shopping-cart: EJB Stateful Session Bean (SFSB) Example

The shopping-cart quickstart demonstrates how to deploy and run a simple Java EE 8 shopping cart application that uses a stateful session bean (SFSB).

What is it?

The shopping-cart quickstart demonstrates how to deploy and run a simple Java EE 8 application that uses a stateful session bean (SFSB) in JBoss Enterprise Application Platform Server. The application allows customers to buy, checkout, and view their cart contents.

The shopping-cart application consists of the following:

A server side component:

This standalone Java EE module is a JAR containing EJBs. It is responsible for managing the shopping cart.
A Java client:

This simple Java client is launched using a main method. The remote client looks up a reference to the server module’s API, via JNDI. It then uses this API to perform the operations the customer requests.

System Requirements

The application this project produces is designed to be run on JBoss Enterprise Application Platform Server 7.2 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.

To run these quickstarts with the provided build scripts, you need the JBoss EAP distribution ZIP. For information on how to install and run the JBoss EAP server, see the Getting Started Guide.

Use of EAP_HOME

In the following instructions, replace EAP_HOME with the actual path to your JBoss EAP installation. The installation path is described in detail here: Use of EAP_HOME and JBOSS_HOME Variables.

Back Up the JBoss EAP Standalone Server Configuration

Before you begin, back up your server configuration file.

If it is running, stop the JBoss EAP server.
Back up the EAP_HOME/standalone/configuration/standalone.xml file.

After you have completed testing this quickstart, you can replace this file to restore the server to its original configuration.

Start the JBoss EAP Standalone Server

Open a terminal and navigate to the root of the JBoss EAP directory.
Start the JBoss EAP server with the default profile by typing the following command.
```
$ EAP_HOME/bin/standalone.sh 
```
Note
For Windows, use the EAP_HOME\bin\standalone.bat script.

Configure the Server

This example quickstart purposely throws a NoSuchEJBException exception when the shopping cart is empty. This is the expected result because method is annotated with @Remove. This means the next invocation after the shopping cart checkout fails because the container has destroyed the instance and it is no longer available. If you do not run this script, you see the following ERROR in the server log, followed by the stacktrace

ERROR [org.jboss.as.ejb3.invocation] (EJB default - 7) WFLYEJB0034: EJB Invocation failed on component ShoppingCartBean for method public abstract java.util.Map org.jboss.as.quickstarts.sfsb.ShoppingCart.getCartContents(): javax.ejb.NoSuchEJBException: WFLYEJB0168: Could not find EJB with id UnknownSessionID [5168576665505352655054705267485457555457535250485552546568575254]

Follow the steps below to suppress system exception logging.

Before you begin, make sure you do the following:
- Back up the JBoss EAP standalone server configuration as described above.
- Start the JBoss EAP server with the standalone default profile as described above.
Review the configure-system-exception.cli file in the root of this quickstart directory. This script sets the log-system-exceptions attribute to false in the ejb3 subsystem in the server configuration file.
Open a new terminal, navigate to the root directory of this quickstart, and run the following command, replacing EAP_HOME with the path to your server:
```
$ EAP_HOME/bin/jboss-cli.sh --connect --file=configure-system-exception.cli
```
Note
For Windows, use the EAP_HOME\bin\jboss-cli.bat script.

You should see the following result when you run the script:
```
The batch executed successfully
```
Stop the JBoss EAP server.

Review the Modified Server Configuration

After stopping the server, open the EAP_HOME/standalone/configuration/standalone.xml file and review the changes.

You should see the following configuration in the ejb3 subsystem.

<log-system-exceptions value="false"/>

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 JBoss EAP server as described above.
Open a terminal and navigate to the root directory of this quickstart.
Type the following command to build the artifacts.
```
$ mvn clean install wildfly:deploy
```

This deploys the shopping-cart/server/target/shopping-cart.jar to the running instance of the server.

You should see a message in the server log indicating that the archive deployed successfully.

You can also check the server console to see information messages regarding the deployment.

INFO  [org.jboss.as.ejb3.deployment] (MSC service thread 1-2) WFLYEJB0473: JNDI bindings for session bean named 'ShoppingCartBean' in deployment unit 'deployment "{artifactId}-server.jar"' are as follows:

  java:global/{artifactId}-server/ShoppingCartBean!org.jboss.as.quickstarts.sfsb.ShoppingCart
  java:app/{artifactId}-server/ShoppingCartBean!org.jboss.as.quickstarts.sfsb.ShoppingCart
  java:module/ShoppingCartBean!org.jboss.as.quickstarts.sfsb.ShoppingCart
  java:jboss/exported/{artifactId}-server/ShoppingCartBean!org.jboss.as.quickstarts.sfsb.ShoppingCart
  java:global/{artifactId}-server/ShoppingCartBean
  java:app/{artifactId}-server/ShoppingCartBean
  java:module/ShoppingCartBean

INFO  [org.jboss.weld.deployer] (MSC service thread 1-4) WFLYWELD0006: Starting Services for CDI deployment: {artifactId}-server.jar
INFO  [org.jboss.weld.deployer] (MSC service thread 1-8) WFLYWELD0009: Starting weld service for deployment {artifactId}-server.jar
INFO  [org.jboss.as.server] (management-handler-thread - 3) WFLYSRV0010: Deployed "{artifactId}-server.jar" (runtime-name : "{artifactId}-server.jar")

Run the Client Application

Now start a client that will access the beans you just deployed.

You can use the terminal from the previous step or open a new one and navigate to the root of the shopping-cart quickstart directory.

Type the following command:

$ mvn exec:java -f client/pom.xml

Investigate the Console Output

You should see the following:

The client sends a remote method invocation to the stateful session bean to buy two 32 GB USB 2.0 Flash Drive and one Wireless Ergonomic Keyboard and Mouse.
The client sends a remote method invocation to get the contents of the cart and prints it to the console.
The client sends a remote method invocation to invoke checkout. Note the checkout() method in the server ShoppingCartBean has the @Remove annotation. This means the container will destroy shopping cart after the call and it will no longer be available.
The client calls getCartContents() to make sure the shopping cart was removed after checkout. This results in a javax.ejb.NoSuchEJBException trace in the server, proving the cart was removed.

On the client console, you should see output similar to:

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
Obtained the remote interface to the shopping cart
Buying a "32 GB USB 2.0 Flash Drive".
Buying another "32 GB USB 2.0 Flash Drive".
Buying a "Wireless Ergonomic Keyboard and Mouse"

Print cart:
1     Wireless Ergonomic Keyboard and Mouse
2     32 GB USB 2.0 Flash Drive

Checkout
Cart was correctly removed, as expected, after Checkout
&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

In the server log, you should see:

INFO  [stdout] (pool-9-thread-8) implementing checkout() left as exercise for the reader!

Undeploy the Quickstart

When you are finished testing the quickstart, follow these steps to undeploy the archive.

Make sure you start the JBoss EAP server as described above.
Open a terminal and navigate to the root directory of this quickstart.
Type this command to undeploy the archive:
```
$ mvn wildfly:undeploy
```

Restore the JBoss EAP Standalone Server Configuration

You can restore the original server configuration using either of the following methods.

You can run the restore-system-exception.cli script provided in the root directory of this quickstart.
You can manually restore the configuration using the backup copy of the configuration file.

Restore the JBoss EAP Standalone Server Configuration by Running the JBoss CLI Script

Start the JBoss EAP server as described above.
Open a new terminal, navigate to the root directory of this quickstart, and run the following command, replacing EAP_HOME with the path to your server:
```
$ EAP_HOME/bin/jboss-cli.sh --connect --file=restore-system-exception.cli
```
Note
For Windows, use the EAP_HOME\bin\jboss-cli.bat script.

This script restores the the log-system-exceptions attribute value to true. You should see the following result when you run the script:

The batch executed successfully

Restore the JBoss EAP Standalone Server Configuration Manually

When you have completed testing the quickstart, you can restore the original server configuration by manually restoring the backup copy the configuration file.

If it is running, stop the JBoss EAP server.
Replace the EAP_HOME/standalone/configuration/standalone.xml file with the backup copy of the file.

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 JBoss EAP 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 Red Hat Developer Studio than the other quickstarts.

Make sure you configure JBoss EAP to suppress system exception logging as described above under Configure the Server. Stop the server at the end of that step.
To deploy the server project, right-click on the shopping-cart-server project and choose Run As –> Run on Server.
To run the client, right-click on the shopping-cart-client project and choose Run As –> Java Application. In the Select Java Application window, choose Client - org.jboss.as.quickstarts.client and click OK. The client output displays in the Console window.
To undeploy the project, right-click on the shopping-cart-server project and choose Run As –> Maven build. Enter wildfly:undeploy for the Goals and click Run.
Make sure you restore the JBoss EAP standalone server configuration when you have completed testing this quickstart.

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