temperature-converter

temperature-converter: Stateless Session EJB

Author: Bruce Wolfe, Werner Keil Level: Beginner Technologies: CDI, JSF, SLSB EJB, JSR 385 Summary: Demonstrates a stateless session bean

What is it?

Based on quickstarts to demonstrate Java EE and a few additional technologies.

The temperature-converter example demonstrates the use of an EJB 3.1 Stateless Session Bean (SLSB) and CDI, accessed using a JSF, converting temperatures via JSR 385, deployed to a compatible Java EE container like Wildfly.

These are the steps that occur:

1. The user interface is a JSF page that asks for a temperature and a scale (Kelvin or Celsius).
2. When you click on Convert, the temperature string is passed to the TemperatureConverter controller (managed) bean.
3. The managed bean then invokes the convert() method of the injected TemperatureConvertEJB (notice the field annotated with @Inject).
4. The response from TemperatureConvertEJB is stored in the temperature field of the managed bean.
5. The managed bean is annotated as @SessionScoped, so the same managed bean instance is used for the entire session.

System requirements

All you need to build this project is Java 8.0 or above, running Indriya and Maven 3.0 or better.

The application this project produces is designed to be run in a Java EE (8) compatible environment like Wildfly 13 and above or Thorntail.

Configure Maven

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

Wildfly

Start Wildfly with the Web Profile

1. Open a command line and navigate to the root of the JBoss server directory.

2. The following shows the command line to start the server with the web profile:

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

Build and Deploy the Quickstart

NOTE: The following build command assumes you have configured your Maven user settings. If you have not, you must include Maven setting arguments on the command line. See Build and Deploy the Quickstarts for complete instructions and additional options.

1. Make sure you have started the JBoss Server as described above.

2. Open a command line and navigate to the root directory of this quickstart.

3. Type this command to build and deploy the archive:

    mvn clean package jboss-as:deploy // older JBoss installations
   

   or

    mvn clean package jboss:deploy // WildFly installations
   

4. This will deploy target/temperature-converter.war to the running instance of the server.

Access the application

The application will be running at the following URL: http://localhost:8080/temperature-converter/.

You will be presented with a simple form for temperature conversion.

1. Optionally, Select a scale: Celsius or Kelvin.
2. Enter a temperature.
3. Press the Convert button to see the results.

Undeploy the Archive

1. Make sure you have started the JBoss Server as described above.

2. Open a command line and navigate to the root directory of this quickstart.

3. When you are finished testing, type this command to undeploy the archive:

    mvn package jboss-as:undeploy
   

Thorntail

Build and Run the Quickstart

1. Open a command line and navigate to the root directory of this quickstart.

2. Type this command to build and deploy the archive:

    mvn clean thorntail:run -Pthorntail
   

Access the application

The application will be running at the following URL: http://localhost:8080/.

Undeploy the Archive

Press Ctrl+C to kill the process. Note, on some OS especially Windows it may be necessary to kill it more explicitly due to problems described under https://stackoverflow.com/questions/53258699/thorntail-not-exiting-gracefully

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