ejb-ref-name>
    <ejb-ref-type>session</ejb-ref-type>
    <home>packageName.ClassNameOfTheHomeObjectOfTheBeanYouWantToRefer</home>
    <remote>packageName.ClassNameOfTheRemoteObjectOfTheBeanYouWantToRefer</remote>
  </ejb-ref>
  

In the jboss-web.xml of your war, have the following entry:

  <ejb-ref>
      <!--The ejb-ref-name should be same as the one given in the web.xml above -->
      <ejb-ref-name>GiveANameByWhichYouWouldLikeToReferTheBeanInYourWebApp</ejb-ref-name>
      <!--Example:somecontext/somejndiName.YouWillFindThisJndiNameInTheJboss.xmlOfTheEJB-->
      <jndi-name>TheJndiNametoWhichTheBeanIsBound</jndi-name>
   </ejb-ref>
   
  

For more info, have a look at the dtds of web.xml (http://java.sun.com/dtd/web-app_2_3.dtd) and jboss-web.xml(http://www.jboss.org/j2ee/dtd)
In your code, do the lookup as:

 
Context ic = new InitialContext();
Object home=ic.lookup("java:comp/env/TheNameThatYouHadGivenInEjb-ref-nameTagOfJbossWeb.xml");

Here’s an example:

web.xml:

<ejb-ref>
    <ejb-ref-name>MyTestBean</ejb-ref-name>
    <ejb-ref-type>session</ejb-ref-type>
    <home>com.test.ejb.MyBeanHome</home>
    <remote>com.test.ejb.MyBeanRemote</remote>
  </ejb-ref>
  

jboss-web.xml:

 <ejb-ref>
   <ejb-ref-name>MyTestBean</ejb-ref-name>
   <jndi-name>myejb/test/MyTestBean</jndi-name>
  </ejb-ref>
 
 

Lookup code:

Context ic = new InitialContext();
  Object ejbHome = ic.lookup("java:comp/env/MyTestBean");

How to create a Queue/Topic in JBoss?

Queues/Topics are known as administered objects and in jboss they can be deployed through ServiceDotXml files. Let’s name our file, myapp-destination-service.xml. The contents of the file should look like:

<?xml version="1.0" encoding="UTF-8"?>

<server>
   <!--My queue, named: myAppQueue -->
  <mbean code="org.jboss.mq.server.jmx.Queue"
  name="jboss.mq.destination:service=Queue,name=myAppQueue">
    <depends optional-attribute-name="DestinationManager">jboss.mq:service=DestinationManager</depends>
  </mbean>
   <!-- My topic, named: myAppTopic -->
  <mbean code="org.jboss.mq.server.jmx.Topic"
  name="jboss.mq.destination:service=Topic,name=myAppTopic">
    <depends optional-attribute-name="DestinationManager">jboss.mq:service=DestinationManager</depends>
  </mbean>
    
  </server>

Place this file in your %JBOSS_HOME%/server/default/deploy directory and start the server.
(Note: If you are using the ‘all’ configuration or the ‘minimal’ configuration then you will have to place this file in the %JBOSS_HOME%/server/all/deploy or %JBOSS_HOME%/server/minimal/deploy directory, as appropriate).

The above queue/topic will be bound to the jndi name: queue/myAppQueue and topic/myAppTopic respectively.

Note:

1) The above file is meant for JBoss-3.2.3. Though there might be slight changes to later versions of JBoss, the basic configuration mechanism remains the same.

2) JBoss also comes with preconfigured queues/topics. These configurations can be found in the jbossmq-destinations-service.xml file which is present in %JBOSS_HOME%/server/default/deploy/jms directory


Update:

For JBoss AS 6.x see this FAQ for more details on how to configure JMS queue/topics

How to enable Garbage Collection (GC) logs

To enable GC logs, the -Xloggc:logFileName option will have to be passed when java command is being executed. Additionally if the detailed log of the GC is required, then an additional -XX:+PrintGCDetails option will have to be passed.

Example: java -Xloggc:D:/log/myLogFile.log -XX:+PrintGCDetails myProg