【正文】 ver 應(yīng)用都可以進行同樣的業(yè)務(wù)處理，應(yīng)用不同的模塊共享邏輯組件；因此，內(nèi)部的和外部的用戶都可以訪問新的和現(xiàn)有的應(yīng)用系統(tǒng)，通過現(xiàn)有應(yīng)用系統(tǒng)中的邏輯可以擴展出新的應(yīng)用系統(tǒng)。 什么是 C/S和 B/S 要想對“ C/S”和 “ B/S”技術(shù)發(fā)展變化有所了解，首先必須搞清楚三個問題。 保障系統(tǒng)的安全性 ： 在 Client/Server 系統(tǒng)中由于客戶機直接與數(shù)據(jù)庫服務(wù)器進行連接，用戶可以很輕易的改變服務(wù)器上的數(shù)據(jù)，無法保證系統(tǒng)的安全性。 客戶端消腫 ： Client/Server 的客戶端具有顯示與處理數(shù)據(jù)的功能，對客戶端的要求很高，是一個 “ 胖 ” 客戶機。 較低的開發(fā)和維護成本 ： Client/Server 的應(yīng)用必須開發(fā)出專用的客戶端軟件，無論是安裝、配置還是升級都需要在所有的客戶機上實施，極大地浪費了人力和物力。這種三層結(jié)構(gòu)層與層之間相互獨立，任何一層的改變不影響其它層的功能。 仔 細分 析不 難 看出 ， 三層 的 Browser/Server 體 系結(jié) 構(gòu) 是把 二 層Client/Server 結(jié)構(gòu)的事務(wù)處理邏輯模塊從客戶機的任務(wù)中分離出來，由單獨組成的一層來負擔其任務(wù)，這樣客戶機的壓力大大減輕了，把負荷均衡地分配給了Web 服務(wù)器，于是由原來的兩層的 Client/server 結(jié)構(gòu)轉(zhuǎn)變成三層的Browser/Server 結(jié)構(gòu)。它的任務(wù)是接受用戶的請求，首先需要執(zhí)行相應(yīng)的擴展應(yīng)用程序與數(shù)據(jù)庫進行連接，通過 SQL等方式向數(shù)據(jù)庫服務(wù)器提出數(shù)據(jù)處理申請，而后等數(shù)據(jù)庫服務(wù)器將數(shù)據(jù)處理的結(jié)果提交給 Web 服務(wù)器，再由 Web 服務(wù)器傳送回客戶端。 在表示層中包含系統(tǒng)的顯示邏輯，位于客戶端。 本質(zhì)上， Browser/Server也是一種 Client/Server 結(jié)構(gòu)，它是一種由傳統(tǒng)的二層 Client/Server 結(jié)構(gòu)發(fā)展而來的三層 Client/Server 結(jié)構(gòu)在 Web 上應(yīng)用的特例。如下圖所示： ASP 外文翻譯 +原文 xinxiasd 12 這種結(jié)構(gòu)解決了傳統(tǒng) Client/Server 的可擴展問題，既減少了客戶端業(yè)務(wù)邏輯，又降低了客戶端對硬件的要求。 多層的客戶 /服務(wù)器結(jié)構(gòu) 隨著企業(yè)應(yīng)用的擴展，最近又出現(xiàn)了一種新的多層體系結(jié)構(gòu)，它把客戶端應(yīng)用分為兩部分：客戶應(yīng)用和服務(wù)器應(yīng)用。 在服務(wù)器和客戶之間必須有一個協(xié)議，雙方根據(jù)這個協(xié)議進行通信。而服務(wù)器通常執(zhí)行后臺 功能，管理共享的外設(shè)，接受并回答用戶的請求等。從技術(shù)上看，它本身是一個邏輯概念，是指將一個應(yīng)用分解成多個任務(wù)分別執(zhí)行，共同完成整個應(yīng)用任務(wù)的功能。目前在應(yīng)用中常用到的有兩種： C/S 體系結(jié)構(gòu)和 B/S 體系結(jié)構(gòu)。 It can protect data platform efficiently with management visit limits of authority, server database is also safe. Now in my courtyard, ( Intra ) , outer ( Inter ) with Beijing eastern clear big pany law case and the management software of official business is the structural management software of B/S , policemen each working station in local area work pass through WWW browser can realize working business. Especially in JAVA step platform language appearance after, the configuration management software of B/S is more facilitated , is shortcut, efficient. ( 3 ) The management software technology of main stream. ASP 外文翻譯 +原文 xinxiasd 7 The technology of main stream of management software technology is as management thought , have also gone through 3 develop period. First, interface technology goes to Windows graph interface ( or graph user interface GUI ) from last century DOS character interface, till Browser browser interface 3 differences develop period. Secondly, today own the browser interface of puter, is not only visual and is easy to use , what is more major is that any its style of application software based on browser platform is as, make the requirement of choosing a person for the job for operating training not high and software operability is strong , is easy to distinguish。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 ASP 外文翻譯 +原文 xinxiasd 4 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。 Also, customer one side must ASP 外文翻譯 +原文 xinxiasd 2 also have certain hardware and corresponding customer software. There must be a agreement between server and customer, both sides municate according to this agreement. Apply customer / server model in Inter service , the relation between customer and server is not immutable. Some Inter node offers service on the one hand , also gets service on the other hand from other node。 Another part faces every user , is realized by client puter, also namely, client puter is usual to carry out proscenium function , realizes manmachine interaction through user interface , or is the application program of specific conducted user. And server usually carries out the function of backstage supporter , manages the outside request concerning seting up, accepting and replying user that shared. For a puter, it can have double function , is being certain and momentary to carve to act as server , and again bees client puter in another time. Customer / server type puter divide into two kinds, one side who offers service is called as server , asks one side of ser