I finally browsed the book I bought before, it is worth celebrating. The J2EE Pattern is divided into a layer, a business layer, and an integrated layer. These patterns are: [Representation layer mode] -Intercepting filter-front controller-view helper-composite view-service to worker-dispatcher view [business layer mode] -Business Delegate-Value Object-Value Object Assembler-Value List Handler-Service Locator [Integrated layer mode] -Data Access Object-Service Activator is in the representation layer mode, the specification of Servlet, JSP And the framework is implemented, like the filter, Filter in the servlet can inherit the use; like the front-end controller, the ActionServlet is implemented in Struts; like a view assistant, it has been used in early development, JavaBean or tag Library, etc .; as the worker service and distributor view is a combination of several previous modes. So I think that in the representation, as long as you use the existing framework, you will naturally follow the conventions of these modes of the layer. In the mode of the business layer and the integrated layer mode, like Vo, DAO, etc., should be commonly used. Other modes of the business layer are closely related to EJB. In short, contact these 15 J2EE patterns, giving me the deepest impression is the "layering" concept, and separate the questions first, and then divide the "Professional" small class in each layer. Try to make a class complete the special and simple (conceptually simple) functionality. Another impression is to pay attention to performance and security in distributed system development, to give an example, set the front-end controller to satisfy the needs of security; like composite entities, VO mode, intended to mitigate the network Data traffic, the degree of response, etc. In a word: decoupling, decoupling, and decoupled! Some nonsense: I feel that the "amount" to do is unchanged regardless of how the methods and technology develop. Just like a layered, you are a hierarchical, but when you commission it, don't spend time? Change one person to take over, he needs a layer of finding, don't spend time? You said your program is good maintenance, you don't need to know more knowledge, spend time to analyze the design? Remembering the sentence of Jinmao Wang in the Shaolin Temple and Shangqima: Niu Ming Xunxiao.
