OSGi/WebBeans configuration
Since OSGi bundles mainly provide services, for example authentication or JMS, you’ll need to configure the service to point to the user database or JMS queue destinations. Naturally, I’d recommend using WebBeans as the configuration format because it’s a Java standard, compact, and powerful. The official spec JSR-299 is on the JCP website.
Configuring a service generally involves creating a Java instance of the service class, configuring any properties, and registering the service with the OSGi and WebBeans, so it’s available to any application that needs the service.
To specify the class, the latest WebBeans draft uses a combination of an XML namespace and the XML element name, letting you instantiate any Java object an a minimum of verbiage. So the namespace xmlns:r=”urn:java:com.caucho.server.security” and the XML name r:XmlAuthenticator, would create an instance of Resin’s XML authenticator “com.caucho.server.security.XmlAuthenticator”.
<r:XmlAuthenticator xmlns:r="urn:java:com.caucho.server.security"> <r:password-digest>none</r:password-digest> <r:user name="harry" password="quidditch"/> </r:XmlAuthenticator>
The best part about the syntax is the removal of all overhead tags, so the configuration concentrates on the object itself. The only extra tag is the “xmlns:r” to specify the namespace. Otherwise, all the names are critical to the class and its properties. In other words, the new WebBeans syntax avoids annoying tokens like: <bean>, “class”, <property>, <name>, <value>, etc. It’s clean and simple.