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Configuring WebLogic J2EE-CA
Configuring and deploying a resource adapter in WebLogic is a straightforward process. The end result is a special Java archive file called a resource adapter archive (*.rar), or RAR file for short. Each RAR file has all the classes needed for the resource adapter plus the configuration XML files ra.xml and the WebLogic-specific weblogic-ra.xml.
Resource Adapter Developer Tools
BEA makes several tools available for configuration and deployment of the J2EE-CA. Minimally, you need at least a text editor to modify or create the ra.xml and weblogic-ra.xml files. Although when you actually deploy the RAR file within WebLogic 8.1, it creates a weblogic-ra.xml file and puts that file in the RAR automatically. If you deploy the resource adapter expanded—meaning not in a RAR file but just a simple directory structure—you can edit the weblogic-ra.xml file from the console. After editing, simply click Apply at the bottom right of the screen, and the changes are updated and the resource adapter is redeployed.
When creating or modifying the ra.xml file, an XML editing tool is beneficial. WebLogic provides a XML editor: WebLogic Builder, which is included with WebLogic 8.1.
Configuring Resource Adapters
Resource adapters are meant to be configured and optimized for your intended application. Earlier in the chapter, the ra.xml and weblogic-ra.xml files were discussed. These two files hold the entire configuration for the resource adapter. When editing the configuration files, a few conventions must be followed. First, each tag has a corresponding end tag. Second, case should be followed not only in the name of the tag itself, but also in its value if needed. Finally, to use the default value of an optional element, omit the tags altogether or specify an empty value within the tags.
The file mandated to hold all the J2EE Adapter Architecture–specified configuration is called ra.xml. The DTD can be found at http://java.sun.com/dtd/connector_1_0.dtd.
The main element in a ra.xml file is the <connector></connector> element. All other elements are contained within these tags. For the connector to validate against the DTD, it must contain these five elements:
Optionally, four other tags can be specified within the connector tags: display-name, description, icon, and license. The display-name and description tags are text tags that are for display in resource adapter tools. The icon tag specifies icons that can be displayed with the resource adapter. The license tag tells the user whether a license is required to be distributed with the resource adapter.
The resourceadapter Tag
The resourceadapter tag and associated subtags are most important in the configuration of the resource adapter. This tag specifies what classes the resource adapter uses for each of the required interfaces in the J2EE Connector Architecture specification, plus other required parameters. The following list describes the required tags:
Optional tags that are included in the specification are as follows:
To learn more about the intricacies of the ra.xml file, information is available from Sun as part of the J2EE-CA specification located at http://java.sun.com/j2ee/connector/download.html.
The J2EE Connector Architecture forbids any extra configuration within the ra.xml file. To allow application server vendors the opportunity to fine-tune resource adapters, connector vendors must use an external configuration medium that can contain application server–specific information. WebLogic puts this information in the weblogic-ra.xml file. If the weblogic-ra.xml file does not exist, it is automatically generated when the resource adapter is deployed. The DTD can be found at http://www.bea.com/servers/wls810/dtd/weblogic810-ra.dtd.
The weblogic-ra.xml file has a root node labeled <weblogic-connection-factory-dd> and several configuration parameters, but only two that are required. The two required parameters are as follows:
The optional parameters should be configured to optimize the needs of the intended application. The following is a list and a brief description of each parameter:
The following excerpt from a weblogic-ra.xml file shows some of the optional configuration properties in use. These properties enable logging, specify the name logging file, and map a property from the ra.xml file to a new value based on the <config-property-value> in the weblogic-ra.xml file.
<weblogic-connection-factory-dd> <connection-factory-name>eis/jcaconn</connection-factory-name> <jndi-name>eis/jcaconn</jndi-name> <logging-enabled>true</logging-enabled> <log-filename>jcaoutput.log</log-filename> <map-config-property> <config-property-name>ConnectionURL</config-property-name> <config-property-value>jdbc:pointbase://localhost/demo</config-property-value> </map-config-property> </weblogic-connection-factory-dd>
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