The Application Of J2EE/EJB Technology In E-Government System

Taking into account the progress of E-government system, Distributed component technology is the appropriate way to resolve most of difficulty in operation of E-government system. Distributed component technology is usually used to operate those distributed application systems whose aims are sharing resource and cooperating with each other. Therefore, they are usually developed,deployed,managed and vindicated on the network platform. Currently, three models of the distributed component technology are used widely: COM/DCOM , CORBA and J2EE/EJB。J2EE/EJB which Sun Microsystems proposed provided a well-structure frame for distributed application development. Using EJB(Enterprise Java Beans), developer can focus on the define and development of business logic, without concern on the detail of distributed application, which can improve the productivity of application and performance of systems, such as reusability, stability and expandability. In the development of E-government system, J2EE/EJB have the unparalleled superiority.As a model of developing and deploying reusable Java server-side components, EJB defines a standard programming interface for Java application servers. Java language is independent of developing platform. With the specialty of EJB model, the EJB component has excellence of "once write, use everywhere". And EJB component means "position clarity " to users, who do not need to concern on the detail of EJB component. In the whole solvent of distributed application which Sun Microsystems provides, EJB plays an import role. This thesis mainly describes the specifications,the working principle and applications in the multi-tier architecture of EJB. The components and the techniques concerned are expounded as well. EJB is composed of Enterprise Java Beans, Home interface, Remote interface and some XML files which describes how to deploy EJB. The thesis gives the common developing flow of Enterprise Java Beans, provides the functions of all interface. Some knowledge of XML files are described, too. And the measure about how to optimize the performance of EJB are discussed in the thesis. At last, as a example of developing EJB component, the E-tax system of JianShi county, HuBei province is introduced.