JSP技术---外文文献

实用文档外文文献JSPTechnologyandServletsJSPprofileJSP(JavaServerPages)isinitiatedbySunMicrosystems,Inc.,withmanycompaniestoparticipateintheestablishmentofadynamicwebpagetechnicalstandards.JSPtechnologysomewhatsimilartoASPtechnology,itisinthetraditionalHTMLwebpagedocument(*.htm,*.html)toinserttheJavaprogrammingparagraph(Scriptlet)andJSPtag(tag),thusJSPdocuments(*.jsp).UsingJSPdevelopmentoftheWebapplicationiscrossthatcanrunonLinux,isalsoavailableforotheroperatingsystems.JSPtechnologytousetheJavaprogramminglanguagepreparedbythecategoryofXMLtagsandscriptlets,toproducedynamicpagespackageprocessinglogic.Pagealsovisitbytagsandscriptletsexistintheservicessideoftheresourcesoflogic.JSPpagelogicandwebpagedesignanddisplayseparation,supportreusablecomponent-baseddesign,Web-basedapplicationdevelopmentisrapidandeasy.WebserverinthefaceofvisitsJSPpagerequest,thefirstimplementationoftheproceduresof,andthentogetherwiththeresultsoftheimplementationofJSPdocumentsinHTMLcodewiththereturntothecustomer.InserttheJavaprogrammingoperationofthedatabasecanbereorientedwebsites,inordertoachievetheestablishmentofdynamicpagesneededtofunction.JSPandJavaServlet,isintheimplementationoftheserver,usuallyreturnedtotheclientisanHTMLtext,aslongastheclientbrowserwillbeabletovisit.JSP1.0specificationofthefinalversionislaunchedinSeptember1999,Decemberhasintroduced1.1specificat实用文档ions.AtpresentrelativelynewisJSP1.2norms,JSP2.0normsofthedrafthasalsobeenintroduced.JSPpagesfromHTMLcodeandJavacodeembeddedinoneofthecomponents.JSscriptlanguagesynopsisJSisjavascrip,JavascriptisonekindthescriptlanguagewhichcomesbytheNetscapeLiveScriptdevelopment,themainpurposeistosolvetheserverterminallanguage,forinstancePerl,carry-overspeedquestion.Atthattimeservedtheendtoneedtocarryontheconfirmationtothedata,becausethenetworkspeedwasquiteslow,onlythen28.8kbps,theconfirmationstepwaste'stimeweretoomany.ThereforeNetscapebrowserNavigatorhasjoinedJavascript,hasprovidedthedataconfirmationbasicfunction.TheJavaScriptofficialnameis“ECMAScript”.ThisstandardbyECMAorganizationdevelopmentandmaintenance.ECMA262istheofficialJavaScriptstandard.ThisstandardbasedonJavaScript(Netscape)andJScript(Microsoft).Netscape(Navigator2.0)BrendanEichhasinventedthislanguage,startedfrom1996,alreadyappearedinallNetscapeandintheMicrosoftbrowser.TheECMA262developmentbeganin1996,in1997July,theECMAgeneralmeetinghasaccepteditsfirstedition.Thescriptusesonespecificdescriptivelanguage,restsoncertainformcompilationtobepossibletheexecutiondocument,isalsocalledasgreatorthebatchrundocument.Thescriptusuallymaytransfertemporarilybytheapplicationprocedureandcarryout.Eachkindofscriptpresentwidelyisappliedinthehomepagedesign,becausethescriptnotonlymayreducethehomepagethescaleandraisesthehomepagebrowsingspeed,moreovermayenrichthehomepageperformance,likeanimation,soundandso实用文档on.Citesamostcommonexample,whenweclickinthehomepagetheEmailaddresscantransferOutlookExpressortheFoxmailthiskindofmailsoftwareautomatically,isrealizesthroughthescriptfunction.Alsobecauseofscriptthesecharacteristics,thehumanwhoharborsulteriormotivesbysomeareoftenusing.Forexamplejoinssomedestructioncomputersystem'sorderinthescript,likethisworksastheuserbrowsinghomepage,oncetransfersthiskindofscript,willthencausetheuserthesystemtocomeundertheattack.Thereforetheusershouldactaccordingtovisitshomepagethetrustdegreeselectivesecurityrank,speciallyregardingtheseitselfcontentontheillegalhomepage,donotpermittheusescripteasily.Through“thesafeestablishment”thedialogbox,thechoice“thescript”underoptioneachkindofestablishmentmaywitheaserealizetoscriptbeingforbidandbeginsusing.JSPandServletsThetechnologyofJSPandServletisthemostimportanttechnologywhichuseJavatechnologytoexploitrequestofserver,anditisalsothestandardwhichexploitbusinessapplication.Javadevelopersprefertouseitforavarietyofreasons,oneofwhichisalreadyfamiliarwiththeJavalanguageforthedevelopmentofthistechnologyareeasytolearnJavatotheotherisapreparation,runeverywheretobringtheconceptofWebapplications,Toachieveaone-preparedeverywhererealized.Andmoreimportantly,iffollowedsomeoftheprinciplesofgooddesign,itcanbesaidofseparatingandcontenttocreatehigh-quality,reusable,easytomaintainandmodifytheapplication.Forexample,ifthedocumentinHTMLembeddedJavacodetoomuc实用文档h(script),willleadthedevelopedapplicationisextremelycomplex,difficulttoread,itisnoteasyreuse,butalsoforfuturemaintenanceandmodificationwillalsocausedifficulties.Infact,CSDNtheJSP/Servletforum,canoftenseesomequestions,thecodeisverylong,canlogicisnotveryclear,alargenumberofHTMLandJavacodemixedtogether.Thisistherandomdevelopmentofthedefects.EarlydynamicpagesmainlyCGI(CommonGatewayInterface,publicGatewayInterface)technology,youcanusedifferentlanguagesoftheCGIprograms,suchasVB,C/C++orDelphi,andsoon.ThoughthetechnologyofCGIisdevelopedandpowerful,becauseofdifficultiesinprogramming,andlowefficiency,modifycomplexshortcomings,itisgraduallybeingreplacedbythetrend.Ofallthenewtechnology,JSP/Servletwithmoreefficientandeasytoprogram,morepowerful,moresecureandhasagoodportability,theyha