jsp外文翻譯

1、<p><b>　　JSP簡(jiǎn)介</b></p><p>　　JSP(JavaServer Pages)是由Sun Microsystems公司倡導(dǎo)、許多公司參與一起建立的一種動(dòng)態(tài)網(wǎng)頁技術(shù)標(biāo)準(zhǔn)。JSP技術(shù)有點(diǎn)類似ASP技術(shù)，它是在傳統(tǒng)的網(wǎng)頁HTML文件(*.htm,*.html)中插入Java程序段(Scriptlet)和JSP標(biāo)記(tag)，從而形成JSP文件(*.jsp)。 &l

2、t;/p><p>　　用JSP開發(fā)的Web應(yīng)用是跨平臺(tái)的，即能在Linux下運(yùn)行，也能在其他操作系統(tǒng)上運(yùn)行。</p><p>　　JSP技術(shù)使用Java編程語言編寫類XML的tags和scriptlets，來封裝產(chǎn)生動(dòng)態(tài)網(wǎng)頁的處理邏輯。網(wǎng)頁還能通過tags和scriptlets訪問存在于服務(wù)端的資源的應(yīng)用邏輯。JSP將網(wǎng)頁邏輯與網(wǎng)頁設(shè)計(jì)和顯示分離，支持可重用的基于組件的設(shè)計(jì)，使基于Web的應(yīng)用

3、程序的開發(fā)變得迅速和容易。 </p><p>　　Web服務(wù)器在遇到訪問JSP網(wǎng)頁的請(qǐng)求時(shí)，首先執(zhí)行其中的程序段，然后將執(zhí)行結(jié)果連同JSP文件中的HTML代碼一起返回給客戶。插入的Java程序段可以操作數(shù)據(jù)庫(kù)、重新定向網(wǎng)頁等，以實(shí)現(xiàn)建立動(dòng)態(tài)網(wǎng)頁所需要的功能。 </p><p>　　JSP與Java Servlet一樣，是在服務(wù)器端執(zhí)行的，通常返回該客戶端的就是一個(gè)HTML文本，因此客戶端只

4、要有瀏覽器就能瀏覽。 </p><p>　　JSP的1.0規(guī)范的最后版本是1999年9月推出的，12月又推出了1.1規(guī)范。目前較新的是JSP1.2規(guī)范，JSP2.0規(guī)范的征求意見稿也已出臺(tái)。</p><p>　　JSP頁面由HTML代碼和嵌入其中的Java代碼所組成。服務(wù)器在頁面被客戶端請(qǐng)求以后對(duì)這些Java代碼進(jìn)行處理，然后將生成的HTML頁面返回給客戶端的瀏覽器。Java Servle

5、t 是JSP的技術(shù)基礎(chǔ)，而且大型的Web應(yīng)用程序的開發(fā)需要Java Servlet和JSP配合才能完成。JSP具備了Java技術(shù)的簡(jiǎn)單易用，完全的面向?qū)ο?，具有平臺(tái)無關(guān)性且安全可靠，主要面向因特網(wǎng)的所有特點(diǎn)。 </p><p><b>　　JSP技術(shù)的強(qiáng)勢(shì)</b></p><p>　?。?）一次編寫，到處運(yùn)行。在這一點(diǎn)上Java比PHP更出色，除了系統(tǒng)之外，代碼不用做

6、任何更改。</p><p>　?。?）系統(tǒng)的多平臺(tái)支持?；旧峡梢栽谒衅脚_(tái)上的任意環(huán)境中開發(fā)，在任意環(huán)境中進(jìn)行系統(tǒng)部署，在任意環(huán)境中擴(kuò)展。相比ASP/PHP的局限性是顯而易見的。 </p><p>　　（3）強(qiáng)大的可伸縮性。從只有一個(gè)小的Jar文件就可以運(yùn)行Servlet/JSP，到由多臺(tái)服務(wù)器進(jìn)行集群和負(fù)載均衡，到多臺(tái)Application進(jìn)行事務(wù)處理，消息處理，一臺(tái)服務(wù)器到無數(shù)臺(tái)服務(wù)

7、器，Java顯示了一個(gè)巨大的生命力。 </p><p>　?。?）多樣化和功能強(qiáng)大的開發(fā)工具支持。這一點(diǎn)與ASP很像，Java已經(jīng)有了許多非常優(yōu)秀的開發(fā)工具，而且許多可以免費(fèi)得到，并且其中許多已經(jīng)可以順利的運(yùn)行于多種平臺(tái)之下。 </p><p><b>　　JSP技術(shù)的弱勢(shì)</b></p><p>　?。?） 與ASP一樣，Java的一些優(yōu)勢(shì)正

8、是它致命的問題所在。正是由于為了跨平臺(tái)的功能，為了極度的伸縮能力，所以極大的增加了產(chǎn)品的復(fù)雜性。 </p><p>　?。?） Java的運(yùn)行速度是用class常駐內(nèi)存來完成的，所以它在一些情況下所使用的內(nèi)存比起用戶數(shù)量來說確實(shí)是“最低性能價(jià)格比”了。從另一方面，它還需要硬盤空間來儲(chǔ)存一系列的.java文件和.class文件，以及對(duì)應(yīng)的版本文件。</p><p>　　JSP六種內(nèi)置對(duì)象：&

9、lt;/p><p>　　request, response, out, session, application, config, pagecontext, page, exception. </p><p>　　一.request對(duì)象：</p><p>　　該對(duì)象封裝了用戶提交的信息，通過調(diào)用該對(duì)象相應(yīng)的方法可以獲取封裝的信息，即使用該對(duì)象可以獲取用戶提交信息。&l

10、t;/p><p>　　二.response對(duì)象：</p><p>　　對(duì)客戶的請(qǐng)求做出動(dòng)態(tài)的響應(yīng)，向客戶端發(fā)送數(shù)據(jù)。</p><p>　　三．session對(duì)象</p><p>　　1.什么是session：session對(duì)象是一個(gè)JSP內(nèi)置對(duì)象，它在第一個(gè)JSP頁面被裝載時(shí)自動(dòng)創(chuàng)建，完成會(huì)話期管理。</p><p>　　

11、從一個(gè)客戶打開瀏覽器并連接到服務(wù)器開始，到客戶關(guān)閉瀏覽器離開這個(gè)服務(wù)器結(jié)束，被稱為一個(gè)會(huì)話。當(dāng)一個(gè)客戶訪問一個(gè)服務(wù)器時(shí)，可能會(huì)在這個(gè)服務(wù)器的幾個(gè)頁面之間反復(fù)連接，反復(fù)刷新一個(gè)頁面，服務(wù)器應(yīng)當(dāng)通過某種辦法知道這是同一個(gè)客戶，這就需要session對(duì)象。</p><p>　　2．session對(duì)象的ID：當(dāng)一個(gè)客戶首次訪問服務(wù)器上的一個(gè)JSP頁面時(shí)，JSP引擎產(chǎn)生一個(gè)session對(duì)象，同時(shí)分配一個(gè)String類型的

12、ID號(hào)，JSP引擎同時(shí)將這個(gè)ID號(hào)發(fā)送到客戶端，存放在Cookie中，這樣session對(duì)象和客戶之間就建立了一一對(duì)應(yīng)的關(guān)系。當(dāng)客戶再訪問連接該服務(wù)器的其他頁面時(shí)，不再分配給客戶新的session對(duì)象，直到客戶關(guān)閉瀏覽器后，服務(wù)器端該客戶的session對(duì)象才取消，并且和客戶的會(huì)話對(duì)應(yīng)關(guān)系消失。當(dāng)客戶重新打開瀏覽器再連接到該服務(wù)器時(shí)，服務(wù)器為該客戶再創(chuàng)建一個(gè)新的session對(duì)象。</p><p>　　四．a(chǎn)pl

13、ication對(duì)象</p><p>　　1．什么是application:</p><p>　　服務(wù)器啟動(dòng)后就產(chǎn)生了這個(gè)application對(duì)象，當(dāng)客戶再所訪問的網(wǎng)站的各個(gè)頁面之間瀏覽時(shí)，這個(gè)application對(duì)象都是同一個(gè)，直到服務(wù)器關(guān)閉。但是與session不同的是，所有客戶的application對(duì)象都是同一個(gè)，即所有客戶共享這個(gè)內(nèi)置的application對(duì)象。</p&

14、gt;<p>　　2．a(chǎn)pplication對(duì)象常用方法:</p><p>　　(1)public void setAttribute(String key,Object obj): 將參數(shù)Object指定的對(duì)象obj添加到application對(duì)象中，并為添加的對(duì)象指定一個(gè)索引關(guān)鍵字。</p><p>　　(2)public Object getAttribute(Stri

15、ng key): 獲取application對(duì)象中含有關(guān)鍵字的對(duì)象。</p><p><b>　　五．out對(duì)象</b></p><p>　　out對(duì)象是一個(gè)輸出流，用來向客戶端輸出數(shù)據(jù)。out對(duì)象用于各種數(shù)據(jù)的輸出。</p><p><b>　　六．Cookie</b></p><p>　　1.什

16、么是Cookie：</p><p>　　Cookie是Web服務(wù)器保存在用戶硬盤上的一段文本。Cookie允許一個(gè)Web站點(diǎn)在用戶的電腦上保存信息并且隨后再取回它。</p><p>　　舉例來說，一個(gè)Web站點(diǎn)可能會(huì)為每一個(gè)訪問者產(chǎn)生一個(gè)唯一的ID，然后以Cookie文件的形式保存在每個(gè)用戶的機(jī)器上。 </p><p>　　如果您使用IE瀏覽器訪問Web，您會(huì)看到所

17、有保存在您的硬盤上的Cookie。它們最常存放的地方是：c:\windows\cookies(在Window2000中則是C:\Documents and Settings\您的用戶名\Cookies )</p><p>　　Cookie是以“關(guān)鍵字key=值value“的格式來保存紀(jì)錄的.</p><p>　　2．創(chuàng)建一個(gè)Cookie對(duì)象，調(diào)用Cookie對(duì)象的構(gòu)造函數(shù)可以創(chuàng)建Cooki

18、e。Cookie對(duì)象的構(gòu)造函數(shù)有兩個(gè)字符串參數(shù)：Cookie名字和Cookie值。</p><p>　　Cookie c=new Cookie(“username”,”john”);</p><p>　　3． JSP中如果要將封裝好的Cookie對(duì)象傳送到客戶端，使用response的addCookie()方法。</p><p>　　格式：response.addC

19、ookie(c)</p><p>　　4．讀取保存到客戶端的Cookie,使用request對(duì)象的getCookies()方法，執(zhí)行時(shí)將所有客戶端傳來的Cookie對(duì)象以數(shù)組的形式排列，如果要取出符合需要的Cookie對(duì)象，就需要循環(huán)比較數(shù)組內(nèi)每個(gè)對(duì)象的關(guān)鍵字。 </p><p><b>　　JSP </b></p><p>　　Open C

20、ategory: WEB, JAVA, dynamic pages, the Knowledge Network </p><p><b>　　Contents </b></p><p>　　? JSP Profile </p><p>　　? JSP technology strength </p><p>　　? J

21、SP technology vulnerable </p><p>　　? JSP six built-in objects: </p><p>　　? JSP dynamic web site development and technology </p><p>　　JSP Profile </p><p>　　JSP (JavaServ

22、er Pages) is initiated by Sun Microsystems, Inc., with many companies to participate in the establishment of a dynamic web page technical standards. JSP technology somewhat similar to ASP technology, it is in the traditi

23、onal HTML web page document (*. htm, *. html) to insert the Java programming paragraph (Scriptlet) and JSP tag (tag), thus JSP documents (*. jsp). </p><p>　　Using JSP development of the Web application is cr

24、oss-platform that can run on Linux, is also available for other operating systems. </p><p>　　JSP technology to use the Java programming language prepared by the category of XML tags and scriptlets, to produc

25、e dynamic pages package processing logic. Page also visit by tags and scriptlets exist in the services side of the resources of logic. JSP page logic and web page design and display separation, support reusable component

26、-based design, Web-based application development is rapid and easy. </p><p>　　Web server in the face of visits JSP page request, the first implementation of the procedures of, and then together with the resu

27、lts of the implementation of JSP documents in HTML code with the return to the customer. Insert the Java programming operation of the database can be re-oriented websites, in order to achieve the establishment of dynamic

28、 pages needed to function. </p><p>　　JSP and Java Servlet, is in the implementation of the server, usually returned to the client is an HTML text, as long as the client browser will be able to visit. </p&

29、gt;<p>　　JSP 1.0 specification of the final version is launched in September 1999, December has introduced 1.1 specifications. At present relatively new is JSP1.2 norms, JSP2.0 norms of the draft has also been int

30、roduced. </p><p>　　JSP pages from HTML code and Java code embedded in one of the components. The server was in the pages of client requests after the Java code and then will generate the HTML pages to return

31、 to the client browser. Java Servlet JSP is the technical foundation and large-scale Web application development needs of Java Servlet and JSP support to complete. JSP with the Java technology easy to use, fully object-o

32、riented, and a platform-independent and secure, mainly for all the characteristics of the In</p><p>　　JSP technology strength </p><p>　　(1) time to prepare, run everywhere. At this point Java be

33、tter than PHP, in addition to systems, the code not to make any changes. </p><p>　　(2) the multi-platform support. Basically on all platforms of any development environment, in any environment for deployment

34、 in any environment in the expansion. Compared ASP / PHP limitations are obvious. </p><p>　　(3) a strong scalability. From only a small Jar documents can run Servlet / JSP, to the multiple servers clustering

35、 and load balancing, to multiple Application for transaction processing, information processing, a server to numerous servers, Java shows a tremendous Vitality. </p><p>　　(4) diversification and powerful dev

36、elopment tools support. This is similar to the ASP, Java already have many very good development tools, and many can be free, and many of them have been able to run on a variety of platforms under. </p><p>　

37、　JSP technology vulnerable </p><p>　　(1) and the same ASP, Java is the advantage of some of its fatal problem. It is precisely because in order to cross-platform functionality, in order to extreme stretching

38、 capacity, greatly increasing the complexity of the product. </p><p>　　(2) Java's speed is class to complete the permanent memory, so in some cases by the use of memory compared to the number of users is

39、 indeed a "minimum cost performance." On the other hand, it also needs disk space to store a series of. Java documents and. Class, as well as the corresponding versions of documents. </p><p>　　JSP

40、six built-in objects: </p><p>　　request, response, out, session, application, config, pagecontext, page, exception. </p><p>　　1. Request for: </p><p>　　The object of the package of

41、information submitted by users, by calling the object corresponding way to access the information package, namely the use of the target users can access the information. </p><p>　　2. Response object: </p&

42、gt;<p>　　The customer's request dynamic response to the client sent the data. </p><p>　　三. session object </p><p>　　1. What is the session: session object is a built-in objects JSP, i

43、t in the first JSP pages loaded automatically create, complete the conversation of management. </p><p>　　From a customer to open a browser and connect to the server, to close the browser, leaving the end of

44、this server, known as a conversation. When a customer visits a server, the server may be a few pages link between repeatedly, repeatedly refresh a page, the server should be through some kind of way to know this is the s

45、ame client, which requires session object. </p><p>　　2. session object ID: When a customer's first visit to a server on the JSP pages, JSP engines produce a session object, and assigned a String type of

46、ID number, JSP engine at the same time, the ID number sent to the client, stored in Cookie, this session objects, and customers on the establishment of a one-to-one relationship. When a customer to connect to the server

47、of the other pages, customers no longer allocated to the new session object, until, close your browser, the client-server object t</p><p>　　四. aplication target </p><p>　　1. What is the applicat

48、ion: </p><p>　　Servers have launched after the application object, when a customer to visit the site between the various pages here, this application objects are the same, until the server is down. But with

49、the session difference is that all customers of the application objects are the same, that is, all customers share this built-in application objects. </p><p>　　2. application objects commonly used methods: &

50、lt;/p><p>　　(1) public void setAttribute (String key, Object obj): Object specified parameters will be the object obj added to the application object, and to add the subject of the designation of a keyword inde

51、x. </p><p>　　(2) public Object getAttribute (String key): access to application objects containing keywords for. </p><p>　　五. out targets </p><p>　　out as a target output flow, used

52、 to client output data. out targets for the output data. </p><p>　　六. Cookie </p><p>　　1. What is Cookie: </p><p>　　Cookie is stored in Web server on the user's hard drive secti

53、on of the text. Cookie allow a Web site on the user's computer to store information on and then get back to it. </p><p>　　For example, a Web site may be generated for each visitor a unique ID, and then t

54、o Cookie in the form of documents stored in each user's machine. </p><p>　　If you use IE browser to visit Web, you will see all stored on your hard drive on the Cookie. They are most often stored in plac

55、es: c: \ windows \ cookies (in Window2000 is in the C: \ Documents and Settings \ your user name \ Cookies) </p><p>　　Cookie is "keyword key = value value" to preserve the format of the record. <

56、;/p><p>　　2. Targets the creation of a Cookie, Cookie object called the constructor can create a Cookie. Cookie object constructor has two string parameters: Cookie Cookie name and value. </p><p>　

57、　Cookie c = new Cookie ( "username", "john"); </p><p>　　3. If the JSP in the package good Cookie object to send to the client, the use of the response addCookie () method. </p><

58、;p>　　Format: response.addCookie (c) </p><p>　　4. Save to read the client's Cookie, the use of the object request getCookies () method will be implemented in all client came to an array of Cookie objec

59、ts in the form of order, to meet the need to remove the Cookie object, it is necessary to compare an array cycle Each target keywords.</p><p><b>　　JSP簡(jiǎn)介</b></p><p>　　JSP(JavaServer P

60、ages)是由Sun Microsystems公司倡導(dǎo)、許多公司參與一起建立的一種動(dòng)態(tài)網(wǎng)頁技術(shù)標(biāo)準(zhǔn)。JSP技術(shù)有點(diǎn)類似ASP技術(shù)，它是在傳統(tǒng)的網(wǎng)頁HTML文件(*.htm,*.html)中插入Java程序段(Scriptlet)和JSP標(biāo)記(tag)，從而形成JSP文件(*.jsp)。 </p><p>　　用JSP開發(fā)的Web應(yīng)用是跨平臺(tái)的，即能在Linux下運(yùn)行，也能在其他操作系統(tǒng)上運(yùn)行。</p>

61、<p>　　JSP技術(shù)使用Java編程語言編寫類XML的tags和scriptlets，來封裝產(chǎn)生動(dòng)態(tài)網(wǎng)頁的處理邏輯。網(wǎng)頁還能通過tags和scriptlets訪問存在于服務(wù)端的資源的應(yīng)用邏輯。JSP將網(wǎng)頁邏輯與網(wǎng)頁設(shè)計(jì)和顯示分離，支持可重用的基于組件的設(shè)計(jì)，使基于Web的應(yīng)用程序的開發(fā)變得迅速和容易。 </p><p>　　Web服務(wù)器在遇到訪問JSP網(wǎng)頁的請(qǐng)求時(shí)，首先執(zhí)行其中的程序段，然后將執(zhí)行

62、結(jié)果連同JSP文件中的HTML代碼一起返回給客戶。插入的Java程序段可以操作數(shù)據(jù)庫(kù)、重新定向網(wǎng)頁等，以實(shí)現(xiàn)建立動(dòng)態(tài)網(wǎng)頁所需要的功能。 </p><p>　　JSP與Java Servlet一樣，是在服務(wù)器端執(zhí)行的，通常返回該客戶端的就是一個(gè)HTML文本，因此客戶端只要有瀏覽器就能瀏覽。 </p><p>　　JSP的1.0規(guī)范的最后版本是1999年9月推出的，12月又推出了1.1規(guī)范。目

63、前較新的是JSP1.2規(guī)范，JSP2.0規(guī)范的征求意見稿也已出臺(tái)。</p><p>　　JSP頁面由HTML代碼和嵌入其中的Java代碼所組成。服務(wù)器在頁面被客戶端請(qǐng)求以后對(duì)這些Java代碼進(jìn)行處理，然后將生成的HTML頁面返回給客戶端的瀏覽器。Java Servlet 是JSP的技術(shù)基礎(chǔ)，而且大型的Web應(yīng)用程序的開發(fā)需要Java Servlet和JSP配合才能完成。JSP具備了Java技術(shù)的簡(jiǎn)單易用，完全的面

64、向?qū)ο?，具有平臺(tái)無關(guān)性且安全可靠，主要面向因特網(wǎng)的所有特點(diǎn)。 </p><p><b>　　JSP技術(shù)的強(qiáng)勢(shì)</b></p><p>　　（1）一次編寫，到處運(yùn)行。在這一點(diǎn)上Java比PHP更出色，除了系統(tǒng)之外，代碼不用做任何更改。</p><p>　　（2）系統(tǒng)的多平臺(tái)支持。基本上可以在所有平臺(tái)上的任意環(huán)境中開發(fā)，在任意環(huán)境中進(jìn)行系統(tǒng)部署，在

65、任意環(huán)境中擴(kuò)展。相比ASP/PHP的局限性是顯而易見的。 </p><p>　　（3）強(qiáng)大的可伸縮性。從只有一個(gè)小的Jar文件就可以運(yùn)行Servlet/JSP，到由多臺(tái)服務(wù)器進(jìn)行集群和負(fù)載均衡，到多臺(tái)Application進(jìn)行事務(wù)處理，消息處理，一臺(tái)服務(wù)器到無數(shù)臺(tái)服務(wù)器，Java顯示了一個(gè)巨大的生命力。 </p><p>　　（4）多樣化和功能強(qiáng)大的開發(fā)工具支持。這一點(diǎn)與ASP很像，Jav

66、a已經(jīng)有了許多非常優(yōu)秀的開發(fā)工具，而且許多可以免費(fèi)得到，并且其中許多已經(jīng)可以順利的運(yùn)行于多種平臺(tái)之下。 </p><p><b>　　JSP技術(shù)的弱勢(shì)</b></p><p>　　（1） 與ASP一樣，Java的一些優(yōu)勢(shì)正是它致命的問題所在。正是由于為了跨平臺(tái)的功能，為了極度的伸縮能力，所以極大的增加了產(chǎn)品的復(fù)雜性。 </p><p>　　（2

67、） Java的運(yùn)行速度是用class常駐內(nèi)存來完成的，所以它在一些情況下所使用的內(nèi)存比起用戶數(shù)量來說確實(shí)是“最低性能價(jià)格比”了。從另一方面，它還需要硬盤空間來儲(chǔ)存一系列的.java文件和.class文件，以及對(duì)應(yīng)的版本文件。</p><p>　　JSP六種內(nèi)置對(duì)象：</p><p>　　request, response, out, session, application, config

68、, pagecontext, page, exception. </p><p>　　一.request對(duì)象：</p><p>　　該對(duì)象封裝了用戶提交的信息，通過調(diào)用該對(duì)象相應(yīng)的方法可以獲取封裝的信息，即使用該對(duì)象可以獲取用戶提交信息。</p><p>　　二.response對(duì)象：</p><p>　　對(duì)客戶的請(qǐng)求做出動(dòng)態(tài)的響應(yīng)，向客戶

69、端發(fā)送數(shù)據(jù)。</p><p>　　三．session對(duì)象</p><p>　　1.什么是session：session對(duì)象是一個(gè)JSP內(nèi)置對(duì)象，它在第一個(gè)JSP頁面被裝載時(shí)自動(dòng)創(chuàng)建，完成會(huì)話期管理。</p><p>　　從一個(gè)客戶打開瀏覽器并連接到服務(wù)器開始，到客戶關(guān)閉瀏覽器離開這個(gè)服務(wù)器結(jié)束，被稱為一個(gè)會(huì)話。當(dāng)一個(gè)客戶訪問一個(gè)服務(wù)器時(shí)，可能會(huì)在這個(gè)服務(wù)器的幾個(gè)頁面

70、之間反復(fù)連接，反復(fù)刷新一個(gè)頁面，服務(wù)器應(yīng)當(dāng)通過某種辦法知道這是同一個(gè)客戶，這就需要session對(duì)象。</p><p>　　2．session對(duì)象的ID：當(dāng)一個(gè)客戶首次訪問服務(wù)器上的一個(gè)JSP頁面時(shí)，JSP引擎產(chǎn)生一個(gè)session對(duì)象，同時(shí)分配一個(gè)String類型的ID號(hào)，JSP引擎同時(shí)將這個(gè)ID號(hào)發(fā)送到客戶端，存放在Cookie中，這樣session對(duì)象和客戶之間就建立了一一對(duì)應(yīng)的關(guān)系。當(dāng)客戶再訪問連接該服務(wù)

71、器的其他頁面時(shí)，不再分配給客戶新的session對(duì)象，直到客戶關(guān)閉瀏覽器后，服務(wù)器端該客戶的session對(duì)象才取消，并且和客戶的會(huì)話對(duì)應(yīng)關(guān)系消失。當(dāng)客戶重新打開瀏覽器再連接到該服務(wù)器時(shí)，服務(wù)器為該客戶再創(chuàng)建一個(gè)新的session對(duì)象。</p><p>　　四．a(chǎn)plication對(duì)象</p><p>　　1．什么是application:</p><p>　　服務(wù)

72、器啟動(dòng)后就產(chǎn)生了這個(gè)application對(duì)象，當(dāng)客戶再所訪問的網(wǎng)站的各個(gè)頁面之間瀏覽時(shí)，這個(gè)application對(duì)象都是同一個(gè)，直到服務(wù)器關(guān)閉。但是與session不同的是，所有客戶的application對(duì)象都是同一個(gè)，即所有客戶共享這個(gè)內(nèi)置的application對(duì)象。</p><p>　　2．a(chǎn)pplication對(duì)象常用方法:</p><p>　　(1)public void

73、setAttribute(String key,Object obj): 將參數(shù)Object指定的對(duì)象obj添加到application對(duì)象中，并為添加的對(duì)象指定一個(gè)索引關(guān)鍵字。</p><p>　　(2)public Object getAttribute(String key): 獲取application對(duì)象中含有關(guān)鍵字的對(duì)象。</p><p><b>　　五．out對(duì)象&

74、lt;/b></p><p>　　out對(duì)象是一個(gè)輸出流，用來向客戶端輸出數(shù)據(jù)。out對(duì)象用于各種數(shù)據(jù)的輸出。</p><p><b>　　六．Cookie</b></p><p>　　1.什么是Cookie：</p><p>　　Cookie是Web服務(wù)器保存在用戶硬盤上的一段文本。Cookie允許一個(gè)Web站點(diǎn)

75、在用戶的電腦上保存信息并且隨后再取回它。</p><p>　　舉例來說，一個(gè)Web站點(diǎn)可能會(huì)為每一個(gè)訪問者產(chǎn)生一個(gè)唯一的ID，然后以Cookie文件的形式保存在每個(gè)用戶的機(jī)器上。 </p><p>　　如果您使用IE瀏覽器訪問Web，您會(huì)看到所有保存在您的硬盤上的Cookie。它們最常存放的地方是：c:\windows\cookies(在Window2000中則是C:\Documents

76、and Settings\您的用戶名\Cookies )</p><p>　　Cookie是以“關(guān)鍵字key=值value“的格式來保存紀(jì)錄的.</p><p>　　2．創(chuàng)建一個(gè)Cookie對(duì)象，調(diào)用Cookie對(duì)象的構(gòu)造函數(shù)可以創(chuàng)建Cookie。Cookie對(duì)象的構(gòu)造函數(shù)有兩個(gè)字符串參數(shù)：Cookie名字和Cookie值。</p><p>　　Cookie c=n

77、ew Cookie(“username”,”john”);</p><p>　　3． JSP中如果要將封裝好的Cookie對(duì)象傳送到客戶端，使用response的addCookie()方法。</p><p>　　格式：response.addCookie(c)</p><p>　　4．讀取保存到客戶端的Cookie,使用request對(duì)象的getCookies()方

78、法，執(zhí)行時(shí)將所有客戶端傳來的Cookie對(duì)象以數(shù)組的形式排列，如果要取出符合需要的Cookie對(duì)象，就需要循環(huán)比較數(shù)組內(nèi)每個(gè)對(duì)象的關(guān)鍵字。 </p><p><b>　　JSP </b></p><p>　　Open Category: WEB, JAVA, dynamic pages, the Knowledge Network </p><p

79、><b>　　Contents </b></p><p>　　? JSP Profile </p><p>　　? JSP technology strength </p><p>　　? JSP technology vulnerable </p><p>　　? JSP six built-in objects

80、: </p><p>　　? JSP dynamic web site development and technology </p><p>　　JSP Profile </p><p>　　JSP (JavaServer Pages) is initiated by Sun Microsystems, Inc., with many companies to p

81、articipate in the establishment of a dynamic web page technical standards. JSP technology somewhat similar to ASP technology, it is in the traditional HTML web page document (*. htm, *. html) to insert the Java programmi

82、ng paragraph (Scriptlet) and JSP tag (tag), thus JSP documents (*. jsp). </p><p>　　Using JSP development of the Web application is cross-platform that can run on Linux, is also available for other operating

83、systems. </p><p>　　JSP technology to use the Java programming language prepared by the category of XML tags and scriptlets, to produce dynamic pages package processing logic. Page also visit by tags and scri

84、ptlets exist in the services side of the resources of logic. JSP page logic and web page design and display separation, support reusable component-based design, Web-based application development is rapid and easy. </p

85、><p>　　Web server in the face of visits JSP page request, the first implementation of the procedures of, and then together with the results of the implementation of JSP documents in HTML code with the return to

86、 the customer. Insert the Java programming operation of the database can be re-oriented websites, in order to achieve the establishment of dynamic pages needed to function. </p><p>　　JSP and Java Servlet, is

87、 in the implementation of the server, usually returned to the client is an HTML text, as long as the client browser will be able to visit. </p><p>　　JSP 1.0 specification of the final version is launched in

88、September 1999, December has introduced 1.1 specifications. At present relatively new is JSP1.2 norms, JSP2.0 norms of the draft has also been introduced. </p><p>　　JSP pages from HTML code and Java code emb

89、edded in one of the components. The server was in the pages of client requests after the Java code and then will generate the HTML pages to return to the client browser. Java Servlet JSP is the technical foundation and l

90、arge-scale Web application development needs of Java Servlet and JSP support to complete. JSP with the Java technology easy to use, fully object-oriented, and a platform-independent and secure, mainly for all the charact

91、eristics of the In</p><p>　　JSP technology strength </p><p>　　(1) time to prepare, run everywhere. At this point Java better than PHP, in addition to systems, the code not to make any changes. &

92、lt;/p><p>　　(2) the multi-platform support. Basically on all platforms of any development environment, in any environment for deployment in any environment in the expansion. Compared ASP / PHP limitations are o

93、bvious. </p><p>　　(3) a strong scalability. From only a small Jar documents can run Servlet / JSP, to the multiple servers clustering and load balancing, to multiple Application for transaction processing, i

94、nformation processing, a server to numerous servers, Java shows a tremendous Vitality. </p><p>　　(4) diversification and powerful development tools support. This is similar to the ASP, Java already have many

95、 very good development tools, and many can be free, and many of them have been able to run on a variety of platforms under. </p><p>　　JSP technology vulnerable </p><p>　　(1) and the same ASP, Ja

96、va is the advantage of some of its fatal problem. It is precisely because in order to cross-platform functionality, in order to extreme stretching capacity, greatly increasing the complexity of the product. </p>&

97、lt;p>　　(2) Java's speed is class to complete the permanent memory, so in some cases by the use of memory compared to the number of users is indeed a "minimum cost performance." On the other hand, it also

98、 needs disk space to store a series of. Java documents and. Class, as well as the corresponding versions of documents. </p><p>　　JSP six built-in objects: </p><p>　　request, response, out, sessi

99、on, application, config, pagecontext, page, exception. </p><p>　　1. Request for: </p><p>　　The object of the package of information submitted by users, by calling the object corresponding way to

100、 access the information package, namely the use of the target users can access the information. </p><p>　　2. Response object: </p><p>　　The customer's request dynamic response to the client

101、sent the data. </p><p>　　三. session object </p><p>　　1. What is the session: session object is a built-in objects JSP, it in the first JSP pages loaded automatically create, complete the convers

102、ation of management. </p><p>　　From a customer to open a browser and connect to the server, to close the browser, leaving the end of this server, known as a conversation. When a customer visits a server, the

103、 server may be a few pages link between repeatedly, repeatedly refresh a page, the server should be through some kind of way to know this is the same client, which requires session object. </p><p>　　2. sessi

104、on object ID: When a customer's first visit to a server on the JSP pages, JSP engines produce a session object, and assigned a String type of ID number, JSP engine at the same time, the ID number sent to the client,

105、stored in Cookie, this session objects, and customers on the establishment of a one-to-one relationship. When a customer to connect to the server of the other pages, customers no longer allocated to the new session objec