Head First Servlets and JSP, 2nd Edition

The “go-between” is a Business Delegate

Let’s take a look at the pseudo-code for a typical Business Delegate, and at how Business Delegates tend to be deployed in the web container.

Notice that there will be LOTS of Business Delegates on the web tier.

A Business Delegate’s pseudo-code

// get the request and do a JNDI lookup
// get back a stub

// call to the business method
// handle & abstract any remote exceptions
// send the return value to the controller

Sharpen your pencil

Uh-oh. Duplicate Code Alert.

(Describe where the duplicate code exists and how you could solve that problem.)