Creating an EJB 3.0 project and calling it from servlet.

Creating an EJB 3.0 project and calling it from servlet.

WebSphere Integration Developer is the development tool used.

Go to File, New, EJB project. Give the project Name and EAR project name. Click on next and finish.

EAR Project name is the one which will contain your EJB project, or any other project like web project you create later. This EAR project name will contain all the modules and basically required for generating your EAR file containing all the modules.

 

 

Now, we will create the EJB 3.0 stateless session bean

 

Select both the interfaces(Remote and Local)  in the above screen .

Click Next and Finish.

Now, we will create a print method in the EJB class. Rest of the template is created by the development tool.

We add the same method definition to both the interfaces – Local and Remote

 

Now , we create the servlet to call the stateless session EJB created above.

Go to File, New, Dynamic Web Project

 

Add the dynamic web project it to the Same EAR.  So the modules EJB client jar, EJB jar and web module is packaged in one ear file.

 

Click Finish

Right Click the Dynamic Web Project you just created and go to properties, Java EE Module Dependencies and select the JAR module

As we will be calling the EJB remote interface from the servlet, we need to do the above otherwise we will get Class not found exception.

Go to Dynamic Web Project, Servlets. Right click the Servlet and create new servlet

 

And click Finish

In the Servlet class, add a EJB reference using the @EJB annotation as shown below.

Press Control+Shift+O to organize imports.

Note a few items:

1. The @EJB annotation is applied to a member variable that is either a local or remote interface of an EJB.
2. In WebSphere, the default JNDI name of an EJB is set based on the remote or local interface name. As a result, here the @EJB annotation has enough information to deduce the JNDI name.
3. The @EJB annotation works only in a Servlet or EJB bean class. You can't use it from a regular Java class, such as a JSF managed bean or Struts action. These classes must explictly do a JNDI lookup. In WebSphere, the JNDI name of an EJB is same as its remote interface name or ejblocal:LOCAL_INTERFACE_NAME.

Now , we need to deploy the ear

Add the project.

Publish the EAR to server.

In case publish fails. Do a clean, build

Access the URL

http:// hostname: http port/web context root/servlet mapping

http://localhost:9088/asasqsWEB/Sdaas

We have not called the print method of EJB anywhere in the servlet class , we modify the servlet code as below .

Now , we can see the print statements each time you access the servlet URL.