汽车销售管理系统的设计与实现-外文翻译

外文原文Nowadays,e-Commerce(EC)playsapivotalroleintheWeb,involvingdifferentaspects(i.e.,technological,economic,legal,etc.)dependingonthecharacteristicsoftheECtransactions(Palopolietal.2006).Inparticular,ECtransactionsbetweenamerchantandacustomerarecommonlydenotedasBusiness-to-Customer(B2C)processes,thatcanbecomparedtotheretailtradeoftraditionalcommerce.Morespecifically,B2Cmarketinvolvesalargenumberofmerchantsinterestedinofferingproductsbyusingaconvenientmediaandcustomersthatdesiretopurchasethoseproducts.Inthiscontext,customersandmerchantscanexploitdifferentopportunities(Zwass2003)as:(i)absenceoftimeandspaceboundaries;(ii)simplicity,efficiencyandcomfortabilityofsalesandpurchases;(i)availabilityoflowcostsandseveralsaleterms.However,asignificantcustomer-merchantdistrust(Iglesias-Pradasetal.2013)stillpersistsinEC,mostlyduetotheabsenceofpersonalcontactsandtoalowacceptanceofthee-paymentmethodsforsecurityreasons.AB2Ctransactionisacomplexdecision-makingprocessconsistingofdifferentactivitiessuchassearchingforaproduct,selectingamerchant,negotiatingthebestpriceandsoon,thathavetobecarriedoutbybothcustomersandmerchants.Inthiscontext,arelevantattentionhasbeendevotedtoidentifythecustomersbehaviorandthecomplementarymerchantsbehavior.SeveralstudieshavebeenproposedintheliteratureinordertomodelthedifferentphasescomposingaB2Cprocess.SomeofthemarederivedbytraditionalretailcommerceastheNicosia(Nicosia1966)ortheEngelandBlackwell(Engeletal.1995)models,whileothershavebeenspecificallydesignedfortheWebastheNissensCommercemodel(Nissen1997),theE-CommerceValueChainmodel(Feldman1999)orrelatedtoSimonsdecisionmakingprocess,usuallyusedinDecisionSupportSystems(MilesandHowes2000).Asoneofthemostimportantmeanstocontrolsoftwarecomplexity,improvethequalityofsoftwaresystemsandsupportsoftwaredevelopmentandreuse,softwarearchitecturehasbeinggottenincreasingconcernsbymoreandmoreresearchersanddevelopersofsoftwaresinceithasbeenproposed.Today,softwarearchitecturehasbecomeanimportantresearchfieldinsoftwareengineering.Softwarearchitecturedescribesthepatternsusedinaparticulardomain,reflectsthecommonstructureandsemanticsthatextractfrommanysystemsinthedomain,andguidesdevelopersonhowthevariousmodulesandsubsystemswillbeeffectivelyorganizedintoacompletesystemwithhighquality.Comparedwithdesignpatternsandidioms,softwarearchitecturerepresentsthehighestratingpatternsinabstractionandgranularity.Inordertoreusethesepatternsinthesoftwaredevelopment,therearemanysoftwarearchitectureshavebeenproposed,suchasC/S,B/S,Pipe-Filter,theBlackboardsystem,andsoon.Moreover,advancedresearches,forexample,architecturedescriptionlanguage(ADL),Softwarearchitecturestyle,Architecture-basedsoftwaredevelopmentmethods,softwarearchitectureevaluation,architectureframeworkinthespecificfield,arebeingcarriedout.Alotofresearchinstitutesandsoftwareenterpriseshaveaccumulatedavailableassetsforsoftwarereuseandexperienceintheapplicationofsoftwarearchitecture,andachievedfruitfulresults.Three-tierC/S(Client-Server)andB/S(Browser-Server)hybridsoftwarearchitectureisadoptedintheBEIPsystem.TheC/Sarchitectureusedtohavetwotypesofhosts:clientsandservers.Thistypeofarchitectureissometimesreferredtoastwo-tier.Thetwotierarchitecturemeansthattheclientactsasonetierandapplicationincombinationwithserveractsasanothertier.Eachinstanceoftheclientsoftwarecansendtheusersrequesttooneormoreconnectedservers.Inturn,theserverscanaccepttheserequests,processthem,andreturntherequestedinformationtotheclient8.Further,servercanbecombinedwithapplicationserveranddatabaseserver,thusthethree-tierC/Sarchitectureisbuilt.Generallyspeaking,three-tierC/Sarchitectureisdividedintoexpressinglayer,businesslogiclayer,dataaccesslayer.Thismechanismenhancesthesystemsflexibilityandadaptability.SystembasedonB/Sarchitecturecanbeaccessedonlybyawebbrowser(suchasMicrosoftInternetExplorer,MozillaFirefox)andreachtheeffectofzeroclient.UnlikeC/Sarchitecture,theoperationsofdeployment,modificationandmaintenanceareperformedattheserverside.Theseoperationsarepreformedwithoutparticipationofclient,sosystemsmaintenanceandupgradesareeasierthanC/Sarchitecture.ButB/Sarchitecturehassomedisadvantages.Suchaslowsecurity,slowresponseindataquery.C/SandB/SArchitectureshavetheirownadvantagesanddisadvantages,so,asolutionwiththree-tierC/SandB/Shybridsoftwarearchitectureareproposed.InBEIP,theusers,suchasadministrativedepartmentsofbasiceducationandsystemadministrator,accesssystembasedonthree-tierC/Sarchitecturebecausetheyneedtoprocessdatareportandmaintainresourceswhichhavelargeamountsofdatatotransmit.ExpressinglayerbasedonGUIimplementdatainputanddisplayandcandealwithdataslightly.Businesslogiclayermainlyprovidedbytheapplicationserverrealizethemainfunctionsofthesystemandaccessthedatalayer.DataaccesslayerusingMicrosoftcooperationsSQL2005tomanageandmaintaindata.Theselayersaredeployedtodifferenthardwaresystemsseparately.Thismechanismimprovessystemperformance,maintainabilityandsafety.SystembasedonB/Sarchitectureissuitableforcommonusersaccess.Studentsstudyonline,teachersanswerthequestionsandreleasehomework,parentsbrowsetheresourcesandwriteguestbooks,theseoperationsfocusonfunctionalityandeaseofuse.Inanyplaceatalltimes,usersonlyneedacomputerconnectedtotheInternetcaneasilyaccessthesystemthroughthebrowser.ApacheStrutsisanopen-sourcewebapplicationframeworkfordevelopingJavaEEwebapplications.ItusesandextendstheJavaServletAPItoencouragedeveloperstoadoptamodel-view-controller(MVC)architecture.ItwasoriginallycreatedbyCraigMcClanahananddonatedtotheApacheFoundationinMay,2000.FormerlylocatedundertheApacheJakartaProjectandknownasJakartaStruts,itbecameatoplevelApacheprojectin2005.DesigngoalsandoverviewInastandardJavaEEwebapplication,theclientwilltypicallysubmitinformationtotheserverviaawebform.TheinformationistheneitherhandedovertoaJavaServletwhichprocessesit,interactswithadatabaseandproducesanHTML-formattedresponse,oritisgiventoaJavaServerPages(JSP)documentwhichinterminglesHTMLandJavacodetoachievethesameresult.Bothapproachesareoftenconsideredinadequateforlargeprojectsbecausetheymixapplicationlogicwithpresentationandmakemaintenancedifficult.ThegoalofStrutsistocleanlyseparatethemodel(applicationlogicthatinteractswithadatabase)fromtheview(HTMLpagespresentedtotheclient)andthecontroller(instancethatpassesinformationbetweenviewandmodel).Strutsprovidesthecontroller(aservletknownasActionServlet)andfacilitatesthewritingoftemplatesforthevieworpresentationlayer(typicallyinJSP,butXML/XSLTandVelocityarealsosupported).Thewebapplicationprogrammerisresponsibleforwritingthemodelcode,andforcreatingacentralconfigurationfilestruts-config.xmlwhichbindstogethermodel,viewandcontroller.Requestsfromtheclientaresenttothecontrollerintheformof“Actions”definedintheconfigurationfile;ifthecontrollerreceivessucharequestitcallsthecorrespondingActionclasswhichinteractswiththeapplicationspecificmodelcode.Themodelcodereturnsan“ActionForward”,astringtellingthecontrollerwhichoutputpagetosendtotheclient.InformationispassedbetweenmodelandviewintheformofspecialJavaBeans.ApowerfulcustomtaglibraryallowsittoreadandwritethecontentofthesebeansfromthepresentationlayerwithouttheneedforanyembeddedJavacode.Strutsalsosupportsi18n(internationalization),providesfacilitiesforthevalidationofdatasubmittedbywebforms,andincludesatemplatemechanismcalled“Tiles”which(forinstance)allowsthepresentationlayertobecomposedfromindependentheader,footer,andcontentcomponents.CompetingMVCframeworksAlthoughStrutsisawelldocumented,matureandpopularframeworkforbuildingfrontendstoJavaapplications,itisfacingnewchallengesfromnewer“lightweight”MVCframeworkssuchasSpringMVC,StripesandTapestry.ThenewXFormsstandardsandframeworksmayalsobeanotheroptiontobuildingcomplexwebFormvalidationswithStrutsinthefuture.TheWebWorkframeworkspunofffromApacheStrutsseveralyearsago,aimingtoofferenhancementsandrefinementswhileretainingthesamegeneralarchitectureoftheoriginalStrutsframework.However,itwasannouncedinDecember2005thatStrutswouldre-mergewithWebWork.WebWork2.2hasbeenadoptedasApacheStruts2,whichreacheditsfirstfullreleaseinFebruary2007.SunrecentlybroughtoutanewadditiontotheJavaplatform,calledJavaServerFaces(JSF).Asidefromtheoriginalframework,theApacheStrutsprojectalsooffersaJSF-basedframeworkcalledShale.OtherMVCframeworksthatarenotJ2EEbasedincludeRubyonRails,WebObjects,Django,Catalyst,TurboGears,CakePHP,Symfony(forPHP),Zend,AchievoATK,andCodeIgniter(forPHP).Struts4phpisaversionoftheStrutsframeworkforthePHPwebscriptinglanguage.GirdersisaportoftheStrutsframeworkinC#forMicrosoft.NET.Alongwiththeprogressivedevelopmentofcollegeteachingmanagementreformation,laboratoryconstructionisbecomingmorestandardandmorecomplicated,andcollegelaboratorymanagementhasbecomemoreonerousandcomplex.Inordertofacilitatetheexpansionofthemanagement,improveworkefficiency,andsimplifyourwork,computer-aidedmanagementisnecessary.Thesysteminthispaperwasdesignedanddevelopedbasedonit.ExperimentteachingmanagementsystemisasolutionbasedonPetShoparchitecture;itadopted.NETframework,thethree-tierstructure,B/SmodeandOOP;itusedSQLServer2008asadatabasemanagementtool,soitsmodulereuserateishighanditsmaintenancecostislow.Thesystemisconvenient,flexibleandefficient,anditcanachievetheinteractionamongtheteachingmanagementstaff,labadministrators,teachersandstudents.J2EEtypicalthree-tiersoructure,dividedintopresentationlayer,middlelayer(BusinessLogicTier)andthedataserviceslayer.Three-tiersystembusinessrules,dataaccessandworkoncheckingthelegitimacyofthemiddlelayer.Theclientdoesnotdirectlyinteractwiththedatabase,butbymiddle-tiercomponentsandestablishaconnection,andthenbythemiddle-tieranddatabaseinteraction.AfterTheperformanceoftheJSPlayeristhetraditionaltechnology,sinceitsinceptionin1999,yearsofdevelopment,itswiderangeofapplicationsandstableperformance,theperformanceofitstechnologyasasolidfoundation.MiddlelayerisusedinthepopularSpring+Hibernate,inordertocontroltheseparationlayerandBusinessLogicTier,isdividedintothefollowingtypesoffine.Weblayer,whichistheMVCpatternofC(controller),BusinessLogicTierisresponsibleforcontrolandperformanceoftheinteractivelayer,calledBusinessLogicTier,andoperationalperformancedatabacktotheorganizationlevelfortheperformanceofthesystemusingtheMVCframeworkStruts.ServiceLayer(BusinessLogicTieris),isresponsiblefortheachievementofbusinesslogic.BusinessLogicTierisbasedonaDAOlayer,throughthepositivecomponentsoftheDAOmodepackaging,thecompletionoftherequirementsofthesystembusinesslogic.DAOlayerisresponsibleforinteractionwiththepersistentobject.Thelayersofdatabypackage,delete,search,changetheoperation.PO,persistentobject.Throughtheentity-relationalmappingtoolforrelationaldatabasewillbemappedintothedataobject,itisconvenienttooperateinobject-orienteddatabase,thesystemusesHibernateastheORMframework.TheroleofSpringrunsthroughtheentiremiddlelayer,theWeblayer,Servicelayer,DAOlayerandseamlessintegrationofPO,thedataserviceslayerisusedtostoredata.Agoodframeworkallowsdeveloperstoreducethere-establishmentofprogramstosolvecomplexproblemsandenergyburden;itcanbeexpandedtoacustomizedinternal;andhaveastrongusercommunitytosupportit.Frameworkisusuallyagoodsolutiontoaproblem.However,yourapplicationislayered,andmayeachlayerrequiresitsownframework.OnlysolvetheUIproblemdoesnotmeanthatyoucanbegoodbusinesslogicandpersistencelogicandUIcomponentsofagoodcoupling.Thereisnodenyingthatforsimpleapplications,usingASPorPHPdevelopmentusingJ2EEframeworkmoreefficientthanthedevelopmentofhigherefficiency.Somemayeventhink:thishierarchicalstructure,thanthegeneraladoptionoftheJSP+Servletevenlowerefficiencyofsystemdevelopment.Theauthorofseveralabouttheperspectivefromonthisissue.1.Thedevelopmentofefficiency:SoftwareEngineeringisaspecialindustry,unlikethetraditionalindustries,suchaselectricalappliances,constructionandautomotiveindustries.Productsoftheseindustries,oncedeveloped,thedeliveryofveryfewuserswillneedtofollow-upmaintenance.However,differentfromthesoftwareindustry,softwareproducts,thelatterisahugeoperationandmaintenanceoftheproject,purelyfromthepre-developmenttimetoconsidertheefficiencyofitsdevelopmentisnotrational,butalsounfair.Asweallknow,thetraditional,suchasASPandPHPscriptssitetechnologytoawholesitebusinesslogicandtheperformanceoflogicmixedwithASPorPHPpages,resultinginverypoorreadabilityofthepage,verylowmaintenance.Eveniftheneedforasimplebuttontochangethepage,thepagehadnochoicebuttoopenthefile,runtheriskofdamagetothesystem.However,thestricthierarchicalstructureofJ2EE,youcancompletelyavoidthisproblem.Ontheperformanceofthemodifiedlayer,evenifanerroroccurs,theerrorwillnotbeextendedtotheBusinessLogicTier,butwillnotaffectthepersistencelayer.Therefore,theuseofJ2EElayeredarchitecture,evenifthepre-developmentefficiencyslightlylower,butitisalsoworthwhile.2.Thedemandforchange:totheauthormanyyearsofdevelopmentexperience,veryfewsoftwareproductsfromtheoutset,isfixed.Customerdemandforsoftware,softwaredevelopmentprocesswithin-depth,constantlyclearup.Therefore,oftenencounteredinsoftwaredevelopmenttoacertainextent,duetocustomerdemandforsoftwarehaschanged,makingtherealizationofthesoftwarehadtochange.Whenthesoftwareneedstochange,itcanretainasmuchaspossiblepartofthesoftware,changeaslittleaspossibletherealizationofsoftwaretomeetchangesincustomerneeds?Theansweris-theuseofthedecouplingofoutstandingarchitecture.ThisarchitectureisalayeredJ2EEframework,layeredarchitectureinthebest,thecontrollayerdependsonBusinessLogicTier,butnotwithanyspecificbusinesslogiccomponentcoupling,onlycouplingwiththeinterface;Similarly,theBusinessLogicTier-dependentintheDAOlayer,butalsowillnothaveanyspecificDAOcomponentcoupling,butorientedprogramminginterface.Theuseofthesoftwareinthisway,evenifsomesoftwarechanges,otherpartsdonotchangeasmuchaspossible.Note:Eveninthetraditionalhardwarebusiness,therearealargenumberofinterfacespecification.Forexample,PCIinterface,graphicsornetworkcard,aslongastheycomplywiththePCIspecifications,youcaninsertthemotherboard,andmotherboardcommunications.Asfortherealizationofthisinternalcardisnotofconcerntothemotherboard,whichistheprogramminginterfaceforthebenefits.Iftheneedtoimprovecomputerperformance,theneedtoupdatethegraphics,aslongasthereplacementoftheotherPCIinterfacecard,ratherthanabandonthewholecomputer.Ifacomputerisnotcombinedwithavarietyofinterfaces,buttheentirecause,itwouldmeanthateveniftheonlyneedtoupdatethecard,butalsotogiveupthewholecomputer.Similarly,forasoftwarecomponent,asacomponentoftheneedforreconstructionasfaraspossible,willnotaffectothercomponents.Infact,thisisthebest,eventhebestofthecurrentstructure,willbeaffectedtoacertainextent,thisisalsotheneedtostrivetoimprovethesoftwareengineeringarea.Technologyupdates,systemreconstruction:technicalupdatethesoftwareindustryverysoon,althoughthedevelopmentofthesoftwareindustryunpleasant,butsmall-scaletechnologyupdateparticularlyfast.Oncethechangesasaresultofobjectivecircumstances,hadtoreplacethetechnology,howtoensurethatthesmallestchangeinthissystem?Theansweristochoosethebeststructure.Model1inthetraditionalstructureoftheprogram,aslongasthereislittlechangeindemand,wouldmeangivinguptheentirepage.Orrewritten.Althoughtheearlydevelopmentofspeed,unlessitcanbeguaranteedtoneverchangethestructureoftheapplication,ornottoadoptthestructureofModel1.TheuseofHibernateasapersistencelayertechnologyisthebiggestadvantage:Youcancompletelyobject-orientedapproachtosystemanalysis,systemdesign.DAOpatternforeachDAOinterfaceDAOcomponentsprepared,atleastatthesametimeprovideanimplementationclass,accordingtothedifferentneeds,theremaybeanumberofimplementationclass.SpringcontainerusingthefactoryinsteadofDAO.Undernormalcircumstances,theintroductionofinterfacewillinevitablyneedtoberesponsiblefortheintroductionofthefactorytogenerateDAOcomponents.Springhastwobasicmodes:single-statemodelandthefactorymodel.Springcanbeusedtoavoidtheuseofthefactorymodel,becauseSpringisaverypowerfulplant.Therefore,SpringcanserveasaDAOfactory.DAOfromSpringtoserveasfactories,thefactoriesdonotneedprogrammerstoachievetheirownmodel,onlyneedtoconfiguretheDAOcomponentsintheSpringcontainer,bytheApplicationContextcomponentsresponsibleforthemanagementofDAOcancreate.WithSpringsdependencyinjectiontoprovidetheothercomponentsdonotevenvisitthefactories,asexamplesofdirectaccesstoDAO.Advantages:StrutswithTomcat,Turbine,andmanyotherApacheprojects,areopen-sourcesoftware,whichisamajoradvantageofit.Allowdeveloperstomorein-depthunderstandingoftheachievementofitsinternalmechanism.Inaddition,Strutsfocusedmainlyonthemeritsintwoaspects:Taglibandpagenavigation.TaglibistheStrutstaglibrary,aflexibleuse,cangreatlyincreasedevelopmentefficiency.Inaddition,thecurrentdeveloperoftheJSP,withtheexceptionoftheuseofcommonlyusedbuilt-inJSPtag,veryfewmarkerstodeveloptheirown,perhapsofStrutsisagoodstartingpoint.Onpagenavigation,Ithinkitwouldbeadevelopmentdirectionforthefuture,infact,todoso,makethesystemmoreclearlythecontext.Throughaconfigurationfile,youcangraspthewholesystemlinksbetweenthevariousparts,whichthelatterhasanimmenseamountofgoodmaintenance.Especiallywhenanothergroupofdeveloperstotakeovertheproject,thisreflectedamoreobviousadvantage.Disadvantages:TaglibisoneofthemajoradvantagesofStruts,butforabeginnerrun,itrequiresacontinuouslearningprocess,andmayevendisruptthehabitofpreparingyourwebsite,butwhenyougetusedtoit,youwillfinditreallyrods.StrutswillbeaControlleroftheMVCisdividedintothree,inobtainingamoreclearstructure,butalsoincreasethecomplexityofthesystem.中文翻译如今，电子商务（EC）起着举足轻重的作用，在网上，涉及不同的方面（即技术，经济，法律等），根据欧共体交易（Palopoli等，2006）的特点。特别是，商家与客户之间的交易乳油通常表示为商家对客户（B2C）的过程中，可以比传统的商业零售业。更具体而言，B2C市场涉及大量的兴趣通过使用一个方便的媒体和客户的购买欲的产品，提供产品的商家。在这种情况下，客户和商家可以利用不同的机会（2003Zwass）为：（1）没有时间和空间的界限;（2）简单性，效率和销售及采购的舒适性;（3）具备成本低和几个销售条款。然而，一个显著客户商家的不信任（西亚斯-Pradas等2013）仍然存在于欧盟，主要是由于缺乏个人接触和接受程度较低的电子支付方式出于安全原因。一个B2C的交易是由不同的活动，例如搜索一个产品，选择一个商人，谈判最优惠的价格等，而必须进行的客户和商家的一个复杂的决策过程。在此情况下，相关注意一直致力于识别顾客的行为和互补的商家的行为。几个研究已经在文献中提出以模型构成一个B2C过程的不同阶段。其中有些是由传统零售商业推导尼科西亚（尼科西亚1966）或恩格尔和Blackwell（恩格尔等人，1995）的模型，而另一些对Web经过特别设计，为尼森的商业模式（1997尼森）中，电子商务的价值链模型（费尔德曼1999）或相关西蒙的决策过程，通常在决策支持系统中使用（Miles和豪斯2000）。作为控制软件复杂性的最重要的手段之一，提高软件系统的质量和支持软件开发的复用性，软件架构已经得到越来越多的研究人员和开发的关注。今天，软件体系结构已经成