This paper provides an overview of using Enterprise JavaBeans to build an e-business system. First, the authors point out some difficulties during building an e-business sy stem. For example, how can we integrate all ...This paper provides an overview of using Enterprise JavaBeans to build an e-business system. First, the authors point out some difficulties during building an e-business sy stem. For example, how can we integrate all kinds of software and hardware i n company quickly and economically Then the authors introduce a representative EJB structure and currently EJB deve loping approaches. A representative EJB structure includes an EJB Server, EJB Co ntainers, EJB Clients and JNDI etc. An EJB Server is similar to CORBA ORB. It pr ovides system services such as original implementing environment, multiprocessin g, workload management, equipment accessing, JTS and JNDI service and making the EJB Container visible. The EJB Container plays the role of interface between th e EJB and others. An EJB Client never accesses Bean directly. There are two kind s of containers. One is session contain, it mainly includes brief, impermanent E JB(thus all statuses will not be saved). The other is entity container which inc luding permanent EJB. The EJB Client uses EJB Beans. First it finds EJB Containe r through JNDI interface. Then it transfers EJB methods using EJB Container. Current, EJB developing approaches include several major aspects such as develop ment, deployment, application programs assembling and management of Enterprise B ean etc. Above all, we should define three classes, Bean class, home interface c lass of Bean and remote interface class of Bean. Then we should create a deploym ent descriptor. This is an XML documentation, which declared the properties of E nterprise Bean and bound the class documentations of Bean(including stub documen tation and skeleton documentation). And then we put these deployments into a jar documentation and define environment properties in the deployer. Next, we shoul d assemble application programs including install Enterprise Beans to server and test the connecting of each ties. The program assembler integrates several Ente rprise Beans with other beans(like Servlet, Applet, Script etc) into an integrat ed application program. It also may integrate several Enterprise Beans into a co mplicated Enterprise Bean. Of cause we also need to manage the Enterprise Bean. In the end, the authors point out several major advantages of using EJB to build e-business system such as simplifying application development and deployment, supporting heterogeneous client and server platforms, leveraging existing skills and assets, delivering a secure, scalable, reliable and manageable environment and providing the freedom to implement using many vendors’ products.展开更多
文摘This paper provides an overview of using Enterprise JavaBeans to build an e-business system. First, the authors point out some difficulties during building an e-business sy stem. For example, how can we integrate all kinds of software and hardware i n company quickly and economically Then the authors introduce a representative EJB structure and currently EJB deve loping approaches. A representative EJB structure includes an EJB Server, EJB Co ntainers, EJB Clients and JNDI etc. An EJB Server is similar to CORBA ORB. It pr ovides system services such as original implementing environment, multiprocessin g, workload management, equipment accessing, JTS and JNDI service and making the EJB Container visible. The EJB Container plays the role of interface between th e EJB and others. An EJB Client never accesses Bean directly. There are two kind s of containers. One is session contain, it mainly includes brief, impermanent E JB(thus all statuses will not be saved). The other is entity container which inc luding permanent EJB. The EJB Client uses EJB Beans. First it finds EJB Containe r through JNDI interface. Then it transfers EJB methods using EJB Container. Current, EJB developing approaches include several major aspects such as develop ment, deployment, application programs assembling and management of Enterprise B ean etc. Above all, we should define three classes, Bean class, home interface c lass of Bean and remote interface class of Bean. Then we should create a deploym ent descriptor. This is an XML documentation, which declared the properties of E nterprise Bean and bound the class documentations of Bean(including stub documen tation and skeleton documentation). And then we put these deployments into a jar documentation and define environment properties in the deployer. Next, we shoul d assemble application programs including install Enterprise Beans to server and test the connecting of each ties. The program assembler integrates several Ente rprise Beans with other beans(like Servlet, Applet, Script etc) into an integrat ed application program. It also may integrate several Enterprise Beans into a co mplicated Enterprise Bean. Of cause we also need to manage the Enterprise Bean. In the end, the authors point out several major advantages of using EJB to build e-business system such as simplifying application development and deployment, supporting heterogeneous client and server platforms, leveraging existing skills and assets, delivering a secure, scalable, reliable and manageable environment and providing the freedom to implement using many vendors’ products.
