1、UNIT 28Component-Based DevelopmentA Revolution inApplication DevelopmentComponent-Based Development(CBD)will revolutionize the software industry.1Unlike recent trends such as objects and client/server,it is not just another flavor of distributed computing,but an extensible architecture to support al
2、l life cycle computing metaphor,including design,development and deployment.UNIT 28Because of its high levels of reuse and interoperability,CBD will influence every dimension of application composition,including all types of clients,application servers and database severs,and will have a profound im
3、pact on all aspects of application development.CBDs predecessor was object oriented(OO)development.Objects were the industrys first stab at delivering high levels of reuse.2But the unsophisticated nature of OO development environments and the lack of a common infrastructure for addressing object int
4、eroperability hindered their mainstream adoption.3OO development was too far ahead of its time and lacked infrastrutural support from the software industry.UNIT 28CBD redefines objects in the context of a standardized infrastructure for interoperability frameworks for the construction and assembly o
5、f applications,and pre built components that subscribe to component infrastructures and frameworks.The infrastructural dimension of the component architecture is the catalyst to achieving the reuse and interoperability that undermined OO development.4This infrastructure,along with the availability C
6、BD frameworks that enable component design,construction and assembly(rather than just being an environment for visual programming),will forever change how applications are developed.UNIT 28The evolution is from first-generation(2-tier)and secondgeneration(3-tier)client/server to CBD.Because newer ph
7、ases such as 3tier client/server and CBD essentially subsume the functionality of older ones,the migration of system is theoretically possible,although typically it is difficult due to the proprietary constructs of earlier products.As a result,many applications built with older products simply becom
8、e another class of legacy system.UNIT 28CBD can be divided into three stages:monolithic,distributed and persistent overtime,certain standards will become pervasive,core services will become commercial,and the infrastructural dimension of CBD will ensure that portability and interoperability requirem
9、ents are met.Component frameworks play a key role in defining the design,development and deployment paradigm,usage metaphor,infrastuctural extensions and pre built components for application development.Frameworks,which work with the component infrastructure to provide a complete development environ
10、ment,are the most important dimensionof CBD.UNIT 28The first stage of CBD is the era of monolithic components,a seeming oxymoron that describes the adolescent state of components today.5None of todays component standards and frameworks have resolved the portability and interoperability issues that w
11、ould allow components to be distributed or persistent across multiple vendor frameworks,standards for CBD are being established but standardized infrastructural components do not exist.6As a result,frameworks are being introduced with a high content level of proprietaryinfrastructuralcomponents.UNIT
12、 28New Words revolutionize v.使发生革命extensible adj.广泛的metaphor n.理念reuse v.重新使用interoperability n.互用性dimension n.方面composition n.构成profound adj.深刻的predecessor n.前身oriented adj.导向的hinder v.阻碍UNIT 28adoption n.采用redefine v.重新定义assembly n.集合,装配subscribe v.赞成catalyst n.催化剂subsume v.包含,包容functionality n.功能
13、性theoretically adv.理论上地monolithic n.单片电路pervasive v.普遍深入的portability n.可携带,轻便paradigm v.范例era n.时期persistent adj.一贯的,持续的 UNIT 28Phrases and Expressions because of 因为have an impact on 对有影响be ahead of 在之前not.but 不是而是along with 连同rather than 而不是due to 由于as a result 因此UNIT 28The Explanation of Difficult
14、 Statements 1.Unlike recent trends such as objects and client/server,its not just another favor of distributed company,but an extensive architecture to support a life cycle computing metaphor,including design,development and deployment.分析分析:“Unlike recent trends such as objects and client/server”为介词
15、短语,在句中作状语;主句“not.but”译为“不是而是”。句意句意:与诸如(面向)对象和客户机/服务器等最新趋势不同,CBO不只是一种分布计算新花样,而是一种广泛的体系结构,支持整个生命周期计算的理念,包括设计、开发和发布。UNIT 282.But the unsophisticated nature of OO development environments and the lack of a common infrastructure for addressing object interoperability hindered their main steam adoption.分析
16、分析:此句中主语部分较长,给翻译造成了一定的难度。翻译时可采用“转译法”和“分译法”。句意句意:但是OO开发环境本质不够完善,缺乏解决对象互用性的公共基础设施,这些因素防害了它们成为主流产品。UNIT 282.But the unsophisticated nature of OO development environments and the lack of a common infrastructure for addressing object interoperability hindered their main steam adoption.分析分析:此句中主语部分较长,给翻译造
17、成了一定的难度。翻译时可采用“转译法”和“分译法”。句意句意:但是OO开发环境本质不够完善,缺乏解决对象互用性的公共基础设施,这些因素防害了它们成为主流产品。UNIT 284.This infrastructure,along with the availability of CBD frameworks that enable component design,construction and assembly(rather than just being an environment for visual programming),will forever change how appli
18、cations are development.分析分析:此句的主语部分亦较长,其中“介词along with+名词”不影响句中主语与谓语动词的一致关系。例如:This man along with his sons always catches the large fish.句意句意:这种基础设施加上CBD架构的可获得性将永远改变应用程序的开发,而CBD架构能实现组件的设计、编制和装配(不只是一种直观编程的环境)。UNIT 285.None of todays component standards and frameworks have resolved the portability a
19、nd interoperability issues that would allow components to be distributed or persistentacross multiple vendor frameworks.分析分析:“none of+名词”作主语时,谓语动词的单复数取决于介词of后面的名词的单复数。例如:None of the evidence points to his guilt.None of our students were involved.句意句意:今天还没有一种组件标准和架构已经解决了可移植性和互用性的问题,而这些问题的解决将允许组件在多个厂商
20、的架构上实现分布式或持续式。UNIT 286.As a result,frameworks are being introduced with a high content level of proprietary infrastructural components.分析分析:“are being introduced”为现在进行时的被动语态,例如:The experiment is being done this week.句意句意:因此,架构正在随着专有基础设施组件的高满意程度一起引入。UNIT 28Grammar Translation Skills 词词 类类 转转 译译 法法由于词
21、的使用范围和表达方式不一样,原文中某词类的词,在译成汉语时不能“对号入座”,可以(有时必须)转为另一种词类,否则就难以清晰表达原文的意义,或者违背汉语的表达习惯。常见的几种转译的表达方式如下:1.转译成汉语动词转译成汉语动词汉语中使用动词比英语多,也比较灵活,有时一个短句就用了好几个动词。因此英语中名词、介词和副词均可转译为汉语动词。例如:(1)He is a good observer.他善于观察。UNIT 28(2)After the accomplishment of the present task,there will follow a more arduous one.现在的任务完
22、成后,还有更艰巨的任务。(3)At last,he whispered a hurried good-bye to his host and darted toward the door.最后,他赶紧向主人轻声道别,然后向门口跑去。(4)We can see the stars in the sky very clearly with a telescope.我们用一架望远镜就可以清楚地看到天空中的星星。(5)I opened the window to let the fresh air in.我打开窗户让新鲜空气进来。UNIT 282.转译成汉语名词转译成汉语名词英语中有些动词的概念很难直
23、接用汉语动词表现出来,这时可以转译成汉语的名词。例如:(1)The electronic computer is characterized by its accurate and computation.电脑的主要特征是计算又快又准。(2)Energy is commonly defined as the capacity of a system to do work.能的一般定义是系统做功的能力。(3)He impressed me favorably.他给我很好的印象。(4)Gases differ from solids in that the former have greater
24、compressibility than the latter.气体和固体的区别在于前者比后者有更大的可压缩性。UNIT 283.转译成汉语形容词转译成汉语形容词由于动词可转译成名词,原来修饰动词的副词也相应地转译成形容词。例如:(1)This waveguide tube is chiefly characterized by its simplicity of structure.这种波导管的主要特点是结构简单。(2)He impressed me deeply.他给我留下了深刻的印象。UNIT 284.转译成汉语副词转译成汉语副词由于英语名词转译成汉语的动词,所以原来修饰名词的形容词自然
25、就要译成汉语的副词。例如:We must make full use of existing technical equipment.我们必须充分地利用现有的技术设备。UNIT 28Exercises.Fill in the blanks according to the text:(1)CBD will influence every dimension of application composition,including all types of clients,_,and will have a profound impact on all aspects of applicatio
26、n development.(2)CBDs predecessor was _development.(3)The _of the component architecture is the catalyst to achieving the reuse and interoperability that undermined OO development.(4)CBD can be divided into three stages:_.(5)_,which work with the component infrastructure to provide a complete develo
27、pment environment,are the most important dimension of CBD.UNIT 28.Decide whether each of the following statements is true or false according to the text:(1)Component-Based Development(CBD)will revolutionize the software industry.(2)Component-Based Development(CBD)is just another flavor of distribute
28、d computing.(3)Objects were the industrys second stab at delivering high levels of reuse.(4)The evolution is from first-generation(-tier)and secondgeneration(3-tier)client/server to CBD.(5)The third stage of CBD is the era of monolithic components,a seeming oxymoron that describes the adolescent sta
29、te of components today.UNIT 28.Translate the following sentences into Chinese:(1)His music was an exciting mixture of country music and the blues.(2)I found him at his book in the library.(3)The book aims at giving a general outline of the subject.(4)We were wrongly informed.(5)The man I saw at the
30、party looked and talked like an American.UNIT 28.Translate the following paragraph into Chinese:The persistent component stage occurs when virtually all the infrastructure associated with CBD is commercialized.Commercialization encourages the growth of service providers who broker many types of comp
31、onents,which are easily customized by business rules.This elevates the concept of leasing in the software market;in this stage,most components are reused,leased or purchased by consumers.Component sign is the focal point of CBD activities for those that manufacture components.Toolcentric issues(life
32、 cycle coverage,development paradigm,usage metaphor and availability of prebuilt components)become key product differences.UNIT 28 Reading Materials Component-Based Development-A Revolution in Application DevelopmentIn the next stage,monolithic components give way to distributed components maturing
33、component standards and new infrastructural components permit component interoperability and portability.Frameworks,now freed of specific infrastructural tasks,focus more on the development paradigm and support more aspects of component life cycle.The increased richness of component standards and fr
34、ameworks brings support for more granular components,with many vendors marketing componentUNIT 28libraries.In this stage,the scope of CBD expands to include component design.Component based design changes the CBD paradigm from physical construction logical design.The increased granularity of compone
35、nts,their rich and varied supply,and the inclusion of design metadata in the components themselves improves CBD and validates it as the application development paradigm.UNIT 28The persistent component stage occurs when virtually all the infrastructure associated with CBD is commercialized.Commercial
36、ization encourages the growth of service providers who broker many types of components,which are easily customized by business rules.This elevates the concept of leasing in the software market;in this stage,most components are reused,leased or purchased by consumers.Component sign is the focal point
37、 of CBD activities for those that manufacture components.Tool-centric issues(life cycle coverage,development paradigm,usage metaphor and availability of prebuilt components)become key product differences.UNIT 28Now,application qualitymeasurable for the first time becomes a competitive feature.Framew
38、orks continue as the focal point for enabling application development due to the control over the development paradigm.Old functionality moves“down”and may even become part of the operating system.New functionality is divided into process functionality,which resides in the frameworks,and domain spec
39、ific functionality(along with domain content,which is embodied in component libraries).The persistent component phase is marked by cross-vendor interoperability without the requirement for specific bilateral technology relationships.UNIT 28This distributed computing model,which relies on a synergist
40、ic relationship between component standards,infrastructure and frameworks,operates most efficiently when vendors collaborate on the core infrastructural dimensions of CBD.The faster this collaboration occurs,the faster CBD will mature.Such collaboration implies agreement on APIs,core languages,found
41、ation classes and domain specific data definitions.Once the infrastructure is agreed on,competition can revolve around factors such as features,quality and cost-to-use.This evolution to a standardsbased infrastructure is accelerating as vendor attitudes about the base for market competition mature.U
42、NIT 28The Adaptive Component Architecture(ACA)framework,which Sybase unveiled I April,represents both a unification of the companys products and an ongoing evolution of its product families in the direction of CBD.With ACA,the goal Sybase is to deliver a framework that sets new standards for complet
43、eness,openness,flexibility and performance.UNIT 28New Words and Expressions component-based 基于组件的monolithic components 单独式组件infrastructure n.基础结构,基础设施distributed component 分布式组件interoperability and portability 互操作性与可移植性granular adj.粒度的component based design 基于组件的开发development paradigm 开发范式commercialize vt.使商业化,(企图)从当中赚钱elevate vt.举起,提高UNIT 28bilateral adj.两边的,双边的,有两边的,在两边的mature vt.vi.使成熟,成熟core languages 核心语言foundation classes 基础类domain specific data 域特定元素cost-to-use 成本ACA(Adaptive Component Architecture)自适应组件体系结构veil vt.以面纱遮掩,隐蔽
