Welcome to the 3rd in a series of detailed articles on Java EE6 & Wicket. If you haven’t already, please read the following previous articles before continuing.
- Java EE6 & Wicket
- Java EE6 & Wicket - Article #1 - Requirements, Architecture & Resources
- Java EE6 & Wicket - Article #2 – Creating A Backing Datastore And Schema Using MySQL
In this, my 3rd article in this series, we will discuss and demonstrate the generation of the initial GuestBook Web application using the popular NetBeans IDE and the Wicket plugin so please, if you haven’t already, install these two on your development machine before continuing with the rest of this article.
Simple Deployment With Java EE6 And The EJB 3.1 Specification
EE5 frequently required the use of an Enterprise Application Archive for deploying EE Web application. This usually meant having to use multiple projects to deploy even the simplest of EE applications. One of the new features of EE6, sometimes called EAR-less applications, addresses this issue and makes deploying EE6 applications much simpler. Rather than going into the details here, you can read the article Java EE6: EJB3.1 Is a Compelling Evolution, which provides an excellent review of this new feature as well as EE6 in general. The GuestBook Web application that we are now going to create will use this new feature.
OK, lets get started.
Generating The GuestBook Web Application
If you haven’t already, fire up NetBeans.
From the main menu select File | New Project which will open the New Project window.
Select Java Web in the Categories panel and Web Application from the Projects panel and click the Next button.
Enter GuestBook for the project name and click the Next button.
If they aren’t already, select GlassFish Server 3 as the server and Java EE 6 Web as the Java EE version and then click the Next button.
The Wicket plugin added Wicket to the list of frameworks that you can use in Web applications. In the Frameworks panel select Wicket as the framework to use in our application and then click the Finish button.
When we clicked the Finish button NetBeans generated our GuestBook application for us and displays it in the Project panel. If you fully expand the GuestBook node in the Projects panel you will see the following:
Notice the Wicket jars that are listed under the Libraries node in the above image. These jars were contributed by the Wicket plugin when the project was generated. The plugin also contributed a number of files in our com.myapp.wicket package. In essence, the Wicket plugin generated a basic Wicket application for us that we can run right out of the box, so lets do that now.
Run the application by clicking on the Run Main Project icon located on the main tool bar. Your browser should open, if it isn’t already, and a new page will open and display the application’s output as in the following image:
That’s pretty cool considering the minimal effort that was required on our part to get this application up and running at this point.
If you look at the NetBeans Output window you should see a GlassFish Server 3 tab. If you click on this tab you should see that our application has been deployed onto the GlassFish server for us. Also, you should see the following output from Wicket telling us that it is running in development mode.:
Lets ignore the application that the Wicket plugin generated for us for the time being because we now want to turn our attention to adding EJB support to the project. First, though, a little background.
Wicket’s Single Purpose
Wicket has been designed to solve only one specific problem which is to enable component-oriented, programmatic manipulation of markup. In fact, its creators say as much and you can read their own words in their Wicket’s Vision statement here.
As such, Wicket doesn’t provide out-of-the-box support for EJB. Wicket does have, though, many libraries that have been contributed to the project and which provide a lot of the extras that we often need. One of these libraries is the JavaEE Inject Library and it provides the ability to use the @EJB, @PersistenceUnit and @Resource annotations in our Wicket applications. I suggest that you go to the web site hosting the library and read up on the details before continuing with the remainder of this article because it is important to understand not only what the library does for us but how it does it.
Adding The JavaEE Inject Library To Our Project
To keep things simple, I’ve created a compressed file named guestbooktutorialadditionaljars.zip which contains all the jars required by the JavaEE Inject Library and I posted it here. Download the file onto a folder on your machine and extract its content. Then follow these steps to add the jar files to the project:
- In the Projects panel right click on the Libraries node and select Add Jar/Folder to open the Add Jar/Folder window.
- Navigate to the folder on your machine where you extracted the contents of the guestbooktutorialadditionaljars.zip to and select all 3 jar files (important - do not select the zip file itself if it happens to also resides in the same folder, only select the 3 jar files) as pictured below.
- Now click the Open button to close the window and add the 3 jar files to the project.
The result of the above is that NetBeans has added the 3 jar files we selected to our project’s classpath which we can see by looking at the files listed under the Libraries entry in the Projects panel.
We’ve now included all the jars that our project requires and in the next article we’ll discuss and demonstrate adding JPA persistence support to the project. Stay tuned!