WebLogic Server 6.0 Code Examples, BEA Systems, Inc.

Package examples.ejb20.homeMethods

This example is a package that demonstrates an Enterprise JavaBean written to the EJB 2.0 specification.

See:
          Description

Interface Summary
Account The methods in this interface are the public face of AccountBean.
AccountHome This interface is the home interface for the EJBean AccountBean.
 

Class Summary
AccountBean AccountBean is an EntityBean.
Client This class demonstrates calling a home method on an Entity bean.
 

Exception Summary
ProcessingErrorException ProcessingErrorException is thrown if the caller attempts to withdraw more than a certain preset limit from the account.
 

Package examples.ejb20.homeMethods Description

This example is a package that demonstrates an Enterprise JavaBean written to the EJB 2.0 specification. The example is an entity EJBean called AccountBean.

The example demonstrates:

Before Running the EJB 2.0 Examples

Before you can build and run the EJB 2.0 examples, you must first download the WebLogic Server 6.0 supplement, ejb20.jar, from the BEA product download page. This allows you to use the Enterprise JavaBeans features in the WebLogic Server 6.0 environment. Until you install the ejb20.jar file, you will be unable to build and run the EJB 2.0 examples.

Pre-Built Examples

The EJB 2.0 examples included in the WebLogic Server 6.0 distribution are not shipped pre-built. To run these examples, you must first download ejb20.jar and then build the example following the specific examples instructions.

Client application

The Client application performs these steps:
  1. Looks up a home method on the client
  2. Prints the message from the remote invocation on the Home Method to the client

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

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

As you'll use a database for the persistent storage of the entity EJBean, you'll need to set it up. Note that the persistent storage is completely invisible to the client; the actual storage is handled by the EJBean directly and not the container.

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.

We provide separate build scripts for Windows NT and UNIX:

These scripts build the example and place the files in the correct locations in your WebLogic Server distribution:

Running the build script places the EJB in /config/examples/applications, where it automatically deploys once the server is started. If you are already running the server and build another 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 Deployments.

    A list of deployed EJBs displays.

  4. Choose the appropriate deployment unit from the list.

  5. Select the Target tab in the right-hand pane.

  6. Verify that the EJB is deployed on the examplesServer.

  7. Set the database persistence.

    With database persistence, each instance of an EJBean is written to a row in a table. The table (ejbAccounts) must be created and exist in the database before the example is run. If you are using the evaluation copy of Cloudscape that is included with WebLogic, this table has already been created in the "demo" database. If you're using a database other than Cloudscape, you'll need to create the table in your database using an appropriate SQL statement such as

    "create table ejbAccounts (id varchar(15), bal float, type varchar(15))"

  8. Setup a connection pool in the Administration Console .

    For your convenience, a sample connection pool, called demoPool is included with this example. You can use this connection pool with any of the EJB examples.

    You'll need to:

    In this example, the fileRealm for the access control list (ACL) is pre-configured to allow access for everyone.

    If you need more information about how to use connection pools, read Using WebLogic JDBC: Using connection pools.

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:
    $ java examples.ejb20.homeMethods.Client "t3://WebLogicURL:Port"

    where:

    WebLogicURL
    Domain address of the WebLogic Server
    Port
    Port that is listening for connections (weblogic.system.ListenPort)

  2. If you're running the Client example, you should get output similar to this from the client application:
    Beginning ejb20.exampleshomeMethods.Client...
    
    Here is the message from the remote invocationof the HomeMethod 
    homyMethod: 'Sample: AccountBean.ejbHomeHomyMethod() invoked'
    
    End ejb20.examples.homeMethods.Client...
    

There's more...

Read more about EJB in BEA WebLogic Server Enterprise Java Beans.


Documentation is available at
http://e-docs.bea.com/wls/docs60

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