The ejb-throws-exception
quickstart demonstrates how to throw and handle exceptions across JARs in an EAR.
What is it?
The ejb-throws-exception
quickstart extends the ejb-in-ear quickstart and demonstrates how to handle exceptions across JARs in an EAR deployed to WildFly Application Server. In this quickstart, an EJB in the EJB JAR throws a custom exception. The web application in the client JAR catches the exception and displays it in a nicely formatted message. The EAR contains: JSF WAR, an EJB JAR and a client library JAR containg classes that both the WAR and EJB JAR use.
This example consists of the following Maven projects, each with a shared parent.
Project | Description |
---|---|
|
This project contains the EJB code and can be built independently to produce the JAR archive.
|
|
This project contains the JSF pages and the CDI managed bean.
|
|
This project builds the EAR artifact and pulls in the ejb, web, and client artifacts. |
|
This project builds the ejb-api library artifact which is used by the ejb, web, as well as remote client artifacts.
|
The root pom.xml
builds each of the subprojects in the above order and deploys the EAR archive to the server.
The example follows the common "Hello World" pattern, using the following workflow.
-
A JSF page asks for a user name.
-
On clicking Say Hello, the value of the Name input text is sent to a managed bean named
GreeterBean
. -
On setting the name, the
Greeter
invokes theGreeterEJB
, which was injected to the managed bean. Notice that the field is annotated with@EJB
. -
The EJB responds with Hello <name> or throws an exception if the name is empty or null.
-
The response or exception’s message from invoking the
GreeterEJB
is stored in a field (response) of the managed bean. -
The managed bean is annotated as
@RequestScoped
, so the same managed bean instance is used only for the request/response.
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.
Build and Deploy the Quickstart
-
Make sure you start the WildFly 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 ejb-throws-exception/ear/target/ejb-throws-exception.ear
to the running instance of the server.
You should see a message in the server log indicating that the archive deployed successfully.
Access the Application
The application will be running at the following URL http://localhost:8080/ejb-throws-exception/.
Enter a name in the input field Name and click the Say Hello button to see the response.
The Response output text will display the response from the EJB. If the Name input text box is not empty, then the Response output text will display Hello <name> If the Name input text box is empty, then the Response output text will display the message of the exception throw back from the EJB.
Undeploy the Quickstart
When you are finished testing the quickstart, follow these steps to undeploy the archive.
-
Make sure you start the WildFly 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
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.
For this quickstart, follow the special instructions to build Quickstarts Containing an EAR.
-
Right-click on the ejb-throws-exception-ear subproject, and choose Run As → Run on Server.
-
Choose the server and click Finish.
-
This starts the server, deploys the application, and opens a browser window that accesses the running application.
-
To undeploy the project, right-click on the ejb-throws-exception-ear 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