java介紹外文翻譯

1、<p><b>　　外文原文</b></p><p>　　Introduction to Java</p><p>　　autor：Martin Ngobye.</p><p>　　source：Computing Static Slice for Java Programs</p><p>　　Java is

2、 designed to meet the challenges of application development in the context of heterogeneous, network-wide distributed environments. Paramount among these challenges is secure delivery of applications that consume the min

3、imum of system resources, can run on any hardware and software platform, and can be extended dynamically.</p><p>　　Java originated as part of a research project to develop advanced software for a wide variet

4、y of network devices and embedded systems. The goal was to develop a small, reliable, portable, distributed, real-time operating platform. When the project started, C++ was the language of choice. But over time the diffi

5、culties encountered with C++ grew to the point where the problems could best be addressed by creating an entirely new language platform. Design and architecture decisions drew from a varie</p><p>　　The desig

6、n requirements of Java are driven by the nature of the computing environments in which software must be deployed.</p><p>　　The massive growth of the Internet and the World-Wide Web leads us to a completely n

7、ew way of looking at development and distribution of software. To live in the world of electronic commerce and distribution, Java must enable the development of secure, high performance, and highly robust applications on

8、 multiple platforms in heterogeneous, distributed networks.</p><p>　　Operating on multiple platforms in heterogeneous networks invalidates the traditional schemes of binary distribution, release, upgrade, pa

9、tch, and so on. To survive in this jungle, Java must be architecture neutral, portable, and dynamically adaptable.</p><p>　　The Java system that emerged to meet these needs is simple, so it can be easily pro

10、grammed by most developers; familiar, so that current developers can easily learn Java; object oriented, to take advantage of modern software development methodologies and to fit into distributed client-server applicatio

11、ns; multithreaded, for high performance in applications that need to perform multiple concurrent activities, such as multimedia; and interpreted, for maximum portability and dynamic capabilities.</p><p>　　To

12、gether, the above requirements comprise quite a collection of buzzwords, so let’s examine some of them and their respective benefits before going on.</p><p>　　What’s completely new is the manner in which Jav

13、a and its run-time system have combined them to produce a flexible and powerful programming system..</p><p>　　Developing your applications using Java results in software that is portable across multiple mach

14、ine architectures, operating systems, and graphical user interfaces, secure, and high performance, With Java, your job as a software developer is much easier—you focus your full attention on the end goal of shipping inno

15、vative products on time, based on the solid foundation of Java. The better way to develop software is here, now, brought to you by the Java language platform.</p><p>　　Very dynamic languages like Lisp, TCL,

16、and SmallTalk are often used for prototyping. One of the reasons for their success at this is that they are very robust—you don’t have to worry about freeing or corrupting memory.</p><p>　　Similarly, program

17、mers can be relatively fearless about dealing with memory when programming in Java, The garbage collection system makes the programmer’s job vastly easier; with the burden of memory management taken off the programmer’s

18、shoulders, storage allocation errors go away. Another reason commonly given that languages like Lisp, TCL, and SmallTalk are good for prototyping is that they don’t require you to pin down decisions early on—these langua

19、ges are semantically rich.</p><p>　　Java has exactly the opposite property: it forces you to make explicit choices. Along with these choices come a lot of assistance—you can write method invocations and, if

20、you get something wrong, you get told about it at compile time. You don’t have to worry about method invocation error.</p><p>　　The Java beginner must grasp 30 basic concepts</p><p>　　Basic conc

21、ept</p><p>　　1.In OOP the only relations is what the object’s interface, such as the computer seller he leaves alone internal structure of electrical source, but he is only concerned about that whether the p

22、ower will be supplied to you, also so long as know can or not but is not how and why.All procedures are make up of certain attribute and the behavior object, the different object visit invokes through the function invoca

23、tion, between the object all intercommunion are invoke through the method invocation, </p><p>　　2.In OOP the most important thought is class, the class is the template ,is a blueprint, construct an object fr

24、om a class, namely construct an instance of the class.</p><p>　　3. Encapsulation: is that combines the data and the behavior in a package) and hides the data the realization process to the object user, in an

25、 object data is called its instance field.</p><p>　　4.Through expands a class to obtain a new class is called inheritance, but all classes are constructed by the object super root class of expansion, super r

26、oot class of as follows can make the introduction.</p><p>　　5.Object 3 principal characteristics</p><p>　　Behavior--- explained this object can make what.</p><p>　　Tate--- when the

27、object exerts the method object reflection.</p><p>　　Dentity--- and other similar behavior objects discrimination symbols.</p><p>　　Each object has only indentity and among three characteristics

28、 they affect mutually.</p><p>　　6. Relations among classes:</p><p>　　Use-a:Dependent relation</p><p>　　Has-a:Polymerization relation</p><p>　　Is-a: inheritor relation -

29、- example:A class has inherited B class, this time A class not only has B class of method, but also has its own method(Individuality exists in general character)</p><p>　　7.Structure object use structure:Str

30、ucture proposing, the structure is one special method, the structure object and to its initialization.</p><p>　　Example:A Data class of structure calls Data</p><p>　　New Data () --- structure a

31、new object, also initialize current time.</p><p>　　Data happyday=new Data () --- an object evaluates an variable happyday, thus enables this object to be used many times, here be stated the cause variable an

32、d the object variable are different.</p><p>　　New returns the value is a quotation.</p><p>　　Constructor characteristic:The constructor may have 0, one or many parameters</p><p>　　T

33、he constructor and the class have the same name</p><p>　　A class may have many constructor. The constructor has not returned value</p><p>　　The constructor always be together used with the new o

34、perator</p><p>　　8. Over loading: When many methods have the same name when includes the different parameter, then has the over loading Which method does the compiler have to choose invokes.</p><p

35、>　　9.Package : Java allow one or many classes to become together as group, is called package, to organizing duty easily, the standard Java storehouse divides into many packages Java.Lang java.Util java, net and so on,

36、 the package is layered and all java packages are in java and in a javax package.</p><p>　　10. Extendable thought: permit to construct new class on existing classes , when you extend the class which already

37、existed, then you reuse this class of method and the field, at the same time you might add the new method and the field in the new class.</p><p>　　11.Expandable class:The expandable class fully manifested is

38、-a to extend the relations The form is:Class (subclass) extends (base class).</p><p>　　12. Multi-modality: In java, the object variable is multi-modality But in java does not support multiple extend. </p&

39、gt;<p>　　13.Dynamic combine: the mechanism of invoking object method mechanism.</p><p>　　1) compiler examines object statement type and method name.</p><p>　　2) the compiler examines that

40、 method invokes parameter type.</p><p>　　3) static combine: If the method type is priavte static the final ,compiler can accurately know which method should invoke.</p><p>　　4) when the procedur

41、e runs and uses dynamic combine to invoke a method, the method edition which then hypothesized machine must invoke x the object actual type which aims at to match.</p><p>　　5) dynamic combine: is a very impo

42、rtant characteristic, it can cause the procedure to change again may expand but does not need to translate has saved the code.</p><p>　　14.Final class:In order to prevent other people derive the new class fr

43、om yours class, this class is cannot expanded.</p><p>　　15.The dynamic invocation spend longer time than the static invocation expenditure.</p><p>　　16.Abstract class:Stipulated or many abstract

44、 methods class of itself must define is abstract.</p><p>　　Example: Public abstract string getDescripition</p><p>　　17.In Java each class is be extended by object class.</p><p>　　18

45、. equal and toString method in object class .</p><p>　　Equal uses in testing an object is whether equal with another object.</p><p>　　ToString returns to represent this object the string of char

46、acter, each class can nearly over loading this method, in order to returns to the current condition the correct expression.</p><p>　　(The toString method is a very important method)</p><p>　　19.

47、General programming:Any class of type all values all may replace with a object class of variable. </p><p>　　20.The array tabulates: The ArrayList dynamic array tabulates, is a class of storehouse, defines in

48、 java.In uitl package, but automatic control array size.</p><p>　　21.in class and class of object ,getclass method returns to the class type an example, when the procedure start contains can increase in the

49、main method class, hypothesized confidential increase all classes which he needs, each increase class all must increase the class which it needs.</p><p>　　22.The class: class might dynamic operate the java c

50、ode for the compilation the procedure to provide the formidable function reflection, this function was JavaBeans is specially useful, the use reflected Java to be able to support the VB programmer to be familiar with the

51、 use the tool.</p><p>　　procedure of analysis class ability is called the reflector, in Java to provide this function the package to call Java.Lang.The reflect reflection mechanism is extremely formidable.&l

52、t;/p><p>　　1) when run analysis class ability.</p><p>　　2) when run searches observes a class of object.</p><p>　　3) realizes the general array operation code.</p><p>　　4)

53、 provides the method object.</p><p>　　But this mechanism mainly aims at the tool but not the application and the procedure.</p><p>　　In the reflection mechanism most important part is that permi

54、ts class that you inspect structure. With to API includes:</p><p>　　Java.Lang.Reflect.Field returns to the field.</p><p>　　Java.Reflect.Method returns to the method.</p><p>　　Java

55、.Lang.Reflect.Constructor returns to the parameter.</p><p>　　Method pointer: Java does not have the method pointer, makes a method address another method, may invoke it in behind, but the interface is the b

56、etter solution.</p><p>　　23. interface: should showing class could do what but not to assign how to do, a class may realize one or many interfaces.</p><p>　　24.The interface is not a class, but

57、 is to conforms to a interface request class of set of standard.</p><p>　　If realizes a interface to need 2 steps:</p><p>　　1) the statement class needs to realize assigns the interface.</p&g

58、t;<p>　　2) provides in the interface all methods definition.</p><p>　　Stated a class realizes a interface to need to use the implements key words</p><p>　　Class actionB implements Compara

59、ble its actionb needs to provide the CompareTo method, the interface is not the class, cannot use a new example interface.</p><p>　　25.A class only then a super class, but a class can realize many interfaces

60、. In a Java important interface: Cloneable</p><p>　　26.The interface and call-back :to programs a commonly used pattern is call-back,in the pattern, you may refer when this class of pattern settled specific

61、time occurs returns to adjusts on the object the method.</p><p>　　Example:ActionListener interface monitor.</p><p>　　Similar API includes:</p><p>　　Java.Swing.JOptionPane</p>

62、<p>　　Java.Swing.Timer</p><p>　　Java.Awt.Tookit</p><p>　　27.Object clone:The clone method is a object protection method, this meant your code cannot simple invoke it.</p><p>　

63、　28.Inner class an inner class definition is the definition in another class.</p><p>　　The reason is:</p><p>　　1) an inner class object can visit founds its object realization, including private

64、 data.</p><p>　　2) about other classes in the same package in that, inner class can be hided.</p><p>　　3) the anonymous inner class may the very convenient definition accent.</p><p>

65、;　　In 4) uses the category to be possible the extremely convenient compilation event driver.</p><p>　　29.Agent class (proxy):</p><p>　　1) appointing all codes that interfaces request</p>

66、<p>　　2) all methods (toString equals) that object class define</p><p>　　30.Data type:Java is kind of emphasizing type language, each variable all must be declared its types at first, in java altogether

67、 has 8 basic types . four kinds are the long, two kinds are the float, one is the char, being used in the Unicode code char, Boolean. </p><p>　　1. java is simple </p><p>　　Java and C + + are ver

68、y similar, but much simpler. All the high-level programming language features, is not absolutely necessary have been deleted. For example, Java does not overload operator, the title of the document, pre-processing, com

69、puting pointer, the structure of the joint, multi-dimensional array, templates and implicit type conversion. If you know a little C, C + + or Pascal, you will soon master Java. Here is a simple procedure JavaHelloWorld

70、: </p><p>　　publicclassHelloInternet ( </p><p>　　publicstaticvoidmain (Stringargv []) ( </p><p>　　System. out. println ( "HelloIn-ternet!") </p><p><b>

71、;　　) </b></p><p><b>　　) </b></p><p>　　2. Java is object-oriented </p><p>　　Java is an object-oriented programming language. In addition to the simple types, such

72、 as digital and Boolean operators in addition, Java is an object of most. As with any object-oriented languages, Java code also organized by category. Each category provides a definition of the object behavior. Anothe

73、r type of succession can be a kind of behavior. In the category of the root level, often the target category. Java support for the single type of inherited hierarchy. This means that each ca</p><p>　　3.

74、Java is a type of static </p><p>　　In a Java program, it is essential to the definition used by the target (number of characters, such as an array) type. This will help programmers quickly found because the

75、 procedure when the compiler can detect the type of error. However, Java System objects are also dynamic types. A requirement for the type of dynamic is often possible, so programmers can write the procedures for diffe

76、rent types of objects to do different things. </p><p>　　4. Is a Java-based compiler </p><p>　　When running Java programs, which were first compiled into byte code. Byte code is very similar to

77、 the machine instructions, so Java program is very efficient. However, the byte code does not specifically for a particular machine, so no need to recompile Java program can be in many different computer implementation.

78、 Java source code files were compiled into a category, which is equivalent to process byte code performance. In a Java class file, and an example for all of the variables are in t</p><p>　　5. Java is arch

79、itecture neutral </p><p>　　Java language is the same for each computer. For example, simple types are the same: 32-bit integer always, always 64-bit long integers. It is strange, such as C and C + + progra

80、mming language, and so fashionable it is not the case. As a result of these languages so the definition of freedom, each of the compiler and development environment will be different, so that this process nuisance becom

81、e a transplant. Java programs can easily gain access to transplants, and there is no need to re-com</p><p>　　6. Java is a sound </p><p>　　Java program can not be caused by the collapse of the

82、computer. Java careful testing of the system memory of each visit, make sure it is legitimate and will not cause any problems. However, even if the Java program may also be wrong. If there is some kind of unexpected t

83、hings, the process will not collapse, and to abandon the exception. Procedures for such an exception would be found to address them. Traditional computer programs can access the full memory. May (unconsciously) to ame

84、nd any</p><p>　　7. Java is a compact </p><p>　　As the Java is designed to run on a small computer, as a programming language for the system is relatively small. It effectively in more than 4MB

85、 of RAM to run on PC machine. Java translator occupied by only a few hundred KB. This translator for the Java platform independence and portability is reliable. Due to Java is very small, it is a very small computer m

86、emory, such as the Java-based PC, as well as television sets, ovens, telephone and home computer, and so on, it is ideal. </p><p>　　8. Java is a multi-threaded </p><p>　　Java program can run mo

87、re than one thread. For example, it can be a thread in a time-consuming to complete the calculation, and other users to interact with the threads of dialogue. Therefore, users do not have to stop working, waiting for t

88、he Java computing time-consuming process. In the multi-threaded programming environment, it is often difficult because many things may occur at the same time. However, Java provides easy-to-use features simultaneously,

89、 so that the programming easier. </p><p><b>　　中文翻譯</b></p><p><b>　　JAVA介紹</b></p><p>　　作者：Martin Ngobye.</p><p>　　出處：Computing Static Slice for

90、 Java Programs</p><p>　　Java是被設(shè)計(jì)用來解決在上下文分布式的異構(gòu)網(wǎng)絡(luò)中應(yīng)用程序開發(fā)的問題。在這些復(fù)雜問題中，首要的是安全發(fā)布應(yīng)用程序、消耗最小的系統(tǒng)資源、可以在任何硬件和軟件平臺(tái)上運(yùn)行以及被動(dòng)態(tài)地?cái)U(kuò)展。</p><p>　　Java最初是作為研發(fā)方案的一部分而開發(fā)的，這個(gè)研究方案是為了給廣闊多樣的網(wǎng)絡(luò)設(shè)備和嵌入式系統(tǒng)開發(fā)高級(jí)的軟件。目標(biāo)是開發(fā)一個(gè)小巧的、可靠性

91、高的、可移植的、分布式的、實(shí)時(shí)的操作系統(tǒng)平臺(tái)。當(dāng)這個(gè)方案開始的時(shí)候，C++是精選的語言，但是過了一段時(shí)間，用C++語言遇到的困難也隨之增長，解決這些問題最好的辦法是創(chuàng)造一個(gè)全新的語言平臺(tái)。設(shè)計(jì)和體系結(jié)構(gòu)的決定汲取了多種語言，例如Eiffel、 SmallTalk,、Objective C以及 Cedar/Mesa。結(jié)果證明這個(gè)語言平臺(tái)是理想的，對(duì)于開發(fā)一個(gè)可靠性高的、可移植的、分布式的、基于終端用戶網(wǎng)絡(luò)的應(yīng)用程序在多種環(huán)境中廣泛搜索從嵌

92、入網(wǎng)絡(luò)的設(shè)備到萬維網(wǎng)和桌上型電腦。</p><p>　　Java的需求設(shè)計(jì)通過自然狀態(tài)的，在軟件必須被配置的處理環(huán)境中被推動(dòng)的。</p><p>　　因特網(wǎng)和萬維網(wǎng)的巨大發(fā)展導(dǎo)致我們完全地以新的情形著眼于開發(fā)和發(fā)行軟件。對(duì)于全球電子化的商業(yè)和銷售發(fā)行的存在，Java必須使安全的，高性能的和非常健壯的應(yīng)用程序在多平臺(tái)異構(gòu)的，分布式的網(wǎng)絡(luò)中開發(fā)。</p><p>　　在

93、異構(gòu)的網(wǎng)絡(luò)中，多平臺(tái)上運(yùn)行會(huì)使傳統(tǒng)配置的二進(jìn)制發(fā)送、釋放、更新、補(bǔ)丁等等無效。為了在這些問題中幸存下來，Java必須是體系結(jié)構(gòu)中立的、可移植的以及可以被動(dòng)態(tài)的修改。</p><p>　　為滿足以上的需求而開發(fā)的Java系統(tǒng)是簡單的，所以它能夠被絕大多數(shù)的程序員進(jìn)行編程；熟悉的，所以當(dāng)前的程序員學(xué)習(xí)Java語言是簡單的；面向?qū)ο蟮模瑸榱死矛F(xiàn)代的軟件開發(fā)方法學(xué)和適合分布式的客戶機(jī)/服務(wù)器應(yīng)用程序；多線程的，為了高性

94、能在應(yīng)用程序中需要執(zhí)行多個(gè)并發(fā)的活動(dòng),例如多媒體；解釋的，為了最大極限的可移植和動(dòng)態(tài)的容量。</p><p>　　同時(shí)，以上的需求完全是由收集的時(shí)髦詞語組成的，所以在開始以前讓我們來查看它們中的一些和它們的各自的優(yōu)點(diǎn)。</p><p>　　什么是完全新的，樣式風(fēng)格在Java語言和它的運(yùn)行系統(tǒng)結(jié)合它們來產(chǎn)生一個(gè)靈通的且強(qiáng)大的編程系統(tǒng)。 </p><p>　　在軟件中，

95、用Java語言開發(fā)的你的應(yīng)用程序可以在多種機(jī)器總體結(jié)構(gòu)、操作系統(tǒng)和圖形用戶接口之間移植。運(yùn)用Java語言，諸如軟件開發(fā)者的工作就會(huì)變得簡單的多——你會(huì)把你的全部精力都集中在最終的目標(biāo)：準(zhǔn)時(shí)運(yùn)送革新的產(chǎn)品、基于可靠的構(gòu)造的Java語言。較好的開發(fā)軟件的方法在這里，現(xiàn)在，Java語言平臺(tái)會(huì)帶給你這些。</p><p>　　許多動(dòng)態(tài)的語言像Lisp、TCL和 SmallTalk通常被應(yīng)用于原型構(gòu)造技術(shù)它們成功原因中的

96、一個(gè)在于它們非常健壯——你沒有必要去擔(dān)心關(guān)于解除或破壞存儲(chǔ)器。</p><p>　　同樣的，程序員可以相對(duì)大膽的處理存儲(chǔ)器，當(dāng)在Java語言里面編程的時(shí)候。垃圾回收系統(tǒng)使程序員的工作大為容易，卸下了程序員肩上存儲(chǔ)管理之負(fù)擔(dān)，存儲(chǔ)分配錯(cuò)誤不再發(fā)生。</p><p>　　一般認(rèn)為像Lisp, TCL, 和 SmallTalk這樣一些語言十分適合于原型法的另一個(gè)理由，是因?yàn)樗鼈儾灰竽闶茉缙跊Q定

97、的約束——這些語言的語義是很豐富的。</p><p>　　Java語言有著嚴(yán)密的對(duì)應(yīng)的屬性：它促使你做出清楚的選擇。伴隨著這些選擇帶來了許多的協(xié)助——你可以寫一個(gè)方法調(diào)用，而且如果你在編寫時(shí)有一些錯(cuò)誤的時(shí)候，在編譯的時(shí)候?qū)?huì)被告知。你沒有必要去擔(dān)心關(guān)于方法調(diào)用的錯(cuò)誤。</p><p>　　Java初學(xué)者需掌握的30個(gè)基本概念</p><p><b>　　基

98、本概念：</b></p><p>　　1.OOP中唯一關(guān)系是什么是對(duì)象的接口，就像計(jì)算機(jī)的銷售商不管電源內(nèi)部結(jié)構(gòu)是怎樣的，它只關(guān)心能否給你提供電，也就是只要知道能或不能而不是知道怎樣和為什么會(huì)有電。所有的程序是由一定的屬性和行為對(duì)象組成的，不同的對(duì)象的訪問通過函數(shù)調(diào)用來完成，對(duì)象間所有的交流都是通過方法調(diào)用，通過封裝對(duì)象數(shù)據(jù)，很大限度上提高復(fù)用率。</p><p>　　2.OO

99、P中最重要的思想是類，類是模板是藍(lán)圖，從類中構(gòu)造一個(gè)對(duì)象，即創(chuàng)建了這個(gè)類的一個(gè)實(shí)例(instance)。</p><p>　　3.封裝：就是把數(shù)據(jù)和行為結(jié)合起在一個(gè)包中，并對(duì)對(duì)象使用者隱藏?cái)?shù)據(jù)的實(shí)現(xiàn)過程，一個(gè)對(duì)象中的數(shù)據(jù)叫他的實(shí)例字段(instance field)。</p><p>　　4.通過擴(kuò)展一個(gè)類來獲得一個(gè)新類叫繼承(inheritance)，而所有的類都是由Object根超類擴(kuò)

100、展而得，根超類下文會(huì)做介紹。</p><p>　　5.對(duì)象的3個(gè)主要特性：</p><p>　　Behavior——說明這個(gè)對(duì)象能做什么。</p><p>　　Tate——當(dāng)對(duì)象施加方法時(shí)對(duì)象的反映。</p><p>　　Dentity——與其他相似行為對(duì)象的區(qū)分標(biāo)志。</p><p>　　每個(gè)對(duì)象有唯一的indent

101、ity 而這3者之間相互影響。</p><p><b>　　6.類之間的關(guān)系：</b></p><p>　　use-a ：依賴關(guān)系</p><p>　　has-a ：聚合關(guān)系</p><p>　　is-a ：繼承關(guān)系——例:A類繼承了B類，此時(shí)A類不僅有了B類的方法，還有其自己的方法(個(gè)性存在于共性中)。</p&g

102、t;<p>　　7.構(gòu)造對(duì)象使用構(gòu)造器:構(gòu)造器的提出，構(gòu)造器是一種特殊的方法，構(gòu)造對(duì)象并對(duì)其初始化。</p><p>　　例:Data類的構(gòu)造器叫Data。</p><p>　　New Data()——構(gòu)造一個(gè)新對(duì)象，且初始化當(dāng)前時(shí)間。</p><p>　　Data happyday=new Data()——把一個(gè)對(duì)象賦值給一個(gè)變量happyday，從