J2ME和JAVA領(lǐng)域外文翻譯1

1、附件1：外文資料翻譯譯文j2me和java領(lǐng)域 1.介紹20世紀(jì)70年代以來隨著計算機革命的開始，對計算機先進軟件的需求大大增加，從而可以充分利用功能日益增強的精密的計算機的處理數(shù)據(jù)的能力。c編程語言逐漸成為支柱，使程序員開發(fā)軟件像計算機運行一樣流暢。80年代以來，程序員又目睹了編程語言領(lǐng)域的又一次變革的高潮。c語言的編程能力已經(jīng)不能滿足計算機的技術(shù)發(fā)展的需要。這問題并不是新問題。它造成了一代又一代的編程語言的新老更替。問題是，它使得程序設(shè)計過于復(fù)雜，從而使計算機軟件的設(shè)計，編寫和開發(fā)落后于硬件的發(fā)展。就是這個時候，兩種基于設(shè)計概念的編程語言simula 67和smalltalk（從上世紀(jì)60

2、年代末）帶來了接近編程語言未來前景的循序漸進的步驟。這期間，當(dāng)面向?qū)ο缶幊蹋╫op），與它一種新的編程語言，所謂的c+在程序員中掀起了一場風(fēng)暴。1979年，bjarne stroustrup的在新澤西州的貝爾實驗室增強了c 語言，使其具有面向?qū)ο蟮奶攸c即所謂的c+ 語言 (+是c編程語言增強的承載符號)。c+是一個真正的提高的c編程語言，它開始是一種前置語言，該計劃最初是一種編譯工具。stroustrup建立類的概念（借用了simula 67和smalltalk中的概念），由類則可以創(chuàng)建實例對象。一個類包含數(shù)據(jù)成員和定義對象數(shù)據(jù)和功能的成員函數(shù)。他還介紹了繼承的概念，使一類繼承其他一個或多個類

3、的部分或全部數(shù)據(jù)成員或成員函數(shù)，職能由一個或多個其他類別-所有這些概念就是面向?qū)ο蟮木幊獭?988年由ansi官員將c+標(biāo)準(zhǔn)化。2.走進java正當(dāng)c+作為企業(yè)開發(fā)所選擇的語言時，由于最新的突破性技術(shù)-萬維網(wǎng)的出現(xiàn)，別一種編程語言正在萌芽，并逐漸成熟。幾十年來互聯(lián)網(wǎng)對普通人來說還是個秘密，直到前美國國家科學(xué)基金會（監(jiān)督互聯(lián)網(wǎng)的機構(gòu)）拆除了防止互聯(lián)網(wǎng)商業(yè)化的壁壘。1991年當(dāng)它向商貿(mào)開放時，互聯(lián)網(wǎng)幾乎是政府機構(gòu)和學(xué)術(shù)團體的專利。一旦商業(yè)化的障礙被取消，萬維網(wǎng)提供的幾個服務(wù)，在互聯(lián)網(wǎng)上成為虛擬社區(qū)中心，游客可以得到幾乎任何的免費的資訊并瀏覽數(shù)以千計的虛擬商店。 瀏覽器加強了萬維網(wǎng)。瀏覽器轉(zhuǎn)換將用h

4、tml編寫的ascii文本文件轉(zhuǎn)化成為一個互動的顯示功能，并可以任何計算機上編譯運行。只要瀏覽器是和html和http兼容的正確版本，在任何電腦上運行的瀏覽器可以使用相同的html文件，而不是指定為某一特定類型的計算機，而在以前是聞所未聞的。而c或c+是依賴于機器的，并且不能運行于不同機器上，除非是重新編譯。互聯(lián)網(wǎng)的成功使人們將重點放在發(fā)展獨立于機器的編程語言上。和同年在互聯(lián)網(wǎng)上被商品化，科技工作者詹姆斯戈斯林，帕特里克諾頓，和麥克謝里登花了18個月發(fā)展規(guī)劃，并在1995年向公眾發(fā)布，他們所謂的oak，后來改名為java。java 在1991年和1995年期間經(jīng)歷了無數(shù)次的變革。那個時候，在s

5、un公司的許多其他科技人員對該語言的發(fā)展做出了重大貢獻。喬恩，阿瑟范霍夫，喬納森佩恩，耶林，添佩爾都分享了成功的喜悅。 雖然java是和互聯(lián)網(wǎng)密切相關(guān)，但開始是為了開發(fā)一種可以嵌入到電子器件中去的軟件的編程語言，而無論所用裝置的cpu類型。這也是眾所周知的所謂嵌入式翻譯 java平臺。java團隊從sun成功地建立了一種可移植性的編程語言，電腦程序員進行了首次編程，一些已經(jīng)實現(xiàn)。他們的成功遠(yuǎn)遠(yuǎn)超出了他們的夢想。同樣可以使java程序進行在各種可移植的電子裝置上，也可以使java程序在安裝了microsoft windows，unix和macintosh的計算機上運行。這個時機很完美。因特網(wǎng)/內(nèi)

6、部網(wǎng)已使美國企業(yè)為符合公司成本效益，而開發(fā)應(yīng)用于公司的可移植程序的興趣。java已被證明可以作為一種成功開發(fā)與機器無關(guān)的應(yīng)用程序的編程語言。 3.java虛擬機寫java程序和寫c+程序是相似的，這程序員可以編寫：包含指示的源代碼，成為一個編輯器，或在一個綜合發(fā)展環(huán)境中對源代碼進行編譯。不過，這也就是java和c+一部分的方式。該編譯和鏈接的過程中一個c+程序的結(jié)果可以運行在一個適當(dāng)?shù)目蓤?zhí)行的機器上。與此相反，java編譯器則將java源代碼轉(zhuǎn)換成字節(jié)，即由java虛擬機（jvm）執(zhí)行。機器的具體指示，則不會包括在字節(jié)中。相反，他們已經(jīng)包括在jvm的，這是屬于具體機器的。這意味著該字節(jié)可能包含

7、的c+程序要翻譯的指令要少。分段嗎？4.未來的世界：j2mejava是在消費和工業(yè)產(chǎn)品中作為一種編程語言創(chuàng)建程序嵌入式系統(tǒng)微機發(fā)現(xiàn)的開始，如那些用來控制汽車和家用電器的微機。在20世紀(jì)90年代初，開發(fā)團隊在sun的工作利用java以解決幼稚的嵌入式電腦市場的編程的需要，但這種努力是更側(cè)重于來自互聯(lián)網(wǎng)的吸引力的機會。在世紀(jì)交替之年由于這些機會已得到解決，一種新的便攜式通信帶來了其他設(shè)備的機會。從語音通信設(shè)備的語音到文本通信設(shè)備。而便攜式電子電話簿演變成個人數(shù)碼助理。在這時候，芯片制造商所推出的新產(chǎn)品，其目的是為了從桌上型電腦轉(zhuǎn)移計算能力到移動的小型電腦控制的燃?xì)馑?，電纜電視盒，和其他組合的其他

8、電器。為下一步的演變的java的時機是合理的。不過，不是java 與額外的空氣污染指數(shù)加強，在sun公司的該小組，即java 組織化翻譯計劃，拆除均采用java編程語言和java虛擬機。他們從嵌入式系統(tǒng)和微機設(shè)備剝離下來的java的api和jvm到最低限度編碼須提供情報。由于這些設(shè)備資源方面的限制強加的硬件設(shè)計，這是必要的。他們的努力結(jié)果是j2me的。j2me是減少了java api和java虛擬機是設(shè)計用來運作稀疏可用的資源在新的品種的嵌入式計算機和微機的版本。5.組織j2me傳統(tǒng)計算設(shè)備需要使用標(biāo)準(zhǔn)相當(dāng)?shù)挠布渲?，如顯示器，鍵盤，鼠標(biāo)和大量的記憶和永久儲存。不過，其中新一代的計算設(shè)備缺乏的

9、硬件配置的連續(xù)性。有些設(shè)備不具有顯示屏，永久儲存，鍵盤，或鼠標(biāo)。其中小的計算設(shè)備的記憶提供情況是不一致的。缺乏統(tǒng)一標(biāo)準(zhǔn)的硬件配置之間的小型計算設(shè)備的構(gòu)成是一項艱巨的挑戰(zhàn)java 組織化翻譯的計劃則是為jvm和j2me的小型計算設(shè)備制定標(biāo)準(zhǔn)。許多不同種的小的j2me的計算設(shè)備，包括可視電話，數(shù)字機頂盒用于有線電視，手機和個人數(shù)字助理，所面臨的挑戰(zhàn)是java 組織化翻譯的計劃是建立一個可以對小的無標(biāo)準(zhǔn)的計算設(shè)備實施的java標(biāo)準(zhǔn)。6.j2me和無線設(shè)備隨著手機等無線設(shè)備的大量出現(xiàn)和功能的逐漸完善，對運行在這樣的設(shè)備上的軟件的要求量也越來越大。消費者和企業(yè)都要擴大移動通信設(shè)備的功能，使其從傳統(tǒng)的語音

10、通信過渡到類似于筆記本電腦和個人電腦的功能，使他們可以傳送和接收電子郵件，存儲和檢索的個人資料，執(zhí)行精密的計算和玩游戲。開發(fā)商，移動通信設(shè)備制造商，和移動網(wǎng)絡(luò)供應(yīng)商現(xiàn)正急欲填補這方面的需求，但有是一個嚴(yán)重的障礙：移動通信設(shè)備利用許多不同的應(yīng)用平臺和經(jīng)營調(diào)整代碼，為一設(shè)備開發(fā)的代碼將無法運行在另一個設(shè)備上。移動通信設(shè)備缺乏一個標(biāo)準(zhǔn)的應(yīng)用平臺及作業(yè)系統(tǒng)，這使得應(yīng)用開發(fā)移動通信設(shè)備，促進經(jīng)濟發(fā)展有些冒險。 缺乏標(biāo)準(zhǔn)，就是沒有新的計算或任何技術(shù)開發(fā)。在傳統(tǒng)意義上，硬件設(shè)備制造商的嘗試產(chǎn)品遍及市場，并執(zhí)行他們的自己的專有標(biāo)準(zhǔn)作為事實上的業(yè)界的標(biāo)準(zhǔn)。許多暴發(fā)戶成功的情況和微軟一樣。其他時候，業(yè)界領(lǐng)袖則組成

11、一個財團，例如java 組織化翻譯計劃，集體制定一種標(biāo)準(zhǔn)。 無線應(yīng)用協(xié)議（wap）行動網(wǎng)際網(wǎng)路論壇成為初步創(chuàng)建無線技術(shù)標(biāo)準(zhǔn)的產(chǎn)業(yè)集團。wap 論壇創(chuàng)造了移動通信設(shè)備標(biāo)準(zhǔn)，被稱為thewap標(biāo)準(zhǔn)。thewap標(biāo)準(zhǔn)是一個提高的html，xml的，和tcp/ip 的一個組成部分，這個標(biāo)準(zhǔn)是無線標(biāo)記語言規(guī)范而組成的，融合了html和xml。wmlscript 是一種剝奪式版本的javascript。7.j2me 應(yīng)用翻譯程序j2me的應(yīng)用程序稱為midlet幾乎可以運行在任何實現(xiàn)了jvm和midp移動通信設(shè)備上。這鼓勵開發(fā)商投資時間和金錢在建設(shè)移動通信設(shè)備上，而不需要擔(dān)心該應(yīng)用是設(shè)備依賴的風(fēng)險。不過，

12、j2me是不會被視為更換為wap的規(guī)格，因為兩者都是互補的技術(shù)。開發(fā)商的申請是根據(jù)客戶要求的基礎(chǔ)繼續(xù)使用wml和wmlscript。開發(fā)商轉(zhuǎn)向j2me的較重的客戶，需要對移動通信設(shè)備進行復(fù)雜的處理。附件2：外文原文（復(fù)印件）java 2 micro edition and the world of java1 introductionthe computer revolution of the 1970s increased the demand for sophisticated computer software to take advantage of the ever-increasi

13、ng capacity of computers to process data.the c programming language became the linchpin that enabled programmers tobuildsoftware that was just as robust as the computer it ran on.as the 1980s approached, programmers were witnessing another spurt in the evolutionof programming language. computer tech

14、nology advanced beyond the capabilities of the c programming language. the problem wasnt new. it occurred previously and caused the demise of generations of programming languages. the problem was thatprograms were becoming too complicated to design, write, and manage to keep up with the capabilities

15、 of computers. it was around this time that a design concept based on simula 67 and smalltalk (from the late 1960s) movedprogramming to the next evolutionary step. this was the period when object-oriented programming (oop), and with it a new programming language called c+, took programmers bystorm.i

16、n 1979, bjarne stroustrup of bell laboratories in new jersey enhanced the cprogramming language to include object-oriented features. he called the language c+. (the + is the incremental operator in the c programming language.) c+ is truly an enhancement of the c programming language, and it began as

17、 a preprocessor language that was translated into c syntax before the program was processed by the compiler.stroustrup built on the concept of a class (taken from simula 67 and smalltalk), from which instances of objects are created. a class contains data members and member functions that define an

18、objects data and functionality. he also introduced the concept of inheritance, which enabled a class to inherit some or alldata members and member functions from one or more other classesall of which complements the concepts of object-oriented programming.by 1988, ansi officials standardized stroust

19、rups c+ specification.2 enter javajust as c+ was becoming the language of choice for building industrial-strength applications, another growth spurt in the evolution of programming language was budding, fertilized by the latest disruptive technologythe world wide web.the internethad been a well-kept

20、 secret for decades before the national science foundation (who oversaw the internet) removed barriers that prevented commercialization. until 1991 when it was opened to commerce, the internet was the almostexclusive domain ofgovernment agencies and the academic community. once the barrier to commer

21、cialization was lifted, the world wide webone of several services offered on the internet became a virtual community center where visitors could get free information about practically anything and browse through thousandsof virtual stores.browsers power the world wide web.a browser translates ascii

22、text files written in html into an interactive display that can be interpreted on any machine. as long as the browser is compatible with the correct version of html and http implementation, any computer running the browser can use the same html document without having to modify it for a particular t

23、ype of computer, whichwas something unheard of at the time. programs written in c or c+ are machine dependent and cannot run on a different machine unless the program is recompiled.the success of the internet gave renewed focus to developing a machine-independent programming language. and the same y

24、ear the internet was commercialized, five technologists at sun microsystems set out to do just that. james gosling,patrick naughton, chriswarth, ed frank, and mike sheridan spent 18 months developingthe programming language they called oak, which was renamed java when this new language made its debu

25、t in 1995. java went through numerous iterations between 1991 and 1995, during which time many other technologists at sun made substantialcontributions to the language. these included bill joy, arthur van hoff, jonathan payne, frank yelin, and tim lindholm.although java is closely associated with th

26、e internet, it was developed as a language for programming software that could be embedded into electronic devicesregardless of the type of cpu used by the device. this is known as the embeddedjava platform and is in continuous use today for closed systems.the java team from sun succeeded in creatin

27、g a portable programming language,something that had eluded programmers since computers were first programmed. their success, however, was far beyond their wildest dreams. the same concept used to make java programs portable to electronic devices also could be used to makejava programs run on comput

28、ers running microsoft windows, unix, andmacintosh.timing was perfect. the internet/intranet had whetted corporate americas appetite for cost-effective, portable programs that could replace mission-criticalapplications within the corporation. and java had proven itself as a programming language used

29、to successfully develop machine-independent applications.3 java virtual machinewritingjava programs is similar to writing c+ programsin that the programmer writes source code that contains instructions into an editor,or in an integrated developmentenvironment, and then the source code is compiled.ho

30、wever, thats where java andc+part ways. the compiling and linking processof a c+ program results in an executablethat can be run on an appropriatemachine.in contrast, the java compiler converts javasource code into bytecode that is executed by the java virtual machine (jvm).machine-specific instruct

31、ions are not included in bytecode. instead, they alreadyreside in the jvm, which is machine specific. this means that the bytecode might contain fewer instructions that need to be translated than a comparable c+program.although the java compiler generates bytecode that must be interpreted by thejvma

32、t run time, the number of instructions that need translation are usually minimal andhave already been optimized by the java compiler.4 back to the future: j2me remember that java began as a programming language to create programs for embedded systemsmicrocomputers found in consumer and industrial pr

33、oducts such asthose used to control automobiles and appliances. the development team at sunworked on java in the early 1990s to address the programming needs of the fledgling embedded computer market, but that effort was sidetracked by more compelling opportunities presented by the internet.as those

34、 opportunities were addressed, a new breed of portable communicationsdevices opened other opportunities at the turn of the century. cell phones expanded4 j2methe completereference from voice communications devices to voice and text communications devices. pocket electronic telephone directories evol

35、vedinto personal digital assistants. chipmakers were releasing new products at this time that weredesigned to transfer computing power from a desktop computer intomobile small computers that controlled gas pumps, cable television boxes, and an assortment of other appliances.the time was right for th

36、e next evolution of java. however, instead of beefing up java with additional apis, the team at sun, along with the java community process program, dismantled both the java programming language and the javavirtual machine. theystripped down java apis and the jvm to the minimum coding required to pro

37、videintelligence to embedded systems and microcomputer devices. this was necessary because of resource constraints imposed upon the hardwaredesign of these devices. theresult of their efforts is j2me. j2me is a reduced version of the java api and java virtual machine that is designed to operate with

38、inthe sparse resources available in the new breed of embedded computers and microcomputers.5 how j2me is organizedtraditional computing devices use fairly standard hardware configurations such as a display, keyboard,mouse, and large amounts of memory and permanent storage.however, the new breed of c

39、omputing devices lacks hardware configuration continuity among devices. some devices dont have a display, permanent storage, keyboard,or mouse. and memory availability is inconsistent among small computing devices. the lack of uniform hardware configuration among the small computing devices poses a

40、formidable challenge for the java community process program,which is chargedwith developing standards for the jvm and the j2me for smallcomputing devices.j2me must service many different kinds of small computing devices, includingscreenphones, digital set-top boxes used for cable television, cell ph

41、ones, and personal digital assistants. the challenge for the java community process program is to develop a java standard that can be implemented on small computing devices that have nonstandard hardware configurations. the java community process program has used a twofold approach to addressing the

42、 needs of small computing devices. first, they defined the java run-time environment and core classes that operate on each device. this is referred to as the configuration. a configuration defines the java virtual machine for a particular small computing device. there are two configurations, one for

43、 handheld devices and the other for plug-in devices. next, the java community process program defined a profile for categories of smallcomputing devices. a profile consists of classes that enable developers to implement features found on a related group of small computing devices.6 j2me and wireless

44、 deviceswith the dramatic increase and sophistication of mobile communications devicessuchas cell phones came demand for applications that can run on those devices. consumers and corporations want to expand mobile communications devices from voice communications to applications traditionally found o

45、n laptops and pcs. they want tosend and receive email, store and retrieve personal information, perform sophisticated calculations, and play games.developers, mobile communications device manufacturers, and mobile network p roviders are anxious to fill this need, but there is a serious hurdle: mobil

46、e communications devices utilize a number of different application platforms and operating systems.without tweaking the code, an application written for one device cannot runon another device.mobile communications devices lack a standard application platform and operating system, which has made deve

47、loping applications for mobile communications devices a risky economic venture for developers.the lack of standards is nothing new to computing or to any developing technology.traditionally, manufacturers of hardware devices try to corner the market and enforce their own proprietary standard as the

48、de facto standard for the industry. usually one upstart succeeds, as in the case of microsoft. other times, industry leadersform aconsortium, such as the java community process program, to collectively develop a standard.the wireless application protocol (wap) forum became the initial industry group that set out to