【正文】 而且對于CGI來說,每一個(gè)訪問就需要新增加一個(gè)進(jìn)程來處理,進(jìn)程不斷地建立和銷毀對于作為Web服務(wù)器的計(jì)算機(jī)將是不小的負(fù)擔(dān)。JSP引擎實(shí)際上要把JSP標(biāo)簽、JSP頁中的Java代碼甚至連同靜態(tài)HTML內(nèi)容都轉(zhuǎn)換為大塊的Java代碼。由于JSP的以組件為中心的性質(zhì),它可以被Java和非Java開發(fā)者同樣使用。其實(shí)在企業(yè)中,可重用組件的應(yīng)用早已經(jīng)很成熟,沒有人愿意為它們的應(yīng)用程序重寫那些邏輯。實(shí)際上,有一些JSP引擎就是采用的其他腳本語言,如EMACScript、WebL 等,但實(shí)際上這幾種腳本語言也是構(gòu)建在Java上面,編譯為Servlet來實(shí)現(xiàn)的。然而,作為一種腳本語言,JSP又顯得過于強(qiáng)大了,在JSP中幾乎可以使用全部的Java類。Java社團(tuán)沒有發(fā)明這一思想將頁面設(shè)計(jì)成由靜態(tài)HTML 和用特殊標(biāo)簽標(biāo)記的動(dòng)態(tài)代碼混合組成.。得益于Java 的跨平臺的特性,Servlet也是平臺無關(guān)的,實(shí)際上,只要符合Java Servlet規(guī)范,Servlet是完全與平臺無關(guān)且是與Web 服務(wù)器無關(guān)的。幾乎所有的項(xiàng)目都會同時(shí)用到這兩種技術(shù)。能夠使用標(biāo)準(zhǔn)的網(wǎng)站開發(fā)工具。下面我們簡單的對它進(jìn)行介紹。盡管JSP 規(guī)范是由Sun公司制定的,但任何廠商都可以在自己的系統(tǒng)上實(shí)現(xiàn)JSP。s concern. JSP provided a special development environment for the Web application that establishes the high dynamic state. According to the Sun parlance, the JSP can adapt to include the Apache WebServer, on the market at inside of 85% server product. This chapter will introduce the related knowledge of JSP and Databases, and JavaBean related contents, is all certainly rougher introduction among them basic contents, say perhaps to is a Guide only, if the reader needs the more detailed information, pleasing the book of consult the homologous JSP.A. Generalize The JSP(Java Server Pages) is from the pany of Sun Microsystems initiate, the many panies the participate to the build up the together of the a kind the of dynamic the state web the page technique standard, the it have the it in the construction the of the dynamic state the web page the strong but the do not the especially of the function. JSP and the technique of ASP of the Microsoft is very alike. Both all provide the ability that mixes with a certain procedure code and is explain by the language engine to carry out the procedure code in the code of HTML. Underneath we are simple of carry on the introduction to it.JSP pages are translated into servlets . So, fundamentally, any task JSP pages can perform could also be acplished 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 puter platform in the Java programming language you could also do in assembly language. But it still matters which you 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 Website 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 plexity 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 bine them with the MVC architecture . You want the appropriate tool for the job, and servlets, by themselves, do not plete your toolkit.B. Source of JSPThe technique of JSP of the pany of Sun, making the page of Web develop the personnel can use the HTML perhaps marking of XML to design to turn the end page with format. Use the perhaps small script future life of marking of JSP bees the dynamic state on the page contents.( the contents changes according to the claim of) The Java Servlet is a technical foundation of JSP, and the large Web applies the development of the procedure to need the Java Servlet to match with the JSP and then can plete, this name of Servlet es from the Applet, the local translation method of now is a lot of, this book in order not to misconstruction, decide the direct adoption Servlet but don39。s machine/server the realm. JavaBeans and ActiveX were published the pany to expand to apply the procedure developer for Java and Windows to use to e to develop the plicated procedure quickly by the fast application procedur