Assembling data access applications

When you assemble enterprise bean code into files that can be deployed onto an appserver, you configure properties that define how the application accesses an enterprise information system (EIS), such as a database.

This page assumes that we have created an enterprise application containing an EJB module that must transact with a database.

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.

 

1. 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, read the topic, The benefits of using resource references.

2. Start an assembly tool.

3. If we have not done so already, configure the assembly tool for work on Java EE modules.

   Ensure that Java EE capability is enabled.

4. Define mapping and security properties for the resource references.

   This process includes the following activities:

   1. Bind the resource references to the application resources that provide database connectivity.

      See the topic, Data source lookups for enterprise beans and Web modules, for more information on the concept of binding. At deployment time we can alter the bindings if necessary.

   2. 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

      WAS ND v7.0 performs EIS signon.

      See the topic, J2EE connector security, for detailed reference on resource authentication.

5. Set access intent policy settings for the enterprise beans.

   1. Right-click the EJB module in a Project Explorer view and click Open With > Deployment Descriptor Editor.

   2. In an EJB Deployment Descriptor editor, select the Access tab.

   3. Under Isolation Level, click Add.

   4. Select the isolation level, enterprise beans, and method elements. For information on isolation levels, press F1.

   5. Click Finish.

6. Map enterprise beans to database tables.

 

Results

Files for the updated application are shown in the Project Explorer view.

 

Next steps

After testing the application, we are ready to deploy the application to an appserver.

Set a resource reference
Assembling resource adapter (connector) modules
Migrate applications to use data sources of the current Java EE Connector Architecture (JCA)

 

Related concepts

JDBC providers
Data sources
Assembly tools
The benefits of using resource references
Data source lookups for enterprise beans and Web modules
J2EE connector security
Access intent policies

 

Related tasks

Install enterprise application files
Assembling EJB modules
Deploy EJB modules
Set a resource reference

 

Related

Data access: Links
Develop applications that use JNDI
Direct and indirect JNDI lookup methods for data sources
Connection factory JNDI name practices