【正文】 和格式化最終頁面。為了解決Java Servlet的這種缺點(diǎn)，SUN推出了JSP。ColdFusion多年前就已經(jīng)這樣做了。作為一種基于文本的、以顯示為中心的開發(fā)技術(shù)，JSP提供了Java Servlet的所有好處，并且，當(dāng)與一個(gè)JavaBeans類結(jié)合在一起時(shí)，JSP提供了一種使內(nèi)容和顯示邏輯分開的簡單方式。按照J(rèn)SP規(guī)范書寫，和Java沒有任何關(guān)系的Scriptlet也是可以的，不過，由于JSP的強(qiáng)大功能主要在于能和JavaBeans、Enterprise JavaBeans共同運(yùn)轉(zhuǎn)，所以即使是Scriptlet部分不使用Java，編譯成的執(zhí)行代碼也應(yīng)該是與Java相關(guān)的。HTML和圖形設(shè)計(jì)師把它們的設(shè)計(jì)的實(shí)施工作交給了Web編寫者，使他們不得不加倍工作—— 常常是手工編寫，因?yàn)闆]有合適的工具可以把服務(wù)器端腳本與HTML內(nèi)容結(jié)合起來。非Java開發(fā)者可以通過JSP的標(biāo)簽(Tags)來使用高級(jí)Java開發(fā)者創(chuàng)建的JavaBeans。這些代碼塊被JSP引擎組織到用戶看不到的Java Servlet中去，然后Servlet自動(dòng)把它們編譯成Java字節(jié)碼。其次，JSP是專門為Web開發(fā)而設(shè)計(jì)的，其目的是為了建立基于Web的應(yīng)用程序，其中包含了一整套的規(guī)范和工具。能干的人，不在情緒上計(jì)較，只在做事上認(rèn)真；無能的人！不在做事上認(rèn)真，只在情緒上計(jì)較。首先，在速度上，傳統(tǒng)的CGI程序需要使用系統(tǒng)的標(biāo)準(zhǔn)輸入輸出設(shè)備來實(shí)現(xiàn)動(dòng)態(tài)網(wǎng)頁的生成，而JSP是直接和服務(wù)器相關(guān)聯(lián)的。另外，更加復(fù)雜的請(qǐng)求模型可看作從被請(qǐng)求頁呼叫其他JSP頁或Java Servlets。它以JavaBeans和Enterprise JavaBeans(EJB)組件包含商務(wù)和數(shù)據(jù)邏輯的模型為基礎(chǔ)，提供大量標(biāo)簽和一個(gè)腳本平臺(tái)用來在HTML頁中顯示由JavaBeans產(chǎn)生或回送的內(nèi)容。表達(dá)邏輯通常和商務(wù)及數(shù)據(jù)邏輯混在一起，這使得當(dāng)程序員試圖改變一個(gè)應(yīng)用程序的外觀而不想破壞與之緊密結(jié)合的商務(wù)邏輯時(shí)，應(yīng)用程序的維護(hù)就變得十分艱難。在JSP規(guī)范書中，并沒有明確要求JSP中的程序代碼部分(稱為Scriptlet)一定要用Java來寫。 JSP的特點(diǎn)按照腳本語言是服務(wù)于某一個(gè)子系統(tǒng)的語言這種論述，JSP應(yīng)當(dāng)被看作是一種腳本語言。”在此, Gosling的抱怨顯示出，他感到這個(gè)公司會(huì)從其他公司那里拿走技術(shù),，形勢已經(jīng)完全不同。由于Java Servlet內(nèi)部是以線程方式提供服務(wù)，不必對(duì)于每個(gè)請(qǐng)求都啟動(dòng)一個(gè)進(jìn)程，并且利用多線程機(jī)制可以同時(shí)為多個(gè)請(qǐng)求服務(wù)，因此Java Servlet效率非常高。在某些項(xiàng)目中，更適宜選用servlet，而針對(duì)項(xiàng)目中的某些請(qǐng)求，我們可能會(huì)在MVC構(gòu)架下組合使用這兩項(xiàng)技術(shù)。即使是那些對(duì)JSP一無所知的HTML工具，我們也可以使用，因?yàn)樗鼈儠?huì)忽略JSP標(biāo)簽（JSP tags）。JSP頁面最終會(huì)轉(zhuǎn)換成servlet。 在Sun正式發(fā)布JSP(Java Server Pages)之后，這種新的Web應(yīng)用開發(fā)技術(shù)很快引起了人們的關(guān)注。s usual embrace and extend strategy. At this point, Gosling lightheartedly interjected You mean disgrace and distend. Now, the grievance that Gosling was airing was that he felt that this pany would take technology from other panies and suborn it for their own purposes. But guess what? The shoe is on the other foot here. The Java munity did not invent the idea of designing pages as a mixture of static HTML and dynamic code marked with special tags. For example, Cold Fusion did it years earlier. Even ASP (a product from the very software pany of the aforementioned manager) popularized this approach before JSP came along and decided to jump on the bandwagon. In fact, JSP not only adopted the general idea, it even used many of the same special tags as ASP did.The JSP is an establishment at the model of Java servlets on of the expression layer technique, it makes the plait write the HTML to bee more like the SSJS, it also allows you carry the static state HTML contents and servers the script mix to put together the born dynamic state exportation. JSP the script language that the Java is the tacit approval, however, be like the ASP and can use other languages( such as JavaScript and VBScript), the norm of JSP also allows to use other languages. CHARACTERISTICSIs a service according to the script language in some one language of the statures system this kind of discuss, the JSP should be see make is a kind of script language. However, be a kind of script language, the JSP seemed to be too strong again, almost can use all Javas in the JSP.Be a kind of according to text originally of, take manifestation as the central development technique, the JSP provided all advantages of the Java Servlet, and, when bine with a JavaBeans together, providing a kind of make contents and manifestation that simple way that logic separate. Separate the contents and advantage of logical manifestations is, the personnel who renews the page external appearance need not know the code of Java, and renew the JavaBeans personnel also need not be design the web page of expert in hand, can use to take the page of JavaBeans JSP to define the template of Web, to build up a from have the alike external appearance of the website that page constitute. JavaBeans pletes the data to provide, having no code of Java in the template thus, this means that these templates can be written the personnel by a HTML plait to support. Certainly, can also make use of the Java Servlet to control the logic of the website, adjust through the Java Servlet to use the way of the document of JSP to separate website of logic and contents.Generally speaking, in actual engine of JSP, the page of JSP is the edit and translate type while carry out, not explain the type of. Explain the dynamic state web page development tool of the type, such as ASP, PHP3 etc., because speed etc. reason, have already can39。t do any translation, if reader would like to, can call it as small service procedure. The Servlet is similar to traditional CGI, ISAPI, NSAPI etc. Web procedure development the function of the tool in fact, at use the