【正文】 too restrictive.) Each of these approaches is a good solution to the particular class of problem they’re designed to solve, but when you step outside of that domain they bee awkward. 我們應該把對機器建模替換為對對我們所要處理的問題進行建模。你必須去設法了解深澀的語言本身以便于去編寫你自己的對象庫。 JSP 引擎只需在 Servlet 代碼最后被修改后編譯一次，然后這個編譯過的 Servlet 就可以被執(zhí)行了。 JavaBeans 和 ActiveX 被 “快速應用程序開發(fā) ”(RAD)工具發(fā)行商推廣給Java 和 Windows 應用程序開發(fā)者用來快速開發(fā)復雜的程序。 當然，也可以利用 Java Servlet 來控制網(wǎng)站的邏輯，通過Java Servlet 調(diào)用 JSP 文件的方式來將網(wǎng)站的邏輯和內(nèi)容分離。在討論過程中 ,研討會的主席提出了 Jini 的議題 ,這在當時是一項新的 Java 技術(shù) 。依據(jù)開發(fā)團隊的大小，及項目的復雜程度，可以對靜態(tài) HTML 和動態(tài)內(nèi)容進行弱分離（ weaker separation）和強分離（ stronger separation）。 JSP 與 Microsoft的 ASP 技術(shù)非常相似。JSP The Java Server Pages( JSP) is a kind of according to web of the script plait distance technique, similar carries the script language of Java in the server of the Netscape pany of server side JavaScript( SSJS) and the Active Server Pages(ASP) of the Microsoft. JSP pares the SSJS and ASP to have better can expand sex, and it is no more exclusive than any factory or some one particular server of Web. Though the norm of JSP is to be draw up by the Sun pany of, any factory can carry out the JSP on own system. The After Sun release the JSP( the Java Server Pages) formally, the this kind of new Web application development technique very quickly caused the people39。按照 Sun的說法， JSP 能夠適應市場上包括 Apache WebServer、 在內(nèi)的 85%的服務器產(chǎn)品。 Java 程序員可以致力于動態(tài)代碼。為了解決 Java Servlet 的這種缺點， SUN 推出了 JSP。 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， 當與一個 JavaBeans 類結(jié)合在一起時， JSP 提供了一種使內(nèi)容和顯示邏輯分開的簡單方式。 HTML 和圖形設計師把它們的設計的實施工作交給了 Web 編寫者，使他們不得不加倍工作 —— 常常是手工編寫，因為沒有合適的工具可以把服務器端腳本與 HTML 內(nèi)容結(jié)合起來。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 自動把它們編譯成 Java 字節(jié)碼。用對象的方式來思考問題相比于過程化的思考問題 方式有著很大的差別，而且設計一個對象比起設計一個過程來說是一個很大的挑戰(zhàn)，特別是當你要設計一個可復用的對象（ reusable objects）的時候。這些語言是在匯編語言之上的一個大的提升，但是它們的主要抽象依據(jù)仍然是匯編語言，我們?nèi)匀灰诳紤]如何用程序解決問題的同時考慮程序在計算機結(jié)構(gòu)上的實現(xiàn)。這種程度的表示形式基本上足夠程序員不受約束的處理各種特殊類型的問題。 The Chapter will introduce many of ideas of Java and Objectoriented programming on a conceptual level, but keep in mind that you’re not expected to be able to write fullfledged Java Programs after reading this chapter. All the detailed descriptions and examples will follow throughout the course of this book. 這一章將會在概念層面上引導你去接觸很多 Java 和面向?qū)ο蟪绦蛟O計思想，但是不要指望通過閱讀這一章就寫出一個完整的 java 程序。 I:關(guān)于對象的介紹 Why has objectoriented programming had such a sweeping impact on the software development muity? 為什么面向?qū)ο笳Z言有如此廣泛的影響力之于軟件開發(fā)社區(qū)？ Objectoriented programming appeals at multiple levels. For managers, it promises faster and cheaper development and maintenance. For analysts and designers, the modeling process bees simpler and produces a clear, manageable design. For programmers, the elegance and clarity of the object model and the power of objectoriented tools and libraries makes programming a much more pleasant task, and programmers experience an increase in productivity. Everybody wins, it would seem. If there’s a downside, it is the expense of the learning curve. Thinking in objects is a dramatic departure from thinking procedurally, and the process of designing objects is much more challenging than procedural design, especially if you’re trying to create reusable objects. In the past, a novice practitioner of objectoriented programming was faced with a choice between two daunting tasks: 1. Choose a language such as Smalltalk in which you had to learn a large library before being productive. 2. Choose C++ with virtually no libraries at all,1 and struggle through the depths of the language in order to write your own libraries of objects. 面向?qū)ο蟪绦蛟O計吸引著多個層面。 現(xiàn)在來看看 JSP 是如何處理 HTTP 請求的。 SSJS 和 ASP 都是在幾年前推出的，那時網(wǎng)絡還很年輕，沒有人知道除了把所有的商務、數(shù)據(jù)和表達邏輯統(tǒng)統(tǒng)堆進原始網(wǎng)頁中之外還有什么更好的解決方法。實際上 ,JSP 不只采用了這種通用概念 ,它甚至使用許多和 ASP 相同的特殊標簽。 Java Servlet 是 JSP 技術(shù)的基礎，而且大型的 Web 應用程序的開發(fā)需要 Java Servlet和 JSP配合才能完成， Servlet 這個名稱源于 Applet，現(xiàn)在國內(nèi)的翻譯方式很多，本 書為了避免誤會，決定直接采用 Servlet 而不做任何翻譯，讀者如果愿意，可以稱之為“小服務程序”。畢竟，在特定平臺上能夠用 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。 hand over with each other, and the manifestation result in dynamic state bornly, mixing with the HTML page of the static state HTML code. The Beans can be JavaBeans or module of EJBs. Moreover, the more plicated claim model can see make from is request other JSP pages of the page call sign or Java Servlets. The engine of JSP wants to chase the code of Java that the label of JSP, code of Java in the JSP page even all converts into the big piece together with the static state HTML contents actually. These codes piece was anized the Java Servlet that customer can not see to go to by the engine of JSP, then the Servlet edits and translate them automatically byte code of Java. Thus, the visitant that is the website requests a JSP page, under the condition of it is not knowing, an already born, the Servlet actual full general that prepared to edit and translate pletes all works, very concealment but again and efficiently. The Servlet is to edit and translate of, so the code of JSP in the web page does not need when the every time requests that page is explain. The engine of JSP need to be edit and translate after Servlet the code end is modify only once, then this Servlet that editted and translate can be carry out. The in view of the fact JSP engine auto is born to edit and translate the Servlet also, need not procedure member begins to edit and translate the code, so the JSP can bring vivid sex that function and fast developments need that you are efficiently. Compared with the traditional CGI, the JSP has the equal advantage. First, on the speed, the traditional procedure of CGI needs to use the standard importation of the system to output the equipments to carry out the dynamic state web page born, but the JSP is direct is mutually the connection with server. And say for the CGI, each interview needs to add to add a progress to handle, the progress build up and destroy by burning cons