Create or changing a resource reference

A resource reference supports application provider access to a resource (such as a data source, URL, or mail provider) using a logical name rather than the actual name in the run time environment. This ability insulates the application provider from the run time configuration, and simplifies the process of changing the run time configuration.

 

Before you begin

This article assumes that you have created an enterprise application whose resource references you want to update.

 

Overview

Resource references are declared in the deployment descriptor by the application provider. At some point in the application deployment process, bind the resource reference to the actual name of the resource in the run time environment.

This article describes how to update the resource references of an enterprise application using an assembly tool such the Application Server Toolkit (AST) or Rational Web Developer.

 

Procedure

1. Start an assembly tool.

2. If you have not done so already, configure the assembly tool for work on J2EE modules.

3. Import the enterprise application (EAR file) you want to change.

4. Display the resource references for the type of module:

   • If an enterprise bean uses the resource reference:

     1. Expand the name of the EAR file.

     2. Expand EJB Modules.

     3. Expand the EJB module wanted.

     4. Expand the section for the appropriate type of enterprise bean (Session Beans or Entity Beans).

     5. Expand the enterprise bean.

   • If a servlet uses the resource reference:

     1. Expand the name of the EAR file.

     2. Expand Web Modules.

     3. Expand the Web module wanted.

   • If an application client uses the resource reference:

     1. Expand the name of the EAR file.

     2. Expand Application Clients.

     3. Expand the application client module wanted.

5. Right-click the module whose resource references you want to change and click Open With > Deployment Descriptor Editor.

6. For servlets and application clients, click Add. For EJB modules, select the particular bean and click Add.

7. Select the resource reference option and click Next.

8. Specify the settings and click Finish.

9. Optional: Select the References tab and, under WebSphere Extensions, select an isolation level. If you choose to forego this step, the isolation level defaults to TRANSACTION_NONE.

10. Optional: Under WebSphere Bindings, specify a JNDI name. If you choose to forego this step one can set (or override) the binding when the application is deployed.

11. Close the deployment descriptor editor and save your changes.

 

Result

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

 

What to do next

Verify the contents of the updated enterprise application in the Project Explorer view. Then, deploy your enterprise application.

We can generate EJB deployment code and deploy an EJB module to a target server in one step. In the Project Explorer view, right-click on the EJB project and click Deploy.

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See Also

Data sources
Binding to a data source

 

See Also

Data access : Resources for learning

 

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