The front end time participated in an e-commerce project, and the system architecture is out of life. Here is the Web layer, the business layer, and the persistent layer, sharing with you.
The web layer is: velocity turbine.velocity is a language equivalent to JSP. Compared with JSP, it makes it better to display the display function (actually because the Velocity language has no JSP powerful). There is no complex logic in Velocity, mainly responsible for displaying objects in VO. The shortcomings of the JSP with Struts correspond to the system, using Turbine as the control layer, connects the display layer and the business layer. The control layer is responsible for simple verification and calls Delegate. DELEGATE Call Session Bean.
The business layer is mainly encapsulated in AO (Application Object). The AO implementation business logic is only called in the session bean. Returning CONTEXT from AO until the control layer. The reason why it does not call AO directly from the control layer is for future expansion, and layered, deployment.
The database persistence is used for iBATIS. Some people in the development process are responsible for Dao, and we can tell him if we need to tell him. Ibatis is an open source framework. Unlike Hibernate is that it is not mapping of JavaBean and database tables, but a mapping of JavaBean and SQL statements. And all database operations can be configured in the XML file without hard coding into the Java program.
One of the framework is that the database returns to DO (Database Object), and the page is Vo (Value Object). Multiple DO objects can be merged into a VO object, corresponding to a page.
A lot of services are used in the framework, and the service is configured through the XML file.
