Research And Implementation Of The J2EE Architecture Integrated With Struts And JDO

In recent year, with the rapid development of network and extensive adoption of J2EE platform, multi-layer Web structure based on B/S grows up gradually. MVC design pattern separates control of data from representation of data, and therefore has the advantage of implementation of multi-layer Web applications. Struts is the application framework that implements MVC based on J2EE platform. It eases the burden of constructing multi-layer Web applications and provides reusable software architecture. In Struts, object persistence generally is implemented through JDBC and EJB. JDBC can access easily several kinds of databases synchronously by SQL language and build a base of operating each other among them. It provides a good mechanism that makes the application is independent of vendors and location of the database. But JDBC has also many deficiencies. For example, we can only use a compatible database with it, programming of database is complex and dull and easily makes mistakes, we need master SQL language but SQL language of each kind of database is incompletely compatible. On the other hand, although EJB supports transparent persistence, make application transplantable and provides flexible transaction management, it makes program more complex, wastes more time to be built and response, it also needs vast system recourses.As is stated above, firstly this thesis did research in JDO that is a new lightweight persistence criterion. It introduced the formative history of JDO and its architecture, analyzed its kinds of lifecycle states and main lifecycle transitions, explained what is JDO identity, represented how to name the persistence descriptor and its elements, expound the process of implementing object persistence through JDO and current status of JDO. This thesis also compared JDO to other persistence technology and summarized its advantage.Then the thesis analyzed the localization in implementing object persistence of the J2EE architecture based on Struts and divided the object persistence tier from it. And then integrated JDO, a lightweight object oriented persistence technology, into the architecture and built a better architecture which meet the characteristic of N-tiesweb architecture.This thesis emphatically analyzed the theory and key technology of the architecture and introduced its characteristic. The architecture took the advantage of JDO well and made developed application with it hold much benefit. For example, it has good design theory and is easy to implement the development and management of a large-scale application system, make the system business reusable and revisable, save cost and time, hold better system performance and transplantable characteristic, and so on. Finally, a typical Web application-online drugstore-is designed and implemented using this architecture.