java-畢設(shè)論文-英文翻譯(編輯修改稿)
2024-08-31 22:50 本頁(yè)面
【文章內(nèi)容簡(jiǎn)介】 theformbacktotheserver.ThissubmissionpassesthroughtheCommonGatewayInterface(CGI)providedonallWebservers.ThetextwithinthesubmissiontellsCGIwhattodowithit.Themostmonactionistorunaprogramlocatedontheserverinadirectorythat’stypicallycalled“cgibin.”(IfyouwatchtheaddresswindowatthetopofyourbrowserwhenyoupushabuttononaWebpage,youcansometimessee“cgibin”withinallthegobbledygookthere.)Theseprogramscanbewritteninmostlanguages.Perlhasbeenamonchoicebecauseitisdesignedfortextmanipulationandisinterpreted,soitcanbeinstalledonanyserverregardlessofprocessororoperatingsystem.However,Python(myfavorite—see)hasbeenmakinginroadsbecauseofitsgreaterpowerandsimplicity.ManypowerfulWebsitestodayarebuiltstrictlyonCGI,andyoucaninfactdonearlyanythingwithCGI.However,WebsitesbuiltonCGIprogramscanrapidlybeeoverlyplicatedtomaintain,andthereisalsotheproblemofresponsetime.TheresponseofaCGIprogramdependsonhowmuchdatamustbesent,aswellastheloadonboththeserverandtheInternet.(Ontopofthis,startingaCGIprogramtendstobeslow.)TheinitialdesignersoftheWebdidnotforeseehowrapidlythisbandwidthwouldbeexhaustedforthekindsofapplicationspeopledeveloped.Forexample,anysortofdynamicgraphingisnearlyimpossibletoperformwithconsistencybecauseaGraphicsInterchangeFormat(GIF)filemustbecreatedandmovedfromtheservertotheclientforeachversionofthegraph.Andyou’venodoubthaddirectexperiencewithsomethingassimpleasvalidatingthedataonaninputform.Youpressthesubmitbuttononapage。thedataisshippedbacktotheserver。theserverstartsaCGIprogramthatdiscoversanerror,formatsanHTML pageinformingyouoftheerror,andthensendsthepagebacktoyou。youmustthenbackupapageandtryagain.Notonlyisthisslow,it’sinelegant.Thesolutionisclientsideprogramming.MostmachinesthatrunWebbrowsersarepowerfulenginescapableofdoingvastwork,andwiththeoriginalstaticHTMLapproachtheyaresittingthere,justidlywaitingfortheservertodishupthenextpage.ClientsideprogrammingmeansthattheWebbrowserisharnessedtodowhateverworkitcan,andtheresultfortheuserisamuchspeedierandmoreinteractiveexperienceatyourWebsite.Theproblemwithdiscussionsofclientsideprogrammingisthattheyaren’tverydifferentfromdiscussionsofprogrammingingeneral.Theparametersarealmostthesame,buttheplatformisdifferent。aWebbrowserislikealimitedoperatingsystem.Intheend,youmuststillprogram,andthisaccountsforthedizzyingarrayofproblemsandsolutionsproducedbyclientsideprogramming.Therestofthissectionprovidesanoverviewoftheissuesandapproachesinclientsideprogramming.PluginsOneofthemostsignificantstepsforwardinclientsideprogrammingisthedevelopmentoftheplugin.This
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