The ejb-remote
quickstart uses EJB and JNDI to demonstrate how to access an EJB, deployed to WildFly, from a remote Java client application.
What is it?
The ejb-remote
quickstart shows how to access an EJB from a remote Java client application. It demonstrates the use of EJB and JNDI in WildFly Application Server.
There are two components to this example:
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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.
-
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 WildFly Application Server 12 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 to Build and Deploy the Quickstarts to make sure you are configured correctly for testing the quickstarts.
Use of WILDFLY_HOME
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.
Start the WildFly Standalone Server
-
Open a terminal and navigate to the root of the WildFly directory.
-
Start the WildFly server with the default profile by typing the following command.
$ WILDFLY_HOME/bin/standalone.sh
NoteFor Windows, use the WILDFLY_HOME\bin\standalone.bat
script.
Install the Quickstart Parent Artifact in Maven
This quickstart requires the quickstart-parent
artifact to be installed in your local Maven repository. To install it, navigate to your QUICKSTART_HOME directory directory and run the following command.
$ cd QUICKSTART_HOME
$ mvn clean install
Build and Deploy the Quickstart
-
Make sure you start the WildFly server as described above.
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Open a terminal and navigate to the root directory of this quickstart.
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Type the following command to build the artifacts.
$ mvn clean install wildfly:deploy
This deploys the ejb-remote/server-side/target/ejb-remote-server-side.jar
to the running instance of the server.
You should see a message in the server log indicating that the archive deployed successfully.
Build and Run the Client Application
-
Navigate to the client subdirectory.
$ cd ../client
-
Compile the client code.
$ mvn clean compile
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Execute the client application within Maven.
$ mvn exec:exec
Investigate the Console Output
When the client application runs, it performs the following steps:
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Obtains a stateless session bean instance.
-
Sends method invocations to the stateless bean to add two numbers, and then displays the result.
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Sends a second invocation to the stateless bean subtract two numbers, and then displays the result.
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Obtains a stateful session bean instance.
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Sends several method invocations to the stateful bean to increment a field in the bean, displaying the result each time.
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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.
-
Open a terminal and navigate to the ejb-remote/client quickstart directory
$ cd client
-
Type the following in the command line:
$ mvn clean package assembly:single
-
You can then run the executable JAR using the
java -jar
command. You will see the same console output as above.$ java -jar target/ejb-remote-client-jar-with-dependencies.jar
Undeploy the Archive
To undeploy the server-side component from the WildFly server:
-
Navigate to the server-side subdirectory:
$ cd ../server-side
-
Type the following command:
$ mvn wildfly:undeploy
Using EJB over HTTP
You can use HTTP as the transport for remote EJB invocations by specifying -Dhttp=true
on both the Maven and command line based execution. This should not change the output, but it will use EJB over HTTP for the invocations. This means that each EJB request maps to a single HTTP request (actually HTTP/2 by default, if it is enabled on the server).
Before you can use it, you need to set up a user on the server as HTTP does not support transparent authentication. The next section describes how to add the authorized application user so you can test the quickstart using HTTP as the transport.
Add the Authorized Application User
This quickstart uses secured management interfaces and requires that you create the following application user to access the running application.
UserName | Realm | Password | Roles |
---|---|---|---|
quickstartUser |
ApplicationRealm |
quickstartPwd1! |
To add the application user, open a terminal and type the following command:
$ WILDFLY_HOME/bin/add-user.sh -a -u 'quickstartUser' -p 'quickstartPwd1!'
Note
|
For Windows, use the WILDFLY_HOME\bin\add-user.bat script.
|
If you prefer, you can use the add-user
utility interactively.
For an example of how to use the add-user utility, see the instructions located here: Add an Application User.
Run the Quickstart in Red Hat JBoss Developer Studio or Eclipse
You can also start the server and deploy the quickstarts or run the Arquillian tests in Red Hat JBoss Developer Studio or 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.
This quickstart consists of multiple projects, so it deploys and runs differently in JBoss Developer Studio than the other quickstarts.
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Install the required Maven artifacts and deploy the server side of the quickstart project.
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Right-click on the ejb-remote-server-side project and choose Run As → Maven Install.
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Right-click on the ejb-remote-server-side project and choose Run As → Run on Server.
-
-
Build and run the client side of the quickstart project.
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Right-click on the ejb-remote-client project and choose Run As → Java Application.
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In the Select Java Application window, choose RemoteEJBClient - org.jboss.as.quickstarts.ejb.remote.client and click OK.
-
The client output displays in the Console window.
-
-
To undeploy the project, right-click on the ejb-remote-server-side project and choose Run As → Maven build. Enter
wildfly:undeploy
for the Goals and click Run.
Debug the Application
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