Operating Systems: i5/OS
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Assembling data access applications
When you assemble enterprise bean code into files that can be deployed
onto an application server, you configure properties that define how the application
accesses an enterprise information system (EIS), such as a database.
This topic assumes that you have created an enterprise application containing an EJB module that
must transact with a database.
Overview
A data access application uses resources, such as data sources or
connection factories, to connect with a database.
An application component
uses a connection factory to access a connection instance, which the
component then uses to connect to the underlying enterprise information system
(EIS). Examples of connections include database connections, Java Message
Service connections, and SAP R/3 connections.
During application assembly
you perform activities that enable the application to use these resources.
The process typically requires an assembly
tool.
Procedure
- Identify the logical names that are used by the EJB module to reference
application resources. These logical names are called resource references.
For further explanation, consult The benefits of using resource references topic.
- Start an assembly tool.
- If you have not done so already, configure the
assembly tool for work on J2EE modules. Ensure that J2EE capability
is enabled.
- Define mapping and
security properties for the resource references. This process
includes the following activities:
- Bind the resource references to the application resources that
provide database connectivity.
See the Data source lookups for enterprise beans and Web modules topic for more information on the concept of binding.
At deployment time you can alter your bindings if necessary.
- For each resource define an authentication type, which is the
security configuration through which database connections are granted.
There are two authentication types:
- Component-managed
-
The enterprise bean code performs EIS signon for data source or connection
factory connections.
- Container-managed
-
WebSphere Application Server performs EIS signon.
Consult the J2EE connector security topic
for detailed reference on resource authentication.
- Configure access intent assembly
settings for your enterprise beans.
- Right-click your EJB module in a Project Explorer view and click Open
With > Deployment Descriptor Editor.
- In an EJB Deployment Descriptor editor, select the Access tab.
- Under Isolation Level, click Add.
- Select the isolation level, enterprise beans, and method elements.
For information on isolation levels, press F1.
- Click Finish.
- Map enterprise beans to database tables. For an
overview of the mapping options in the Application Server Toolkit, consult Approaches for mapping enterprise beans to database tables.
Results
Files for the updated application are shown in the Project Explorer
view.
What to do next
After testing your application, you are ready to deploy your application to an application server.
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Creating or changing a resource reference
Assembling resource adapter (connector) modules
Migrating applications to use data sources of the current J2EE Connector
Architecture (JCA)
Related concepts
JDBC providers
Data sources
Related Reference
Data access: Resources for learning
Related information
Starting the Application Server
Toolkit assembly tool
Configuring the Application Server
Toolkit assembly tool
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