JDBC Sequence EJB Sample

JDBC Sequence Sample

This sample demonstrates creating unique identification numbers using EJBs. You can use these techniques when you create an entity bean that requires a unique primary key. This sample uses a container-managed persistence based entity bean with a JDBC connection pool to show using a database table to create unique keys. The table and ranges for the keys are defined in the deployment descriptor.

Main Directory Location

The following directory contains the Java source files and XML-based deployment descriptors.

Windows NT:

$TUXDIR\samples\j2ee\ejb\sequence\jdbc

UNIX:

$TUXDIR/samples/j2ee/ejb/sequence/jdbc

A common build script is provided for all the EJB samples and it can be found in the following directory:

Windows NT:

$TUXDIR\samples\j2ee\ejb

Unix:

$TUXDIR/samples/j2ee/ejb

Files

The following table lists and describes all the files for this sample application:


File	Description
`ejb-jar.xml`	The XML deployment descriptor file used to add the bean to the EJB container
`weblogic-ejb-extensions.xml`	The file containing the WLE extensions to the deployment descriptor DTD
`Client.Java`	The Java source code for the client
`AutoAccountBean.java`	The Java source code for the container-managed entity bean. This class contains the business logic method implementations and methods required by EJB 1.1 specification.
`AutoAccount.java`	The Java source code for the Remote interface of the `AutoAccountBean` class
`AutoAccountHome.java`	The Java source code for the Home interface of the `AutoAccountBean` class
`AutoAccountPK.java`	The primary key for the EJB
`ProcessingErrorException.java`	Application-specific exception thrown by the `AutoAccountBean` class for business methods.

Utility Files

The following table lists and describes the utility files for this sample application. These files are generated based on the WLE installation environment. Because a common build script is provided for all the EJB samples, instructions to build and execute the samples are provided later in Building and Running the EJB Sample Applications. The following files generated in the same directory as where the source files are found.


File	Description
`runme.cmd`	The Windows NT batch file that contains commands to set the environment, boot the server, and execute the client for this sample
`runme.ksh`	The UNIX Korn shell script that contains commands to boot the server and execute the client for this sample
`run_client.cmd`	The batch file to run the client on Windows NT systems
`run_client.ksh`	The script file to run the client only on UNIX systems
`setenv.cmd`	The batch file to set the necessary environment variables on Windows NT systems
`setenv.ksh`	The script file to set the necessary environment variables on UNIX systems
`ubbconfig`	The WLE server configuration file to be used on UNIX systems
`ubbconfig.nt`	The WLE server configuration file to be used on Windows NT systems
`ejb_sequence_jdbc.jar`	The ejb-jar file that contains the source file classes, the container-specific class files generated by the `ejbc` command, and the deployment descriptor files. This is the ejb-jar file that is deployed on the WLE server.

Building and Running the Sample

Before you build and run the JDBC sequence sample, make sure you do the following:

Create the table in your database using SQL statements such as the following:

                "create table ejbAccounts (id varchar(15), bal float, type varchar(15))"
                "create table idGenerator (tablename varchar(32), maxKey int)"

Edit the weblogic-ejb-extensions.xml file to indicate the appropriate database information. The locations within the weblogic-ejb-extensions.xml file that you need to edit are identified by the following comments:
```
         *** DATABASE INFORMATION SPECIFIC TO INSTALLATION SITE ***
```
The values you need to provide are for the database URL, user, and password.

See the topic Building and Running the EJB Sample Applications for additional information about how to build and run the JDBC sequence bean sample application.

Javadoc

The javadoc for the JDBC bean sample is available at the following location:

Package samples.j2ee.ejb.sequence.jdbc