計(jì)算機(jī)畢業(yè)設(shè)計(jì) 譯文

1、下一代網(wǎng)絡(luò)技術(shù)在以前，互聯(lián)網(wǎng)只是一堆靜態(tài)的網(wǎng)頁。而今天互聯(lián)網(wǎng)與我們的生活聯(lián)系很充 分，這要?dú)w功于所謂的Web 2.0技術(shù)集的使用?，F(xiàn)在這種技術(shù)已經(jīng)很受歡迎了， 甚至連企業(yè)都很想用它們。在本文中，我們來探討這些技術(shù)，以及它們?nèi)绾文芗?勵(lì)下一代企業(yè)門戶的發(fā)展。另外，我們來設(shè)想一下Web 2.0技術(shù)的未來前景。要了解和欣賞下一代網(wǎng)絡(luò)技術(shù)，重要的是要了解上個(gè)技術(shù)年代提供的技術(shù)基 礎(chǔ)。長期以來，網(wǎng)站只不過是一個(gè)由一堆網(wǎng)頁形成用來給大家一起點(diǎn)擊和瀏覽。 雖然經(jīng)過事實(shí)證明這是了不起的信息來源，但是也有很多限制。舉個(gè)例說：人們 不能相互影響，這只是一次在一個(gè)頁面上的瀏覽經(jīng)歷。如果兩個(gè)人在同一個(gè)網(wǎng)站 瀏覽，它們

2、也沒有辦法知道對(duì)方的存在。如果你想修改網(wǎng)頁或其中的一部分，那 么你必須熟悉HTML編碼。而且你必須修改已經(jīng)完成的網(wǎng)頁。有沒有辦法只拿出 它的一部分出來修改呢。在以前的一段時(shí)間里，網(wǎng)站就想雨后春筍般的出現(xiàn)和成 長。局勢(shì)變成如果要變得消息聯(lián)通，那么它必須要擁有一個(gè)網(wǎng)站。有這么多的網(wǎng) 站由一堆靜態(tài)的頁面組成，我們?cè)诨ヂ?lián)網(wǎng)上的生活變的相當(dāng)乏味。所以我們要打 破這種單調(diào)的網(wǎng)上生活。關(guān)于Web 2.0的事情。它沒有在一夜之間涌現(xiàn)。事實(shí)上，它已經(jīng)存在了許多 年，現(xiàn)在逐漸的進(jìn)入我們的生活，它包括許多技術(shù)，這些技術(shù)我們都已經(jīng)聽過如 JavaScript，XML 的，ASP.Net 和 PHP / Perl，My

3、SQL 和等，這些是處理網(wǎng)絡(luò)數(shù) 據(jù)的不同方式。軟件公司開始使用這些和其他類似的技術(shù)到應(yīng)用程序當(dāng)中。我們 都聽過內(nèi)聯(lián)網(wǎng)和知識(shí)管理解決方案和在線客戶關(guān)系管理等套件，這些都是以某種 方式來實(shí)現(xiàn)對(duì)建立下一代網(wǎng)絡(luò)技術(shù)的。不幸的是，它們?cè)谶^去都被忽視了。開始慢慢的有些人提出這些技術(shù)運(yùn)用在實(shí)際創(chuàng)造中使用，這些技術(shù)開始慢慢 的被人們注意。我們大家都聽說過博客，維基百科，YouTube以及Flickr，等等， 這些都轉(zhuǎn)化為一個(gè)平臺(tái)的，而不是靜態(tài)信息來源網(wǎng)絡(luò)。博客是讓普通用戶在網(wǎng)上 發(fā)帖，通過帖子把別人不知道的事用HTML發(fā)表出來。維基的思想是讓用戶可以 在線編輯發(fā)表意見。YouTube和Flickr不需要介紹。

4、他們已經(jīng)成為社會(huì)網(wǎng)絡(luò)世 界的火炬手。當(dāng)有人說起Web 2.0，它們的名字總是被人們第一個(gè)想起。所用通 過申請(qǐng)得到網(wǎng)上新的身份的用戶就不僅可以訪問數(shù)據(jù)，還可以參與到數(shù)據(jù)的增加 中。在瀏覽器中的應(yīng)用中，用戶可以自由的修改實(shí)時(shí)內(nèi)容，多個(gè)用戶之間也可以 相互交流。用戶可以從其他的網(wǎng)站中得到內(nèi)容而積累的內(nèi)容可以形成自己的網(wǎng) 站，現(xiàn)在創(chuàng)辦基于Web的桌面，觀看視頻Web瀏覽器，博客，所有這些現(xiàn)在已經(jīng) 實(shí)現(xiàn)，在網(wǎng)絡(luò)技術(shù)的發(fā)展要像它表示感謝。Web 2.0的出現(xiàn)，也為企業(yè)提供了一些商機(jī)。隨著應(yīng)用網(wǎng)站如維基，博客等 的出現(xiàn)能夠簡易的將信息聚合在一起，就可以使它們的解決方案更加的有互動(dòng) 性。為用戶提供有用的信息。

5、當(dāng)提及Web 2.0技術(shù)成功的背后支持，AJAX是出 現(xiàn)的第一個(gè)名稱。因此，讓它引路，讓我們看看一些其他的塑造了新的網(wǎng)絡(luò)的基 本技術(shù)。AJAX今天，每當(dāng)?shù)诙€(gè)互聯(lián)網(wǎng)用戶出現(xiàn)就有一個(gè)Gmail賬戶。當(dāng)我們要上傳和分 享在網(wǎng)絡(luò)上的圖片的時(shí)候，大多數(shù)人都會(huì)使用Flickr。當(dāng)我們?cè)谝粋€(gè)地區(qū)旅游 的時(shí)候，我們一般會(huì)使用谷歌地圖來定位。當(dāng)然，你必須認(rèn)識(shí)到，一個(gè)全新的動(dòng) 態(tài)Web應(yīng)用程序正在出現(xiàn)新品種。這些應(yīng)用程序大多是外觀和風(fēng)格類似的桌面應(yīng) 用程序。AJAX （異步JavaScript和XML）是一種技術(shù)。它使網(wǎng)頁交換服務(wù)器與 少量的數(shù)據(jù)反應(yīng)，在背后，使整個(gè)網(wǎng)頁并不需要重新加載每次用戶發(fā)出請(qǐng)求。這 樣有

6、助于改善網(wǎng)站總體的交互性，速度性，功能和網(wǎng)頁的可用性。JavaScript 是主要的編程語言，其中的AJAX函數(shù)用來被調(diào)用的和使用XML的異步檢索到的 數(shù)據(jù)的格式和保存。作為一種跨平臺(tái)的技術(shù)，使之可以在不同的操作系統(tǒng)，計(jì)算 機(jī)體系結(jié)構(gòu)和Web瀏覽器中使用。Web應(yīng)用程序總是比桌面應(yīng)用程序有更多的實(shí) 惠，他們很容易使用，安裝和發(fā)展，但缺乏交互性。恰恰AJAX的解決了這個(gè)問 題。AJAX結(jié)合了多種技術(shù)，它們都有獨(dú)自蓬勃發(fā)展的權(quán)利。以一種強(qiáng)大的方式結(jié) 合在一起。我們用XHTML和CSS組成一種標(biāo)準(zhǔn)的演示方式。動(dòng)態(tài)顯示和交互可以 合并使用文檔對(duì)象模型。數(shù)據(jù)互換和操縱，主要是XML和XSLT工作。異步數(shù)

7、據(jù)檢索在XMLHttpRequest的JavaScript的幫助下完成，在客戶端生成檢 索結(jié)果，結(jié)合每個(gè)事件實(shí)現(xiàn)動(dòng)態(tài)顯示與信息交互。XMLHttpRequest對(duì)象一直是 AJAX成功實(shí)現(xiàn)資料顯示和相互作用的關(guān)鍵。因?yàn)樗狗?wù)器的異步數(shù)據(jù)交換得 以實(shí)現(xiàn)。一個(gè)企業(yè)也可以實(shí)現(xiàn)在其門戶網(wǎng)站的AJAX的應(yīng)用。有AJAX你可以建立豐富 的應(yīng)用和動(dòng)態(tài)的內(nèi)容，還可以提供簡單的功能，例如拖放和自動(dòng)完成。AJAX是 一個(gè)框架結(jié)構(gòu)和得到現(xiàn)在被人們喜愛的Java和.NET的支持。在微軟的ASP 2.0 介紹后，與Web 2.0兼容的Web應(yīng)用程序開發(fā)這件事情就變得簡單了很多。在某 種程度上，你甚至不必是一個(gè)AJAX

8、的專家就可以很好的使用它。有ASP 2.0， Web開發(fā)人員就可以讓工作中的一部分與服務(wù)器通信獨(dú)立.mash ups這些增值服務(wù)是由第三方提供輕量級(jí)的工具，為Web應(yīng)用程序的綜合服務(wù)。 主要是mash-ups工具是源自與第三方通過一個(gè)公共接口或API得到的內(nèi)容。例 如，在你的個(gè)人主頁中一個(gè)小模塊展示本地的天氣預(yù)測，在另外的小模塊中顯示 您的新聞標(biāo)題，這是以混合搭配的形式展開的行動(dòng)。一個(gè)mash-ups的應(yīng)用程序一般包括三個(gè)不同的參與者，艮即API/內(nèi)容提供 者，mash-ups的位置和客戶端瀏覽器界面。API /內(nèi)容提供商提供內(nèi)容來源。它們以網(wǎng)絡(luò)協(xié)議形式通過API提供內(nèi)容。例如提供的REST的

9、檢索內(nèi)容，Web 服務(wù)或RSS/Atom供稿。有一些網(wǎng)站，不提供內(nèi)容檢索的設(shè)備。因此由mash-up技術(shù)來提取這些網(wǎng)站 的內(nèi)容。屏幕抓取是一個(gè)方法，用一個(gè)工具嘗試提取內(nèi)容提供商，嘗試把提供商 的頁面格式化為XML數(shù)據(jù)檢索的內(nèi)容，難后發(fā)送一個(gè)作為HTTP請(qǐng)求的響應(yīng)返回 的信息。在另一方面，其中一個(gè)mash - up網(wǎng)站提供它的邏輯地址。mash-ups 網(wǎng)站同樣可以支持對(duì)傳統(tǒng)的Web應(yīng)用服務(wù)器端動(dòng)態(tài)內(nèi)容生成技術(shù)，如 Java servlet的和PHP或ASP。最后，mash - up的應(yīng)用程序呈現(xiàn)在客戶的瀏覽器界 面，并在實(shí)際中與用戶交互發(fā)生。有趣的是，這些mash - ups為企業(yè)開辟了新的途

10、徑，就因?yàn)樗尸F(xiàn)出的可 互操作性。例如：一個(gè)SAP ERP與Java應(yīng)用程序或一個(gè)PHP的網(wǎng)站通信，并提 出了統(tǒng)一的結(jié)果給用戶。mash - ups的內(nèi)容來源也可以是不同的Web服務(wù)器。 讓mash - ups技術(shù)進(jìn)入企業(yè)的內(nèi)部網(wǎng)，這是一件意義重大的事。這將提供一個(gè) 平臺(tái)，可以從不同的應(yīng)用程序來訪問企業(yè)的網(wǎng)站。作為門戶網(wǎng)站將使用Web瀏覽 器，要訪問的時(shí)候就不需要安裝客戶端了，這樣可以適用于不同的應(yīng)用環(huán)境，從 而使員工能夠靈活的從不同的地點(diǎn)使用。企業(yè)只需要在網(wǎng)絡(luò)上擁有自己的Web 瀏覽器界面。Web feed它使用特定的數(shù)據(jù)格式向訂閱的用戶提供更新的內(nèi)容。代理商提供一個(gè)Web feed，其內(nèi)容

11、滿足客戶的訂閱。Web feed的內(nèi)容通過網(wǎng)絡(luò)聚合集中在一個(gè)模塊 里。這個(gè)模塊可以是一個(gè)客戶端軟件或是一個(gè)基于Web的服務(wù)，這種模塊就像博 客中的一塊內(nèi)容，比如新聞等獨(dú)自在一個(gè)模塊。Web feed的功能簡單的說就是從Web瀏覽器中拖一個(gè)鏈接到這個(gè)模塊當(dāng)中。 代理商提供內(nèi)容，在其網(wǎng)站上發(fā)表滿足客戶的訂閱需求。并通過一個(gè)模塊在它們 的電腦上聚合這些內(nèi)容。再聚合查詢?cè)诜?wù)器上與這些有關(guān)的新的內(nèi)容，然后把 新的內(nèi)容用說明的方式顯示出來，或者下載到客戶端瀏覽器。Web feeds被設(shè)計(jì)成機(jī)器可讀而不是人可讀，因此它們可以被用來自動(dòng)的傳 遞信息從一個(gè)網(wǎng)站到另一個(gè)網(wǎng)站在沒有人的操縱下。它的兩個(gè)主要的Web

12、 feed 格式是RSS和Atom。RSS：，當(dāng)被用于提供者和聚合者用于網(wǎng)站的摘要和聚合的時(shí)候，它就是一中 基于XML的協(xié)議。Rss以一種簡單的XML文件形式被這些網(wǎng)站的所有者保留和自 動(dòng)更新，還可以用rss閱讀軟件接收和和閱讀。Rss是一種基于XML的文件有一 個(gè)全球標(biāo)準(zhǔn)RSS 2.0格式標(biāo)記主要網(wǎng)站和為提供項(xiàng)目設(shè)置標(biāo)簽，代表已發(fā)表的鏈 接/網(wǎng)站上的更新。每一個(gè)這樣的項(xiàng)目標(biāo)簽包括一個(gè)標(biāo)題，代表該項(xiàng)目的簡短描 述和對(duì)XML格式的全文鏈接。在RSS閱讀器軟件下載該XML文件并分析其形成的 HTML，就獲得了用戶在瀏覽器中的超鏈接的形式的顯示數(shù)據(jù)，并返回原來的網(wǎng)站。Atom:（ATOM是一種訂閱網(wǎng)

13、志的格式）有兩種標(biāo)準(zhǔn)是：一種基于XML的文 檔格式以及基于HTTP的創(chuàng)建和更新Web資源的協(xié)議。Atom的發(fā)展是彌補(bǔ)了 RSS 互動(dòng)性的不足和借鑒了各種版本RSS的使用經(jīng)驗(yàn)。盡管在功能上RSS和Atom是 一些類似，它與RSS相比來講，有更大的彈性，使開發(fā)應(yīng)用程序開發(fā)更容易。RSS可能也包含純文本或者是脫離有效的HTML的文件。現(xiàn)在還沒有辦法說 明這兩種提供。與此相反的是Atom用一個(gè)明確的標(biāo)記有效的文件。因此，更多 的有效類型文件例如純文本，轉(zhuǎn)義的HTML和XHTML，XML的Base64編碼的二進(jìn) 制文件可以在Atom中和被提及的第三方內(nèi)容同時(shí)使用。如文件，視頻和音頻流 也可以提出和使用。

14、RSS和Atom還有一個(gè)不同的是：Atom包括XML模式，而RSS 沒有。網(wǎng)絡(luò)訂閱源對(duì)任何企業(yè)都是有用的，如果他們計(jì)劃納入其門戶的解決方案。 它可以很好的用于在顯示企業(yè)數(shù)據(jù)，以及最新的軟件建設(shè)，網(wǎng)絡(luò)的正常運(yùn)行，即 將舉行的公司會(huì)議和其他項(xiàng)目中。企業(yè)2.0之路協(xié)作和資源共享已經(jīng)表明了，企業(yè)運(yùn)用Web 2.0的前景，企業(yè)可以從這兩點(diǎn) 上獲益。博客和維基是兩個(gè)協(xié)作技術(shù)，企業(yè)可以把它們?nèi)谌胨麄兊拈T戶解決方案。 添加博客，企業(yè)門戶將增加人類的互相聯(lián)系和操作促進(jìn)和客戶或管理雇員的關(guān) 系。同樣，一個(gè)中心信息庫可以在維基的幫助下創(chuàng)建。正如我們所講的mash - ups和Web feed它們可以有效的在企業(yè)使用

15、窗口。 通過Web feed，員工可以保持掌握最新的企業(yè)應(yīng)用中存儲(chǔ)的數(shù)據(jù)資料mash - ups 在另一方面，提供豐富的用戶界面，使用戶更容易找到并使用信息，他可以按需 要分配任務(wù)和角色。很多軟件作為服務(wù)模式的應(yīng)用程序正在開發(fā)中，作為Web應(yīng)用程序使用。目 前，企業(yè)已經(jīng)使用這種模式的軟件在客戶關(guān)系管理，人力資源，會(huì)計(jì)和電子郵件 領(lǐng)域。各部門可以根據(jù)需要申請(qǐng)并安裝這些軟件并通過網(wǎng)絡(luò)來訪問。現(xiàn)在，這些 應(yīng)用程序可以提供在互聯(lián)網(wǎng)上的服務(wù)可以按要求在客戶機(jī)上執(zhí)行Web瀏覽器，不 需要在個(gè)別電腦上安裝應(yīng)用程序。在使用的是他們的門戶，使員工可以借助這些 標(biāo)簽通過Internet遠(yuǎn)程訪問應(yīng)用程序，這些標(biāo)簽工

16、具構(gòu)成了門戶網(wǎng)站使其用戶 可以使用這些標(biāo)簽來定義它們的公共數(shù)據(jù)庫的內(nèi)容。以便隨后其他員工可以用這 些標(biāo)簽來以及它們自己增加改善搜索的標(biāo)簽來訪問這些文件。這種新方法可以為企業(yè)帶來新的業(yè)務(wù)渠道，將幫助他們?cè)黾訂T工和客戶以及 合作伙伴之間的互動(dòng)性，這對(duì)任何企業(yè)增長的都是有幫助的。Web 3.0的難道未來？當(dāng)我們廣泛談?wù)揥eb 2.0技術(shù)以及一個(gè)企業(yè)如何能夠從中受益時(shí)，有些人已 經(jīng)在一個(gè)更新的Web版本會(huì)談的Web 3.0，也被稱為，語義網(wǎng)。我們的目標(biāo)是 使計(jì)算機(jī)能夠理解信息和進(jìn)行繁復(fù)的任務(wù)，如尋找，分享，結(jié)合網(wǎng)上的信息。隨 著Web 3.0的，網(wǎng)上的內(nèi)容雖然將不局限于只讓人類理解的格式，但它有可能超

17、 越為一種形式：軟件代理可以閱讀，理解，從而使機(jī)器使用它們查找，共享和整 合更多的信息，這樣更方便于我們。它是從蒂姆伯納斯-李的構(gòu)想中得到的 信息和知識(shí)的數(shù)據(jù)交換的網(wǎng)站普遍的媒介。一些關(guān)鍵技術(shù)，最終構(gòu)成Web 3.0的技術(shù)可能會(huì)是RDF （資源描述框架）， 用一種簡單的語言來表達(dá)數(shù)據(jù)模型和它們的關(guān)系。OWL （Web本體語言）是另一 種構(gòu)成Web 3.0的技術(shù)。它增加了更多的描述屬性和類的詞匯，以及介紹了階級(jí) 之間的關(guān)系。XML是顯然和上述兩種技術(shù)一起就形成了 Web3.0的主流技術(shù)。這還有些時(shí) 間才能看到它的到來。但是，這將對(duì)的桌面應(yīng)用程序產(chǎn)生威脅。這只是個(gè)時(shí)間問 題。至此，讓我們拭目以待。

18、From ： HYPERLINK /content/search/showarticle.asp?artid=99624 /content/search/showarticle.asp?artid=99624Web Technologies:Enter the NextGone are the days when Internet was only a bunch of static webs. Today, its a live and happening place, full of interactivity, thanks to a set of technologies collec

19、tively known as Web 2.0. Its become so popular that now, even enterprises want to use them. In this story, we explore these technonolgies, and how they can power next-generation enterprise portals. Plus, we take a peek into the future of Web 2.0In order to understand and appreciate the next generati

20、on of web technologies, its important to understand what the current generation has to offer. For a long time, websites were nothing but a bunch of web pages put together for people to click and browse. While it proved to be a terrific source of information, there were many limitations in it. For on

21、e, people couldnt interact on it. There was just one sea of pages to go through. If two people were browsing the same site, they had no way of knowing that. If you wanted to modify a web page or a part of it, then you had to be familiar with HTML coding. Plus, you had to modify the complete web page

22、. There was no way to change parts of it. Over a period of time, websites started springing up like mushrooms on a rotting log. The situation became that if it moves, then it must have a website. With so many websites offering the same set of static pages, life became rather boring on the Internet.

23、Something was needed to break this monotony.That something was web 2.0. It didnt spring up over night. In fact, it has been there for many years now, gradually getting into our lives. It comprises of many technologies that weve all heard of already, like JavaScript, XML, ASP.Net, PHP/Perl, MySQL, et

24、c. These gave the web a different way of dealing with data. Using these and other similar technologies, software companies started giving a web front-end to all their existing applications. Others started building applications solely for the web. Weve all heard of Intranets and knowledge management

25、solutions, online CRM packages, etc. All of these have in some way or the other contributed to building the next generation web technologies. Unfortunately, theyve all gone by relatively unnoticed.It was only after some one put these technologies to some real creative use that it started getting not

26、iced. All of us have heard of blogging, wikipedia, YouTube, Flickr, etc. All of these have converted the web into more of a platform rather than a static source of information. Blogging allowed ordinary users to post their thoughts on websites without knowing a word of HTML. Wikipedia allowed users

27、to edit what others have written online. YouTube and Flickr need no introduction. Theyve become the torch bearers for the world of social networking. Their names are the first to come to mind whenever someone says web 2.0. All these applications have given the web a new identity. Users can now, not

28、only access data, but also participate and add value to applications. Integration of applications in the browser, freedom for the user to modify content in real-time, interaction between several users, accumulation of content from other sites and feeding of the same into ones own site, having the de

29、sktop hosted on Web, watching video on a Web browser, blogging-all these are possible now, thanks to major development in the Web technologies.The emergence of Web 2.0 offers several opportunities for enterprises as well. With the integration of several applications, like Wiki, blogging, RSS feeds,

30、they can make their portal solutions much more interactive and useful for users. When ever reference to technologies behind Web 2.0 is made, AJAX is the first name that comes up. So, let us start with it and as we move on, we will cover some other essential technologies that are shaping up the new W

31、eb.AJAXToday, every second Internet user has a Gmail account, most of us use flickr to upload and share our pictures on the Web, and some of us use Google Maps to locate the area we are travelling. Surely, you must have realized that a completely new variety of dynamic Web applications are emerging.

32、 Most of these applications have looks and feel similar to that of desktop applications. AJAX (Asynchronous JavaScript and XML) is the technology that has enabled this. It makes webpages more responsive by exchanging small amounts of data with the server, behind the scene, so that the entire webpage

33、 doesnt need to reload every time the user makes a request. This helpsimprove the overall interactivity, speed, functionality and usability of the webpage. JavaScript is the main programming language wherein AJAX function calls are made and using XML the asynchronously retrieved data is formatted an

34、d kept. Being a cross-platform technology enables it to be used across different operating systems, computer architectures and Web browsers. Web apps always had more benefits than desktop apps. They were easy to use, install, and develop, but interactivity was lacking. AJAX solves that problem as we

35、ll.AJAX is a combination of several technologies each thriving in its own right, gelling together in a powerful way. We can incorporate a standard-based presentation using XHTML and CSS. Dynamic display and interaction can be incorporated using Document Object Model. Data interchanging and manipulat

36、ion is mainly the work of XML and XSLT. Data is retrieved asynchronously with the help of XMLHttpRequest and finally JavaScript, residing on client side, binds everything together and dynamically displays and interacts with the information. XMLHttpRequest object has been the key to the success of AJ

37、AX, as it enables asynchronous data exchange with servers.An enterprise can also implement AJAX in its portal. With AJAX you can build applications with rich and dynamic content, by offering simple features like drag and drop and auto-completion. AJAX is a framework model and is now relishing suppor

38、t from both Java and .NET. After the introduction of Microsofts ASP 2.0, the things have become still easy for developers working on Web 2.0 compliant Web applications. To the extent that you dont even need to be an expert in AJAX to use it. With ASP 2.0, a Web developer can compose a page out of se

39、parate working parts that communicateMash-upsThese are value added services in the form of lightweight tools provided by third parties to be integrated into a Web application. Mostly, mash-ups source the content from a third party via a public interface or API. For example, the small box on your per

40、sonal homepage showing you the local weather forecast and another box showing you news headlines, are forms of mash-up.A mash-up application would generally comprise of three different participants, namely, API/content provider, mash-up site and clients browser interface. The API/content providers a

41、re the facilitators of content being mashed (sourced). They provide the content for retrieval by making it available through APIs, which generally are in the form of Web protocols such as REST, Web services, or RSS/Atom feeds.There are some sites that do not provide facility for content retrieval, f

42、or that there are mash-up techniques to extract content from such sites. Screen scraping is a process by which a tool attempts to extract information from the content provider by attempting to parse the providers webs and formatting the retrieved content as XML data that is sent back as a response t

43、o an HTTP request. On other hand, a mash-up site is one where mash-up logic resides. The mash-ups can be implemented similarly to traditional Web applications using server-side dynamic content generation technologies, like Java servlets, PHP, or ASP. Finally, mash-up application is rendered on clien

44、ts browser interface and where actual user interaction takes place.Interestingly, these mash-ups have opened new avenues for enterprises, as it renders interoperability. For instance, an SAP ERP communicating with a Java application or a PHP website and presenting a unified result to the user. Mash-

45、ups can also be used to source contents from disparate Web services and so, it makes sense to implement mash-ups into an enterprise intranet. This will provide enterprises with a common platform, from which contents of different applications can be accessed. As portal would be using a Web browser, t

46、here would not be a need to install client-environments for different applications, and thus would provide employees the flexibility to work from different locations. They just need being on the Net and should be having a Web browser to interface.Web feedIt is a data format, which is generally used

47、to facilitate users with the content that is frequently updated. Content distributors syndicate a Web feed and require users to subscribe to it. The entire collection of Web feed is aggregated at one spot with the use of Internet aggregators. An aggregator is a client-software or Web based service t

48、hat aggregates syndicated Web content like blogs, news headlines etc, at a single location.The functionality of Web feed is, as simple as, dragging a link from the Web browser to the aggregator. The content provider publishes a feed-link on its website and the end users subscribe to it, via an aggre

49、gator that is hosted on their machine. Aggregator enquires about any new content uploaded on the server and then either makes note of the new content or downloads it to the clients browser.Web feeds are designed to be machine-readable rather than being human-readable, hence they can be used to autom

50、atically transfer information from one website to another without human intervention. The two main Web feed formats are RSS and Atom.RSS: RSS (Really Simple Syndication) is an XML based protocol, which when used with feeds and aggregators, offers website summaries and syndications. The RSS feeds tak

51、e the form of a single XML file that can be hosted and updated automatically by the website owners and accessed and read by RSS feed software. The RSS feed is an XML based document that has a global container RSS tag of format 2.0. This XML file has tags that define the main website, and provides se

52、t of item-tags representing links that have been published/updated on the site. Each such item-tag consists of a title, short description of the items and the links to the full text in XML format. The RSS feed reader software downloads this XML file and parses it to form HTML data that gets displaye

53、d on the users browser in the form of hyperlinks, pointing to the original website.Atom: There are two standards related to Atom-the Atom Syndication Formats is an XML language and the Atom Publishing Protocol is a simple HTTP-based protocol for creating and updating Web resource. The development of

54、 Atom was a result of incompatible version of RSS syndication and poor interoperability. Even though the functionality of RSS and Atom are some what similar, the intention with Atom is to make development of application easier with Web syndication feeds.RSS may either contain plain text or escaped H

55、TML as a payload, and there is no way to indicate which of the two is provided. In contrast to this, Atom uses an explicitly labeled payload container. Hence, more variety of payload types, like plain text, escaped HTML, XHTML, XML, Base64-encoded binary, is available in Atom and at the same time re

56、ference to third party content, like documents, video and audio streams can also be made available. Another point of difference between Atom and RSS is that Atom includes XML schema, whereas RSS does not.Web feeds are useful for any enterprise, if they plan to integrate it in their portal solution.

57、It can be used for showing corporate data as well, such as the latest software build status, network uptime, upcoming corporate meetings or other dashboard-like features.Road to Enterprise 2.0Collaboration and resource sharing have been two such headways shown by Web 2.0 that have envisioned enterpr

58、ises to try benefiting from them. Blogging and Wiki are two collaboration techniques that enterprises can look forward to integrate into their portal solutions. Adding a blog to enterprises portal will add a human interactive touch to a vendor-customer or management-employee relationship. Similarly,

59、 a central information repository can be created with the help of Wiki.As we have talked of Web feeds and mash-ups, they can be efficiently used in an enterprise. Through Web feeds, employees can keep themselves abreast with latest information of data stored in corporate applications. On other hand

60、mash-ups provide rich user interfaces that address the need for increased worker productivity, by making it easier for the user to find and use the information that he needs for a particular task or role.Many SaaS (Software as a Service) model based applications are now being developed, to be used a