## WebLogic Enterprise JavaBeans

"You've asked to be paged if any of your Gold service customers report a problem," the Java engineer said to Mr. Imayess, who nodded. "Global-Web has Gold service," he said, pointing to the Customer panel where the company name Global-Web was displayed.

"Let's add a new customer issue for Global-Web to test the automatic paging service. It's all event-driven, so it's fast." he said to Mr. Imayess. The Java engineer showed Mr. Imayess how to add a new customer service issue and set its status and level in the BigTel App.

Mr. Imayess' beeper went off. "Hey, nice!" Mr. Imayess smiled. "How did you do that?"

"We use an Enterprise JavaBean. It's a transactional component that makes it easy to do complicated things like dialing up the beeper company and making sure you get the page. The beeper has an EJB interface that allows client applications to send messages to the beeper within the context of an EJB transaction. When a message is sent, the session bean looks up the beeper in WebLogic Server's JNDI tree -- where the beeper has registered itself under a given phone number -- and activates the beeper over WebLogic RMI. Inside WebLogic Server there is a pool of stateless session beans -- think of them as operators on a switchboard -- that can send messages to one of many beepers. That is, the bean isn't tied to a particular beeper, but can send messages to any beeper that it can find in WebLogic Server's JNDI tree," said the Java engineer."

"Wow! So that means you might reuse that component for some other beeper-related task in another program?" asked Mr. Imayess.

"Yeah, exactly!" the Java engineer responded. "Components are a really powerful way to get the most bang out of your programming buck!"

"What about maintenance of this thing?" Mr. Imayess asked. "Isn't it going to be a nightmare?"

"Could be," the Java engineer said, "except that WebLogic Server has a great graphical management console. They even provide a public API so you can manage your own programs with the Console. Let's take a look at it."

More . . .