Package examples.ejb11.subclass

This example demonstrates subclassing an Enterprise JavaBean.

See:
Description

Interface Summary

Child	The methods in this interface are the public face of ChildBean.
ChildHome	This interface is the home interface for the ChildBean.java, which in WebLogic is implemented by the code-generated container class ChildBeanC.
Parent	The methods in this interface are the public face of ParentBean.

Class Summary

ChildBean	ChildBean is a stateless SessionBean.
Client	This class illustrates using an EJBean that subclasses from a another bean.
ParentBean	ParentBean is a stateless SessionBean.

Package examples.ejb11.subclass Description

This example demonstrates subclassing an Enterprise JavaBean.

The example is a stateless session EJB called ChildBean that extends the ParentBean class.

The example demonstrates:

• Usage of a session EJBean
• Using subclassing to simplify related bean classes
• ParentBean class contains methods that are either unique to the Parent class or that are overloaded by methods in the ChildBean class

The Client application performs these steps:

1. Creates a ChildBean
2. Calls a method that's overloaded by the ChildBean class
3. Calls a method that's inherited from the ParentBean class
4. Calls a method that only exists in ChildBean
5. Removes ChildBean

The package demonstrates how you can use inheritance to simplify the design of beans where there is common code shared by related beans. See the Child bean example for how this is used.

To get the most out of this example, first read through the source code files.

• Client applications
  Client.java

  Deployment

  ejb-jar.xml

  weblogic-ejb-jar.xml

  Interfaces

  Parent.java

  Child.java

  ChildHome.java

  Server (EJB)

  ParentBean.java

  ChildBean.java

Start with the XML deployment files ejb-jar.xml and weblogic-ejb-jar.xml to find the general structure of the EJBs, which classes are used for the different objects and interfaces, then look at the client code see how the application works.

Pre-Built Examples

This EJB 1.1 example is not shipped pre-built. Before you can run this example, you must first build it following the instructions in Build the example.

These three sections cover what to do:

1. Build the example
2. Configure the server
3. Run the example

Build the example

Set up your development shell, as described in Setting up your environment for building and running the examples.

We provide a build script for you to build the example:

The build script is build.xml.

Run the build script using the following Java ant command:

prompt> ant

The script build the example and place the files in the correct locations in your WebLogic Server distribution:

• Client.jar file: in SAMPLES_HOME\server\stage\examples\clientclasses
• EJBean: in SAMPLES_HOME\server\config\examples\applications\ejb11_subclass.ear

Running the build script places the EJB in the SAMPLES_HOME\samples\server\config\examples\%applications% directory, where it automatically deploys once the server is started. If you are already running the server and then build the EJB, it is automatically placed in this directory and instantly deployed.

Additional information on using the build scripts is found in Building Enterprise JavaBean examples

Configure the server

1. Start the WebLogic Server.

2. Start the Administration Console.

3. Click to expand the Deployments node in the left pane and select EJB.

   A list of deployed EJBs displays in the left pane.

4. Choose the EJB that you want to deploy from the list of deployment units.

5. On the Edit EJB Descriptor page in the right pane, select the Targets tab.

6. Verify that the EJB is deployed on the examplesServer. The examplesServer should be listed in the Chosen column.

Run the example

1. Run the client in a separate command line window. Set up your client as described in Setting up your environment, and then run the client by entering:

     prompt> ant run  

2. If you're running the Client example, you should get output similar to this from the client application:

   Beginning subclass.Client...
   
   Creating ChildBean...
   
   Calling method overloaded by ChildBean class
   Hello from the ChildBean
   Calling method inherited by ChildBean class
   ParentBean's nonOverloadedMethod called 
   Calling method that only exists in ChildBean class
   ChildBeans childOnlyMethod called
   Removing ChildBean...
   
   Ending subclass.Client...
   
   

   There's more...

   Read more about EJB in BEA WebLogic Server Enterprise JavaBeans.