Deploy data access applications

 

Frequently, deploying data access applications involves more than installing your WAR or EAR file onto a server. Deployment can include tasks for configuring your application to use the data access resources of the server and overall run-time environment. You can only deploy application code that is assembled into the appropriate modules. The topic Assembling data access applications provides guidelines for this process.

 

Overview

Perform the following steps if your application requires access to a relational database (RDB). If your application requires access to a different type of enterprise information system (EIS), such as an object-oriented database or the Customer Information Control System (CICS), consult the topics Resource adapters and Accessing data using J2EE Connector Architecture connectors.

 

Procedure

1. If your RDB configuration does not already exist:

   1. Create a database to hold the data.

   2. Create tables required by your application.

      If your application uses CMP entity beans to access the data

      You can create the tables using the data definition language (DDL) generated from the enterprise bean configuration. For more information, see Recreating database tables from the exported table data definition language.

      If your application uses BMP entity beans, or does not use entity beans

      You must use your database server interfaces to create the tables.

      You can also use the EJB to RDB Mapping wizard of an assembly tool to create your database tables for either type of entity bean. Select the top-down mapping option in the wizard. Keep in mind, however, that this option does not give you direct control in naming the RDB elements or choosing column types. Additionally, because the top-down process is automatic, it might not provide mappings to reflect the precise relationships that you intend.

      If you use the Application Server Toolkit (AST), consult the that product information center about the mapping wizard. To learn about all of your assembly tool options, consult the Assembly tools article in this information center.

   3. Check Data source minimum required settings, by vendor to see any database vendor requirements for connecting to an appserver.

2. If necessary, map your entity beans to the database tables through the meet-in-the-middle mapping option of an assembly tool. This step is necessary only if you did not create your database schema through the top-down mapping option, did not generate your mapping relationships through bottom-up mapping, or did not generate mappings during the application assembly process. For information on the top-down mapping option refer to the Application Server Toolkit information center.

3. Install your application onto the appserver. Consult Installing J2EE application files. When you install the application, you can alter data access settings that were made during application assembly, or set them for the first time if they were omitted from the assembly process. These settings include resource bindings and resource authentication aliases, which are addressed in the following substeps:

   1. Bind application resource references to the data sources, or other resource objects, that provide database connectivity. For details on the concept of binding, see the Data source lookups for enterprise beans and Web modules topic.

      After deployment, you can use the WAS console to alter resource bindings. Click Applications > Enterprise Applications > application, and select the link to the appropriate mapping page. For example, if you want to alter the binding of an EJB module resource, you might click 1.x CMP bean data sources or 2.x CMP bean data sources. For a Web module resource, click Resource references.

   2. Define authentication alias data for resources that must be authenticated with the backend through container-managed authorization. In this security configuration, WAS performs EIS signon for data source or connection factory connections. Consult the J2EE connector security topic for detailed reference on resource authentication.

4. Start the deployed application files using the console , the wsadmin startApplication command, or your own Java program.

5. Save the changes to your administrative configuration.

6. Test the application. For example, point a Web browser at the URL for a deployed application and examine the performance of the application.

 

Results

When you deploy an application that uses a DB2 UDB for i5/OS back-end database, you might find the following exception in the SystemOut.log file:

PMGR6022E: Error using adapter to create or execute an Interaction

This type of error indicates that you deployed an application with Container-managed persistence (CMP) enterprise beans that were originally configured to access a DB2 database on Windows, Linux, or a supported UNIX system. Using the administrative console, uninstall the affected CMP applications, then reinstall the applications with the new database setting. Remember to select Deploy enterprise beans; on the EJB deploy panel, select the appropriate version of your DB2 UDB for i5/OS database.

 

What to do next

If the application does not perform as desired, update the application, then save and test it again.

---

Available resources

1.x CMP bean data sources

1.x entity bean data sources

2.x CMP bean data sources

2.x entity bean data sources

 

Related concepts

Data sources
Data source lookups for enterprise beans and Web modules
Resource adapters
The benefits of using resource references

 

Related tasks

Creating or changing a resource reference
Installing J2EE application files
Assembling applications
Administering data access applications

 

Related Reference

Data source minimum required settings, by vendor
Resource references

 

Related information

Overview of Application Server Toolkit