Overview of JSP Technology
Benefits of JSP
JSP pages are translated into servlets. So, fundamentally, any task JSP pages can perform could also be accomplished by servlets. However, this underlying equivalence does not mean that servlets and JSP pages are equally appropriate in all scenarios. The issue is not the power of the technology, it is the convenience, productivity, and maintainability of one or the other. After all, anything you can do on a particular computer platform in the Java programming language you could also do in assembly language. But it still matters which you choose.
JSP provides the following benefits over servlets alone:
• It is easier to write and maintain the HTML. Your static code is ordinary HTML: no extra backslashes, no double quotes, and no lurking Java syntax.
• You can use standard Web-site development tools. Even HTML tools that know nothing about JSP can be used because they simply ignore the JSP tags.
• You can divide up your development team. The Java programmers can work on the dynamic code. The Web developers can concentrate on the presentation layer. On large projects, this division is very important. Depending on the size of your team and the complexity of your project, you can enforce a weaker or stronger separation between the static HTML and the dynamic content.
Now, this discussion is not to say that you should stop using servlets and use only JSP instead. By no means. Almost all projects will use both. For some requests in your project, you will use servlets. For others, you will use JSP. For still others, you will combine them with the MVC architecture . You want the appropriate tool for the job, and servlets, by themselves, do not complete your toolkit.



JSP技術(shù)概述
一、JSP的好處
JSP頁(yè)面最終會(huì)轉(zhuǎn)換成servler。因而，從根本上，JSP頁(yè)面能夠執(zhí)行的任何任務(wù)都可以用servler來完成。然而，這種底層的等同性并不意味著servler和JSP頁(yè)面對(duì)于所有的情況都等同適用。問題不在于技術(shù)的能力，而是二者在便利性、生產(chǎn)率和可維護(hù)性上的不同。畢竟，在特定平臺(tái)上能夠用Java編程語言完成的事情，同樣可以用匯編語言來完成，但是選擇哪種語言依舊十分重要。
和單獨(dú)使用servler相比，JSP提供下述好處：
 JSP中HTML的編寫與維護(hù)更為簡(jiǎn)單。JSP中可以使用常規(guī)的HTML：沒有額外的反斜杠，沒有額外的雙引號(hào)，也沒有暗含的Java語法。
 能夠使用標(biāo)準(zhǔn)的網(wǎng)站開發(fā)工具。即使對(duì)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）。
 可以對(duì)開發(fā)團(tuán)隊(duì)進(jìn)行劃分。Java程序員可以致力于動(dòng)態(tài)代碼。Web開發(fā)人員可以將經(jīng)理集中在表示層（presentation layer）上。對(duì)于大型的項(xiàng)目，這種劃分極為重要。依據(jù)開發(fā)團(tuán)隊(duì)的大小，及項(xiàng)目的復(fù)雜程度，可以對(duì)靜態(tài)HTML和動(dòng)態(tài)內(nèi)容進(jìn)行弱分離（weaker separation）和強(qiáng)分離（stronger separation）。
在此，這個(gè)討論并不是讓您停止使用servlets，只使用JSP。幾乎所有的項(xiàng)目都會(huì)同時(shí)用到這兩種技術(shù)。針對(duì)項(xiàng)目中的某些請(qǐng)求，您可能會(huì)在MVC構(gòu)架下組合使用這兩項(xiàng)技術(shù)。我們總是希望用適當(dāng)?shù)墓ぞ咄瓿上鄬?duì)應(yīng)的工作，僅僅是servlet并不能填滿您的工具箱。
二、JSP相對(duì)于競(jìng)爭(zhēng)技術(shù)的優(yōu)勢(shì)
許多年前，Marty受到邀請(qǐng),參加一個(gè)有關(guān)軟件技術(shù)的小型(20個(gè)人)研討會(huì).做在Marty旁邊的人是James Gosling--- Java編程語言的發(fā)明者。隔幾個(gè)位置,是來自華盛頓一家大型軟件公司的高級(jí)經(jīng)理。在討論過程中,研討會(huì)的主席提出了Jini的議題,這在當(dāng)時(shí)是一項(xiàng)新的Java技術(shù).主席向該經(jīng)理詢問他的想法.他繼續(xù)說,他們會(huì)持續(xù)關(guān)注這項(xiàng)技術(shù),如果這項(xiàng)技術(shù)變得流行起來,他們會(huì)遵循公司的“接受并擴(kuò)充(embrace and extend)”的策略.此時(shí), Gosling隨意地插話說“你的意思其實(shí)就是不接受且不擴(kuò)充(disgrace and distend)。”