When Java people introduced JSP and Servlet technology, they also provided a development road map for working with JSP and Servlet and defined two architecture models for developing JSP or Servlet based web applications. The two models are known as Model 1 and Model 2 and they prescribe different approaches to designing JSP or Servlet based Web applications. Model 1, the simpler of the two, was the primary solution implemented when JSPs were first introduced. However, over time, Model 2 has been accepted as the best way for building JSP or Servlet based Web applications.
JSP model 1 architecture overview
In JSP model 1 architecture, a request is made to a JSP or servlet and then that JSP or servlet handles all responsibilities for the request, including processing the request, validating data, handling the business logic, and generating a response. The model 1 architecture is commonly used in smaller, simple task applications due to its ease of development.
This architecture is not fitting best to large-scale application development because, inevitably, a great deal of functionality is duplicated in each JSP or Servlet. Also, the Model 1 architecture unnecessarily ties together the business logic and presentation logic of the application. Combining business logic with presentation logic makes it hard to introduce a new ‘view’ or access point in an application.