基于MVC模式电子商务网站(BC)分析与设计.docx

Before we start our journey into the internals of Spring MVC, we first need to understand the
different layers of a wessage would work with Holla.
Figure 1-1. Sending a new chat message from Holla 1. The user submits a new chat message.
2. The controller ’ s event handlers. trigg
The controller creates a new Chat Model record.
The controller then updates the view.
The user sees his new chat message in chat log.
The MVC architectural pattern can even be implemented without libraries or frameworks. The key is to divide up the responsibilities of the MVC components into clearly defined sections of code, keeping them decoupled. This allows for independent
development,testing, and maintenance of each component.
Let ’ s explore the components of MVC in detail.
The Model ：
The mo del is where all the application ’ s data objects are stored. For example, we might have
a User Model that contains a list of users, their attributes, and any logic associated specifically
with that model.
A model does not know anything about views or controllers. The only thing a model should contain is data and the logic associated directly with that data. Any event handling code, view templates, or logic not specific to that model should be kept well clear of it. You know an application ’ s MVC architectureisviolated when you start seeing view