Author: Serge Pagop
Level: Beginner
Technologies: EJB, Singleton
Summary: The helloworld-singleton
quickstart demonstrates an EJB Singleton Bean that is instantiated once and maintains state for the life of the session.
Target Product: WildFly
Source: https://github.com/wildfly/quickstart/
The helloworld-singleton
quickstart demonstrates the use of an EJB Singleton Bean in WildFly Application Server. It is instantiated once and maintains its state for the life of the session.
The application this project produces is designed to be run on WildFly Application Server 11 or later.
All you need to build this project is Java 8.0 (Java SDK 1.8) or later and Maven 3.3.1 or later. See Configure Maven for WildFly 11 to make sure you are configured correctly for testing the quickstarts.
In the following instructions, replace WILDFLY_HOME
with the actual path to your WildFly installation. The installation path is described in detail here: Use of WILDFLY_HOME and JBOSS_HOME Variables.
For Linux: WILDFLY_HOME/bin/standalone.sh
For Windows: WILDFLY_HOME\bin\standalone.bat
mvn clean install wildfly:deploy
This will deploy target/helloworld-singleton.war
to the running instance of the server.
The application will be running at the following URL: http://localhost:8080/helloworld-singleton/.
This example demonstrates a singleton session bean that maintains state information for 2 variables: Increment A
and Increment B
.
A counter is incremented when you click on the link to the variable name. If you close and restart your browser, or if you have multiple browsers, you can see that the counter always increments the last value. These values are maintained until you restart the server.
To test the singleton bean, click on either Increment A
or Increment B
. The result page will give you the current value of the variable.
mvn wildfly:undeploy
You can also start the server and deploy the quickstarts or run the Arquillian tests from Eclipse using JBoss tools. For general information about how to import a quickstart, add a WildFly server, and build and deploy a quickstart, see Use JBoss Developer Studio or Eclipse to Run the Quickstarts.
If you want to debug the source code of any library in the project, run the following command to pull the source into your local repository. The IDE should then detect it.
mvn dependency:sources