外文翻譯---jsp簡(jiǎn)介

1、<p><b>　　附錄1</b></p><p>　　JSP Profile</p><p>　　JSP (JavaServer Pages) is initiated by Sun Microsystems, Inc., with many companies to participate in the establishment of a dynami

2、c 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 programming paragraph (Scriptlet) and JSP tag (tag),

3、 thus JSP documents (*. jsp). Using JSP development of the Web application is cross-platform that can run on Linux, is also available for other operat</p><p>　　Web server in the face of visits JSP page reque

4、st, 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 the customer. Insert the Java programming operation of the data

5、base can be re-oriented websites, in order to achieve the establishment of dynamic pages needed to function. </p><p>　　JSP and Java Servlet, is in the implementation of the server, usually returned to the cl

6、ient is an HTML text, as long as the client browser will be able to visit. JSP 1.0 specification of the final version is launched in September 1999, December has introduced 1.1 specifications. At present relatively new i

7、s JSP1.2 norms, JSP2.0 norms of the draft has also been introduced. </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 th

8、e Java code and then will generate the HTML pages to return 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 complet

9、e. JSP with the Java technology easy to use, fully object-oriented, and a platform-independent and secure, mainly for all the characteristics of the In</p><p>　　JSP technology strength </p><p>　

10、　(1) time to prepare, run everywhere. At this point Java better 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

11、 development environment, in any environment for deployment in any environment in the expansion. Compared ASP / PHP limitations are obvious. </p><p>　　(3) a strong scalability. From only a small Jar document

12、s can run Servlet / JSP, to the multiple servers clustering and load balancing, to multiple Application for transaction processing, information processing, a server to numerous servers, Java shows a tremendous Vitality.

13、</p><p>　　(4) diversification and powerful development tools support. This is similar to </p><p>　　the ASP, Java already have many very good development tools, and many can be free, and many of

14、them have been able to run on a variety of platforms under. </p><p>　　JSP technology vulnerable </p><p>　　(1) and the same ASP, Java is the advantage of some of its fatal problem. It is precisel

15、y because in order to cross-platform functionality, in order to extreme stretching capacity, greatly increasing the complexity of the product. </p><p>　　(2) Java's speed is class to complete the permanen

16、t 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 needs disk space to store a series of. Java documents and. Clas

17、s, as well as the corresponding versions of documents. </p><p>　　JSP six built-in objects: </p><p>　　request, response, out, session, application, config, pagecontext, page, exception. </p>

18、;<p>　　1. Request for: </p><p>　　The object of the package of information submitted by users, by calling the object corresponding way to access the information package, namely the use of the target us

19、ers can access the information. </p><p>　　2. Response object: </p><p>　　The customer's request dynamic response to the client sent the data. </p><p>　　3. session object </p&g

20、t;<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 conversation of management. </p><p>　　From a customer to o

21、pen 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 server may be a few pages link between repeatedly, repeatedly r

22、efresh 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. session object ID: When a customer's first visit to a server on t

23、he 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, stored in Cookie, this session objects, and customers on the est

24、ablishment 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 object, until, close your browser, the client-server object t</p&g

25、t;<p>　　4. aplication target </p><p>　　1. What is the application: </p><p>　　Servers have launched after the application object, when a customer to visit the site between the various page

26、s here, this application objects are the same, until the server is down. But with the session difference is that all customers of the application objects are the same, that is, all customers share this built-in applicati

27、on objects. </p><p>　　2. application objects commonly used methods: </p><p>　　(1) public void setAttribute (String key, Object obj): Object specified parameters will be the object obj added to t

28、he application object, and to add the subject of the designation of a keyword index. </p><p>　　(2) public Object getAttribute (String key): access to application objects containing keywords for. </p>

29、<p>　　5. out targets </p><p>　　out as a target output flow, used to client output data. out targets for the output data. </p><p>　　6. Cookie </p><p>　　1. What is Cookie: Cookie

30、 is stored in Web server on the user's hard drive section of the text. Cookie allow a Web site on the user's computer to store information on and then get back to it. For example, a Web site may be generated for

31、each visitor a unique ID, and then to Cookie in the form of documents stored in each user's machine. If you use IE browser to visit Web, you will see all stored on your hard drive on the Cookie. They are most often s

32、tored in places: c: \ windows \ cookies (in Win</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: Co

33、okie Cookie name and value. 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

34、 () method. </p><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

35、to an array of Cookie objects 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>

36、<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(yè)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(yè)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)。 用JSP開(kāi)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。 JSP技術(shù)

37、使用Java編程語(yǔ)言編寫(xiě)類XML的tags和scriptlets，來(lái)封裝產(chǎn)生動(dòng)態(tài)網(wǎng)頁(yè)的處理邏輯。網(wǎng)頁(yè)還能通過(guò)tags和scriptlets訪問(wèn)存在于服務(wù)端的資源的應(yīng)用邏輯。JSP將網(wǎng)頁(yè)邏輯與網(wǎng)頁(yè)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(kāi)發(fā)變得迅速和容易。 </p><p>　　Web服務(wù)器在遇到訪問(wèn)JSP網(wǎng)頁(yè)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

38、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(yè)等，以實(shí)現(xiàn)建立動(dòng)態(tài)網(wǎng)頁(yè)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。 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(jiàn)稿也已出臺(tái)。 </p&

39、gt;<p>　　JSP頁(yè)面由HTML代碼和嵌入其中的Java代碼所組成。服務(wù)器在頁(yè)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(yè)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(kāi)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(wú)關(guān)性且安全可靠，主要面向因特網(wǎng)的所有特點(diǎn)。 </p>

40、;<p><b>　　JSP技術(shù)的強(qiáng)勢(shì) </b></p><p>　?。?）一次編寫(xiě)，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>　?。?）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(kāi)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(jiàn)的。 </p>

41、;<p>　?。?）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(wú)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(kāi)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(kāi)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

42、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)正是它致命的問(wèn)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(lái)完成的，所以它在一些情況下所

43、使用的內(nèi)存比起用戶數(shù)量來(lái)說(shuō)確實(shí)是“最低性能價(jià)格比”了。從另一方面，它還需要硬盤(pán)空間來(lái)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, pagecontext, page, exception. <

44、;/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(guò)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)，向客戶端發(fā)送數(shù)據(jù)。 </p><p>　　三．s

45、ession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(yè)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(kāi)瀏覽器并連接到服務(wù)器開(kāi)始，到客戶關(guān)閉瀏覽器離開(kāi)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(wèn)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(yè)面之間反復(fù)連接，反復(fù)刷新一個(gè)頁(yè)面，服務(wù)器應(yīng)當(dāng)通過(guò)某種辦法知道這

46、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(wèn)服務(wù)器上的一個(gè)JSP頁(yè)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(wèn)連接該服務(wù)器的其他頁(yè)面時(shí)，不再分配給客戶新的session對(duì)象，直到

47、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(kāi)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)器啟動(dòng)后就產(chǎn)生了這個(gè)application對(duì)象，當(dāng)客

48、戶再所訪問(wèn)的網(wǎng)站的各個(gè)頁(yè)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 setAttribute(String key,

49、Object obj): 將參數(shù)Object指定的對(duì)象obj添加到</p><p>　　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

50、 </b></p><p>　　out對(duì)象是一個(gè)輸出流，用來(lái)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： Cookie是Web服務(wù)器保存在用戶硬盤(pán)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

51、它。 舉例來(lái)說(shuō)，一個(gè)Web站點(diǎn)可能會(huì)為每一個(gè)訪問(wèn)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。 如果您使用IE瀏覽器訪問(wèn)Web，您會(huì)看到所有保存在您的硬盤(pán)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 ) Cookie是以“關(guān)鍵字key=值value“的格式來(lái)保存紀(jì)錄的.

52、</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。 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