Object oriented programming is the main stream nowadays on software project development while relational database are also widely used. How to deal with the problem of Object and Relation mapping is a complex question in this area and it is a hard and difficult problems on enterprise development process. It is suitable to finding solutions about ORM in the application level instead of changing the relational database which widely used today.Deal with the problem of object and relation mapping is to solving the problem of data persistence. In J2EE, it brings forward the frame of data persistence layer aim at this question. The frame of data persistence layer build upon data source contains a series of software services which separate data source from applications, and provide data access API to developer. The developer could develop applications base on the data persistence layer.The paper concentrate on the study of design and realization of the core function in the data persistence layer . the author deep makes deep research on the infrastructure of J2EE , study the common idea of design about the data persistence layer, compare the strongpoint and shortcoming among a series of solutions, bring forward some models and methods to create a data persistence layer combine with the functions and solutions of Hibernate and other applications. To improve the efficiency and veracity of development, the paper also discusses the assistant tools of data persistence layer. At last, validate the usability and reliability of the data persistence layer base on a concrete system.Plenty of theoretic research proves that take the data persistence layer into the software system can bring many advantages, it can improve the efficiency of the programmed, reduce the appearance of error, improve the system's usability and reuse, reduce the cost of system'maintenance , improve the company's productivity and quality of service. |