Package examples.ejb20.homeMethods

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

The example demonstrates:

• Usage of an entity EJBean written to the EJB 2.0 specification
• Bean-managed persistence; the code in the EJBeandirectly accesses the data storage
• Using application-defined exceptions
• Client application

Pre-Built Examples

The EJB 2.0 examples included in the WebLogic Server 6.1 distribution are not shipped pre-built. To run these examples, you must build the example following the specific examples instructions.

Client application

TheClientapplication 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 sourcecode files.

• Client applications
  Client.java

  Interfaces

  Account.java

  AccountHome.java

  Deployment

  ejb-jar.xml

  weblogic-ejb-jar.xml

  weblogic-cmp-rdbms-jar.xml

  Exception

  ProcessingErrorException.java

  Server (EJBean)

  AccountBean.java

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 thecontainer.

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 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:
$ant

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

• Client files: in /config/examples/clientclasses/
• EJBean: in /config/examples/applications/ejb20_homeMethods.jar

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 scriptsis 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 arow in a table. The table (ejbAccounts) must be created and exist in the databasebefore the example is run. If you are using the evaluationcopy of Cloudscape that is included with WebLogic, this tablehas already been created in the "demo" database. If you're using a database other than Cloudscape, you'll need tocreate the table in your database using an appropriate SQLstatement 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:

   • Make sure that the connection is available for use.

     # In the left-hand pane, expand the Services node and choose JDBC.

     # Click demoPool to display the configuration information in the right-hand pane.

     # Click the Connections tab and review the attribute settings to make sure that they are correct.

   In particular, make sure that the URL and Driver Classname attributes are set for the correct database. This example connection pool is pre-configured for Cloudscape. For other databases, you will need to set an appropriate url and driver, such as

   	  URL=jdbc:weblogic:oracle,\	  DriverName=weblogic.jdbc.oci.Driver,\

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

   If you need more information about how to use connection pools, read UsingWebLogic 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 WebLogicServer Enterprise Java Beans.