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ejb-remote: Remote EJB Client Example

What is it?

This example shows how to access an EJB from a remote Java client application. It demonstrates the use of EJB 3.1 and JNDI in Red Hat JBoss Enterprise Application Platform.

There are two components to this example:

  1. A server side component:

    The server component is comprised of a stateful EJB and a stateless EJB. It provides both an EJB JAR that is deployed to the server and a JAR file containing the remote business interfaces required by the remote client application.

  2. A remote client application that accesses the server component.

    The remote client application depends on the remote business interfaces from the server component. This application looks up the stateless and stateful beans via JNDI and invokes a number of methods on them.

Each component is defined in its own standalone Maven module. The quickstart provides a top level Maven module to simplify the packaging of the artifacts.

System requirements

The application this project produces is designed to be run on Red Hat JBoss Enterprise Application Platform 6.1 or later.

All you need to build this project is Java 6.0 (Java SDK 1.6) or later, Maven 3.0 or later.

Configure Maven

If you have not yet done so, you must Configure Maven before testing the quickstarts.

Start the JBoss EAP Server

  1. Open a command prompt and navigate to the root of the JBoss EAP directory.
  2. The following shows the command line to start the server:

     For Linux:   EAP_HOME/bin/standalone.sh
     For Windows: EAP_HOME\bin\standalone.bat
    

Build and Deploy the Quickstart

Since this quickstart builds two separate components, you can not use the standard Build and Deploy commands used by most of the other quickstarts. You must follow these steps to build, deploy, and run this quickstart.

  1. Make sure you have started the JBoss EAP server. See the instructions in the previous section.
  2. Open a command prompt and navigate to the ejb-remote quickstart directory
  3. Build and install the server side component:
    • Navigate to the server-side subdirectory:

      cd server-side

    • Build the EJB and client interfaces JARs and install them in your local Maven repository.

        mvn clean install        
      
    • Deploy the EJB JAR to your server. This maven goal will deploy server-side/target/jboss-ejb-remote-server-side.jar. You can check the JBoss EAP server console to see information messages regarding the deployment.

        mvn jboss-as:deploy
      
  4. Build and run the client application
    • Navigate to the server-side subdirectory:

        cd ../client
      
    • Compile the client code

        mvn clean compile
      
    • Execute the client application within Maven

        mvn exec:exec
      

Investigate the Console Output

When the client application runs, it performs the following steps:

  1. Obtains a stateless session bean instance.
  2. Sends method invocations to the stateless bean to add two numbers, and then displays the result.
  3. Sends a second invocation to the stateless bean subtract two numbers, and then displays the result.
  4. Obtains a stateful session bean instance.
  5. Sends several method invocations to the stateful bean to increment a field in the bean, displaying the result each time.
  6. Sends several method invocations to the stateful bean to decrement a field in the bean, displaying the result each time.

The output in the terminal window will look like the following:

  Obtained a remote stateless calculator for invocation
  Adding 204 and 340 via the remote stateless calculator deployed on the server
  Remote calculator returned sum = 544
  Subtracting 2332 from 3434 via the remote stateless calculator deployed on the server
  Remote calculator returned difference = 1102
  Obtained a remote stateful counter for invocation
  Counter will now be incremented 5 times
  Incrementing counter
  Count after increment is 1
  Incrementing counter
  Count after increment is 2
  Incrementing counter
  Count after increment is 3
  Incrementing counter
  Count after increment is 4
  Incrementing counter
  Count after increment is 5
  Counter will now be decremented 5 times
  Decrementing counter
  Count after decrement is 4
  Decrementing counter
  Count after decrement is 3
  Decrementing counter
  Count after decrement is 2
  Decrementing counter
  Count after decrement is 1
  Decrementing counter
  Count after decrement is 0

Logging statements have been removed from this output here to make it clearer.

Build and Run The Quickstart as an Executable JAR

The remote client application can also be built as a standalone executable JAR with all of its dependencies.

  1. Open a command prompt and navigate to the ejb-remote/client quickstart directory

     cd client
    
  2. Type the following in the command line:

     mvn clean assembly:assembly
    
  3. You can then run the executable JAR using the java -jar command. You will see the same console output as above.

     java -jar target/jboss-ejb-remote-client-jar-with-dependencies.jar 
    

Undeploy the Archive

To undeploy the server side component from the JBoss EAP server:

  1. Navigate to the server-side subdirectory:

     cd ../server-side
    
  2. Type the following command:

     mvn jboss-as:undeploy
    

Run the Quickstart in JBoss Developer Studio or Eclipse

You can also start the server and deploy the quickstarts from Eclipse using JBoss tools. For more information, see Use JBoss Developer Studio or Eclipse to Run the Quickstarts

Debug the Application

If you want to debug the source code or look at the Javadocs of any library in the project, run either of the following commands to pull them into your local repository. The IDE should then detect them.

    mvn dependency:sources
    mvn dependency:resolve -Dclassifier=javadoc

Recent Changelog

  • Apr 11, 2014(Sande Gilda):Bz1086883 Update Product Version metadata to include EAP 6.3
  • Mar 12, 2014(Sande Gilda):Bz1074530 replace JBOSS_HOME with EAP_HOME
  • Mar 2, 2014(Sande Gilda):Bz1025766 Replace JBoss with JBoss EAP
  • Feb 14, 2014(Sande Gilda):Replace JDBS instructions with shared resource
  • Jan 28, 2014(Sande Gilda):JDF 602 Part 2 of changes to move common instructions to a shared repository. This commit contains the Maven Configuration link changes
  • Dec 16, 2013(Sande Gilda):JDF 577 Replace command line with command prompt when referring to a terminal
  • Nov 20, 2013(Sande Gilda):Bz1032747 fix JAR name for ejb remote quickstart java jar client test
  • Nov 8, 2013(Sande Gilda):Bz1028448 Add spaces to end of metadata so it renders with a line break in HTML
  • Oct 2, 2013(Sande Gilda):README add Product Versions metadata remove versions in text remove temp repo from settings.xml
  • Sep 24, 2013(Sande Gilda):Remove references to web profile
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