Design And Application Of J2EE Persistence Layer Framework Of DR-ORM

The structure of traditional application web framework was divided into three tiers. They are presentation tier, business logic tie, and infrastructure tier. Business logic tier has two responsibilities at the three tiers structure:business logic and data access. Business logic tier get the data which business logic needed according basic database operation. But it takes a Problem that basic logic and database access in integrate compactness. For separating the detail of data access tie from business logic, we can independence the data access tie, so it becomes J2EE five tiers structure.Persistence tier is an important element of J2EE framework. The function of persistence tier is store the data of business state, it accomplish the transfer of application by communicate with other systems. Object-Oriented method nowadays is a main technology in computer software development. In the process of software development by00, relational database is most popular. But it must face a problem that the description of data not consistent when the system base on object model store data from relational database. ORM (object relation mapping) is an effective solution techniques.Based on reading the domestic and overseas literatures, this paper summarizes the research background and significance of the ORM, the domestic and overseas research development, the relative technologies and concepts and so on. By the analysis and comparison of each kind of techniques, characteristic, the research thinking and the technology and method of the realization are put forward. On the basis of dissertating. The theory and implement method of object relation mapping, a J2EE persistence tier framework base on ORM which called DR-ORM, is presented. This paper describes the design methods and design patterns of the DR-ORM, using the DAO design pattern, this framework has the function and mechanisms of object relation mapping, so that software engineer can progress data access in manner of object oriented, and pay no attention at the implement of bottom database, it can greatly improve the efficiency of program development. Finally, the paper implements a BBS system based on DR-ORM framework, and then verifies its feasibility.