【正文】 In 1972, mercial services using were deployed, and later used as an underlying infrastructure for expanding TCP/IP networks.Today, puter networks are the core of modern munication. All modern aspects of the public switched telephone network (PSTN) are putercontrolled. Telephony increasingly runs over the Internet Protocol, although not necessarily the public Internet. The scope of munication has increased significantly in the past decade. This boom in munications would not have been possible without the progressively advancing puter network. Computer networks, and the technologies that make munication between networked puters possible, continue to drive puter hardware, software, and peripherals industries. The expansion of related industries is mirrored by growth in the numbers and types of people using networks, from the researcher to the home user.An interconnected collection of autonomous puters (unique identity) is known as a puter network.PropertiesA puter network has the following properties:Facilitates interpersonal municationsPeople can municate efficiently and easily via , instant messaging, chat rooms, telephone, video telephone calls, and video conferencing.Allows sharing of files, data, and other types of informationAuthorized users may access information stored on other puters on the network. Providing access to information on shared storage devices is an important feature of many networks.Allows sharing of network and puting resourcesUsers may access and use resources provided by devices on the network, such as printing a document on a shared network printer. Distributed puting uses puting resources across a network to acplish tasks.May be insecureA puter network may be used by puter crackers to deploy puter viruses or puter worms on devices connected to the network, or to prevent these devices from accessing the network (denial of service).May interfere with other technologiesPower line munication strongly disturbs certain[3]forms of radio munication, ., amateur radio. It may also interfere with last mile access technologies such as ADSL and VDSL.May be difficult to set upA plex puter network may be difficult to set up. It may be costly to set up an effective puter network in a large organization.Communication mediaComputer networks can be classified according to the hardware and associated software technologies used to interconnect the individual network devices. These technologies include electrical cable (HomePNA, power line munication, ), optical fiber, and radio waves (wireless LAN). In the OSI model, these are located at levels 1 and 2.A widelyadopted family of munication media is collectively known as Ethernet. Defined by IEEE 802, it uses various standards and media to enable munication between devices. Wireless LAN technology is designed to connect devices without wiring. These devices use radio waves or infrared signals as a transmission medium.Wired technologiesThe order of the following wired technologies are, roughly, from slowest to fastest transmission speed.Twisted pair wire is the most widely used medium for telemunication. Twistedpair cabling consist of copper wires that are t。 Also in 1965, the first widely used telephone switch that implemented true puter control was introduced by Western Electric. Throughout the 1960s, Leonard Kleinrock, Paul Baran and Donald Davies independently conceptualized and developed network systems which used packets to transfer information between puters over a network. In 1962, . Licklider developed a working group he called the Intergalactic Computer Network, a precursor to the ARPANET, at the Advanced Research Projects Agency (ARPA). In the late 1950s, early networks of municating puters included the military radar system SemiAutomatic Ground Environment (SAGE).s puter via removable storage media (such as flash drives).我會在以后的工作和學(xué)習(xí)中不斷完善自己，為我最熱愛的母校爭光，為自己翻開輝煌的新篇章。我還要感謝我的母校——陜西理工學(xué)院，以及在大學(xué)四年生活中給予我關(guān)心和幫助的老師和同學(xué)，是他們教會了我專業(yè)的知識和做人的道理。此次畢業(yè)設(shè)計對提高我的編程技術(shù)等方面都由許多益處。在此特別感謝李娜老師的大力幫助。就比如說在這次的設(shè)計，我不但對JSP和MS SQL SERVER2000有了深刻的認(rèn)識，積累了使用軟件工程的思想來開發(fā)軟件的經(jīng)驗(yàn)，同時最重要的是摸索出了一套考慮問題和解決問題的方法，這對于我以后的學(xué)習(xí)受益匪淺?？傊ㄟ^這次設(shè)計,我深刻體會到要做好一個完整的事情，需要有系統(tǒng)的思維方式和方法，對待一個新的問題，要耐心、要善于運(yùn)用已有的資源來充實(shí)自己。(3)在設(shè)計過程中，遇到很多困難，我學(xué)會通過別人的代碼理解語言的含義但這并不是抄襲，然后根據(jù)自己的設(shè)計要求編寫代碼。(2)由于開始時對系統(tǒng)缺乏整體認(rèn)識，不具備軟件開發(fā)思想，對系統(tǒng)的功能需求分析的要求認(rèn)識不夠清楚，使得后續(xù)的工作不得不經(jīng)常返回去修改數(shù)據(jù)表和個別代碼。前臺主要是后臺信息的管理，以及個人或企業(yè)用戶登錄發(fā)布或修改自己信息。系統(tǒng)基本符合網(wǎng)站風(fēng)格。比如在servlet路徑配置時因粗心錯誤導(dǎo)致運(yùn)行導(dǎo)致所報錯誤。主頁面的登錄模塊測試：測試流程：(1)打開系統(tǒng)首頁，輸入錯誤的登錄信息 (2)登錄 (3)輸入正確的登錄信息 (4)登錄(5)測試結(jié)果（1）測試用例（1）（用戶名不為空，密碼為空）實(shí)際結(jié)果與預(yù)期一致，如圖9所示: （2）測試用例（2）（用戶名為空，密碼為空）實(shí)際結(jié)果與預(yù)期一致，如圖10所示: （3）測試用例（3）（用戶名不為空，密碼不為空，但不相符）實(shí)際結(jié)果與預(yù)期一致，如圖11所示: （3）測試結(jié)果:模塊名稱測試用例預(yù)期結(jié)果實(shí)際結(jié)果登錄模塊用戶名：asddfg 密碼：123456 彈出錯誤提示，請輸入用戶名登錄失敗，提示請輸入用戶名登錄模塊用戶名： qwert密碼：456789 彈出錯誤提示，請輸入密碼失敗，提示輸入密碼登錄模塊用戶名：qazxsw密碼：111222彈出錯誤提示，用戶名或者密碼錯誤登錄失敗，提示用戶名或者密碼錯誤在程序設(shè)計實(shí)現(xiàn)的過程中不可避免的會產(chǎn)生各種難以預(yù)料的錯誤，如書寫錯誤、傳值類型不一致、參數(shù)傳遞問題等等。 在測試之初，由于將數(shù)據(jù)庫中的數(shù)據(jù)是隨便輸入，沒有實(shí)用性，為了使系統(tǒng)更加完善，在系統(tǒng)測試的過程中，本系統(tǒng)將一開始編程隨便輸入的數(shù)據(jù)全部清理后，輸入了一些有效的測試數(shù)據(jù)，這樣可以更真實(shí)的反映系統(tǒng)的功能實(shí)現(xiàn)情況。測試發(fā)現(xiàn)問題之后要經(jīng)過調(diào)試找出錯誤原因和位置，然后進(jìn)行改正。系統(tǒng)測試的任務(wù)是盡可能徹底的檢查出程序中的錯誤，提高軟件系統(tǒng)的可靠性，其目的是檢驗(yàn)系統(tǒng)“做得怎樣”。 } public String adminManage() 5系統(tǒng)測試在整個系統(tǒng)開發(fā)管理過程里邊，系統(tǒng)測試應(yīng)該算是一個非常重要并且漫長的的階段。 ()。 (admin)。 (userName)。登錄后，用戶才能實(shí)現(xiàn)自己特有的功能。 private TLiuyanDAO liuyanDAO。 private String huifu。 private String liuyanshi。 } final public void init(ServletConfig config) throws ServletException1界面顯示游客留言2實(shí)現(xiàn)管理員可以進(jìn)行回復(fù)的功能運(yùn)行如下圖: 流程圖如下：留言板源代碼：public class liuyanAction extends ActionSupport{ private Integer id。(3)運(yùn)行結(jié)果如下圖： 新聞添加修改流程圖如下所示： 、修改、刪除流程圖實(shí)現(xiàn)關(guān)鍵代碼如下：public class NewsServlet extends HttpServlet { private ServletConfig config?；谝陨显瓌t，給出系統(tǒng)示意界面如下： (1)系統(tǒng)運(yùn)行流暢,沒有