This page talks about how to use the database pool ${pool.name} from a J2EE application. The example here is a web application, but other application modules would work in the same way.
WEB-INF/web.xml
The web.xml should have a resource-ref section declaring the database pool, like this. Note the res-ref-name, which is what we'll need to map the reference to a pool, and also what the application will need in order to access the pool.
<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
version="2.4">
<!-- servlets and mappings and normal web.xml stuff here -->
<resource-ref>
<res-ref-name>jdbc/MyDataSource</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
</web-app>
WEB-INF/geronimo-web.xml
To point the resource reference to a specific database pool in Gernimo, the web application needs to have a geronimo-web.xml deployment plan. That may be packaged in the WAR in the WEB-INF directory, or it may be provided separately on the command line to the deploy tool. The geronimo-web.xml plan should have a resource-ref block corresponding to the one above, which maps the resource reference to a specific database pool. In that block, the ref-name must match the res-ref-name from the web.xml (above) and the resource-link must point to the database pool.
If you have only one pool named ${pool.name} deployed in Geronimo, you can point to it like this.
<?xml version="1.0" encoding="UTF-8"?>
<web-app
xmlns="http://geronimo.apache.org/xml/ns/j2ee/web-1.0"
xmlns:naming="http://geronimo.apache.org/xml/ns/naming-1.0"
configId="MyConfigName">
<context-root>/MyWebApp</context-root>
<context-priority-classloader>true</context-priority-classloader>
<!-- security settings, if any, go here -->
<naming:resource-ref>
<naming:ref-name>jdbc/MyDataSource</naming:ref-name>
<naming:resource-link>${pool.name}</naming:resource-link>
</naming:resource-ref>
</web-app>
That will search for a pool named ${pool.name} in both the current application and as a server-wide pool.
If you have more than one pool named ${pool.name} (for example, one as a server-wide pool and one deployed within an application EAR), then you can specify the pool to use more explicitly like this:
<?xml version="1.0" encoding="UTF-8"?>
<web-app
xmlns="http://geronimo.apache.org/xml/ns/j2ee/web-1.0"
xmlns:naming="http://geronimo.apache.org/xml/ns/naming-1.0"
configId="MyConfigName">
<context-root>/MyWebApp</context-root>
<context-priority-classloader>true</context-priority-classloader>
<!-- security settings, if any, go here -->
<naming:resource-ref>
<naming:ref-name>jdbc/MyDataSource</naming:ref-name>
<naming:domain>${pool.objectNameMap['domain']}</naming:domain>
<naming:server>${pool.objectNameMap['J2EEServer']}</naming:server>
<naming:application>${pool.objectNameMap['J2EEApplication']}</naming:application>
<naming:module>${pool.objectNameMap['JCAResource']}</naming:module>
<naming:type>${pool.objectNameMap['j2eeType']}</naming:type>
<naming:name>${pool.objectNameMap['name']}</naming:name>
</naming:resource-ref>
</web-app>
Application Code
To get a reference to the database pool, your application can use code like this. Note that the JNDI lookup string is java:comp/env/ plus the res-ref-name used in web.xml (above).
protected void doGet(HttpServletRequest request, HttpServletResponse response) {
try {
InitialContext ctx = new InitialContext();
DataSource ds = ctx.lookup("java:comp/env/jdbc/MyDataSource");
Connection con = ds.getConnection();
} catch(NamingException e) {
...
} catch(SQLException e) {
...
}
}