asp体系结构的发展外文翻译-jsp程序(编辑修改稿)

asp体系结构的发展外文翻译-jsp程序(编辑修改稿)内容摘要：

d of structure has solved traditional Client/Server can expand problem, have reduced customer end business logic , and have reduced the requirement of customer end for hardware. At the same time because of a lot of business logic concentrations have gone to unitary application server on, the maintenance work of application system had been also concentrated together, have eliminated the problem in the traditional structure of Client/Server that software distributes. This kind of structure is called as the architecture of B/S. Browser/Server and browser / server hold the architecture of B/S. On essence, Browser/Server is also a kind of structure of Client/Server, it is a kind of from the traditional two levels of structural development of Client/Server e to the threelayer structural special case of Client/Server that applied on Web. In the system of Browser/Server, user can pass through browser to a lot of servers that spread on work to send request. The structure of Browser/Server is maximum to have simplified the work of client puter, on client puter, need to install and deploy few customer end software only , server will bear more work, for database visit and apply program carry out will in server finish. Under the threelayer architecture of Browser/Server, express layer ( Presentatioon ) , function layer ( Business Logic ) , data layer ( Data Service ) have been cut the unit of 3 relative independences: It is the first layer of to express layer: Web browser. In expressing layer contain system show logic, locate in customer end. It39。 s task is to suggest by Web browser to the certain a Web server on work that service is asked , after verifying for user identity, Web server delivers needed homepage with HTTP agreement to customer end, client puter accept the homepage file that passed , and show it in Web browser on. Second layer function layer: Have the Web server of the application function of program extension. In function layer contain the systematic handling of general affairs logic, locate in Web server end. It39。 s task is the request concerning accepting user , need to be first conducted and corresponding to expand application program and database to carry out connection , passes through the waies such as SQL to database server to put forward data handling to apply for, then etc. database server the result of handling data submit to Web server, deliver again by Web server to return customer end. The number of plies of 3th according to layer: Database server. In data layer contain systematic data handling logic, locate in database server end. It39。 s task is to accept the request that Web server controls for database, realization is inquired and modified for database , update etc. function, submit operation result to Web server. Careful analysis is been easy to see , the architecture of Browser/Server of threelayer is the handling of general affairs of the two levels of structure of Client/Server logic modular from the task of client puter in split , from the first floor of individual position bear the pressure of its task and such client puter have alleviated greatly, distribute load balancedly and have given Web server, so from the structural change of Client/server of original two floor the structure of Browser/Server of threelayer. This kind of threelayer architecture following picture shows. This kind of structure not only client puter from heavy burden and the requirement of performance that rises continuously for it in liberation e out , also defend technology people from heavy maintenance upgrading work in free oneself. Since client puter handles general affairs , logic partial minutes have given function server, make client puter right off slender a lot of, do not take the responsibility for handling plex calculation and data again visit etc. crucial general affairs, is responsible to show part, so, maintenance people do not rush about again for the maintenance work of program between every client puter, and put major energy in the program on function server update work. Between this kind of threelayer structural layer and layer, the mutually independent change of any first floor does not affect the function of other layer. It has changed the defect of the two levels of architecture of Client/Server of tradition from foundation, it is the transform with deep once in application systematic architecture. The contrast of two architectures The architecture of Browser/Server and the architecture of Client/Server pare with all advantages that not only have the architecture of Client/Server and also have the architecture of Cli/Server the unique advantage that place does not have: Open standard: The standard adopted by Client/Server only in department unification for but, it39。 s application is often for special purpose. It is lower to develop and defend cost: It need to be implemented on all client puters that the application of Client/Server must develop the customer end software for special purpose, no matter installation and disposition escalate still, have wasted manpower and material resources maximumly. The application of Browser/Server need in customer end have general browser , defend and escalate to work in server end go on , need not carry out any change as customer holds , have reduced the cost of development and maintenance so greatly. It is simple to use , interface friendly: The interface of the user of Client/Server is decided by customer end software, interface and the method of its use are not identical each, per popularize a system of Client/Server ask user study from the beginning, is hard to use. The interface of the user of Browser/Server is unified on browser, browser is easy to use , interface friendly, must not study use again other software, the use of a Lao Yong Yi that has sol。