Programming Jakarta Struts

Struts Model Components

There are several different ways to look at what constitutes a model for Struts. The lines between business and presentation objects can get quite blurry when dealing with web applications—one application’s business objects are another’s data transfer objects (DTOs).

It’s important to keep the business objects separate from the presentation so that the application is not tightly coupled to one type of presentation. It’s likely that the look and feel of a web site will change over time. Studies show that the freshness of a web site’s appearance helps to attract new customers and keep existing customers coming back. This may not be as true in the business-to-business (B2B) world, but it’s definitely true for business-to-consumer (B2C) applications, which make up the majority of the web applications used today.

Using Data Transfer Objects

DTOs (also referred to as value objects) often are used to provide a coarse-grained view of remote, fine-grained data. If your application were using entity beans, for example, instead of making several remote calls to get individual state about the object, you could make a single call that would return a local DTO containing all the data you need. Sometimes there is a summary and a detailed version for the remote object to mitigate how much data is returned.

Although the DTO represents the remote business object, it doesn’t necessarily contain the same business logic. In fact, it generally doesn’t contain any business logic ...