簡單瀏覽器服務(wù)器三層架構(gòu)畢業(yè)設(shè)計(jì)(論文)外文翻譯

1、<p><b>　　中文1273字</b></p><p>　　學(xué)生畢業(yè)設(shè)計(jì)（論文）外文譯文</p><p>　?。ㄕ捻撁嬲埣禹?；從教務(wù)處主頁下載，統(tǒng)一用A4紙單面激光打?。?lt;/p><p><b>　　外文正文：</b></p><p>　　The definition of the

2、3-tier application：</p><p>　　Normally,3-tier application is that the entire business is divided into：User Interface(UI)、Business Logic Layer(BLL)、Data Access Layer(DAL).The purpose of the distinction between

3、 the level of that in order to "high cohesion, low coupling" thinking.</p><p>　　1、User Interface(UI)：Popular talk is to show to the user interface, that is, users in the use of a system when seen f

4、rom him.</p><p>　　2、Business Logic Layer(BLL)：Issue-specific operation, it can be said that the operation of the data layer, business logic for data processing.</p><p>　　3、Data Access Layer(DAL)

5、：Layer made of the direct operation of the database services for data to add, delete, modify, update, search and so on.</p><p>　　In terms of software architecture design, hierarchical structure is the most c

6、ommon, and most importantly a structure. Microsoft recommended hierarchical structure will generally be divided into three tiers, from bottom to top are: Data Access Layer, Business Logic Tier (or even a field of layer),

7、 indicating that the layer.</p><p>　　The principle of the 3-tier application：</p><p>　　Three levels, the system functionality and business logic to deal with in the Business Logic Tier. The so-c

8、alled three-tier architecture, is in between the client and the database by adding a "middle layer", also known as layer components. Three-tier system mentioned here are not referring to the three physical, rat

9、her than simply place the three machines is the three-tier architecture, it not only B / S application is a three-tier architecture is the logical three-tier three-tier, even if the t</p><p>　　3-tier applica

10、tion system business rules, data access, so check on the legality of the middle layer for processing. Under normal circumstances, the client does not directly interact with the database, but through COM / DCOM communicat

11、ion to establish a connection with the middle layer, middle layer and then interact with the database.</p><p>　　User Interface(UI)：</p><p>　　User Interface(UI) is located in the outermost layer

12、(the top), from the user recently. Used to display data and receive data entered by the user, to provide users with an interactive interface to operate.</p><p>　　Business Logic Layer(BLL)：</p><p&g

13、t;　　Business Logic Layer system architecture is reflected in some of the core values. It concerns mainly concentrated in the formulation of business rules, business processes and business needs to achieve, such as the sy

14、stem design, In other words it is to deal with the areas of systems (Domain) logic, and most of the time, the area known as the Business Logic Tier layer. Martin Fowler ivided the whole structure into three main layers:

15、the presentation Layer, the field layer and the data source laye</p><p>　　Business Logic Tier structure in the system the location of a key, it is data access layer and said intermediate layer, the data exch

16、ange has played a role in connecting. As the layer is a weak-coupling structure between the three levels down the dependence on the bottom to the top is "ignorant" and change the design for the top of the botto

17、m in terms of their call has no effect. If the stratified design, interface design to follow for the idea, then this dependence should be down is a weak depe</p><p>　　Data Access Layer(DAL)：</p><p

18、>　　Data Access Layer: Sometimes also known as the persistence layer, its function is responsible for database access, you can access the database system, binary files, text documents or XML documents.Is to realize tha

19、t a simple table of data Select, Insert, Update, Delete operations. If you want to join the elements of ORM, it will include between objects and data tables of the mapping, as well as the object of persistent entities.&l