基于的多媒体资源管理系统doc.docx
《基于的多媒体资源管理系统doc.docx》由会员分享,可在线阅读,更多相关《基于的多媒体资源管理系统doc.docx(7页珍藏版)》请在冰豆网上搜索。
基于的多媒体资源管理系统doc
基于SOA的多媒体资源管理系统7
ASOA-basedGeneralMultimediaResourceManagement
System1
WangJiayu
BeijingKeyLaboratoryofIntelligentTelecommunicationSoftwareandMultimedia,BeijingUniversityofPostsandTelecommunications,Beijing(100876)
E-mail:
wangjy@
Abstract
Inthecurrentcomputerapplication,buildingageneralmultimediaresourcesmanagementsystemtodevelopthepotentialofexistentsimilarmanagementsystemisahotspot.Thispaperwillfirstanalyzethedevelopmentofthecurrentmultimediaresourcesmanagementsystem.ThenrelyingonSOAandmiddlewareframework,weimprovethecurrentmultimediamanagementmodeltoachievethegoalsofmanagementoptimizationandsystemintegration:
openness,flexibility,simplicity,scalability.Secondly,wedesignasystembasedofthemodel.Finally,wedevelopanexampletoprovethatthemodelisagoodevidenceofthemultimediainformationmanagementwithhighpracticalvalue.
Keywords:
SOA,Middleware,MultimediaResourceManagement
1Introduction
Withthedevelopmentofnetworktechnologyandapplications,thequantityandtypesofmultimediaresourcesgrowthrapidly.Theareaofmultimediatechnologywillbecomelargerandthenumberofpracticalsystemswillincreaseeveryyear.Obviously,theresourcesinformationwillbeasignificantgrowth.Therefore,itisimportanttomanagetheinformationefficiently[4].Buttheexistingmultimediamateriallibrariesoftenlackofthedescriptiveinformationaboutmultimediaresources.Theorganizationandmanagementformultimediaresourcesareunsatisfactory.Andtheeffortsaboutsearchingmultimediaresourcesarenotenough.Thosearealldifficulttosatisfyapplicationrequirements.Fortheabovedemand,weneedaneffectivemultimediaresourcesmanagementsystemwhichcanprovideafriendlyuserinterface,themorerichapplicationservices,andcanbuildthesystembyscalabilityandversatility.
TheusingofSOAwilltakeweachievethesystem.Service-orientedarchitectureisanindependentfunctionalentitywhichcompletesspecifictasksbyconnectingtosolvetheneedsofbusinessininternetenvironment[6].SOAisabletomaketheresponsibilitiesofvariousfunctionsmoreclearlyinawholesystem.Italsocanshortenthedevelopmentcycleandreducemaintenancetimetohaveamoreefficientwaysofutilizingresources.Meanwhile,wewillusemiddlewaretechnologywhichcanshieldthecomplexityofapplicationinunderlyingoperatingsystem.Sodeveloperswillfaceasimpleandunifieddevelopmentenvironmentwhichcanreducethecomplexityofthedesignprocess.Andtheywillfocusattentionontheprovisionoftheirserviceswithoutreiterationworkingindifferentsoftwaresystems.Thusmiddlewarecangreatlyreducethetechnicalburden.Weadopttheframeworkandtechnologytoperfecttheexistingmanagementsystemtomanagethemultimediamaterialmoreeffectively.
Theotherpartofthispaperisarrangedasfollow:
inthesecondchapterwewilldiscussandanalyzeexistingmultimediaresourcesmanagementsystem;inthethirdchapter,wewillgiveasystemmodelanditsarchitecture;thenextchapter,wewilluseanexampletoexplainoursystems;finally,wesummarizethepaper.
1ThisworkreportedinthispaperissupportedbytheSpecializedResearchFundfortheDoctoralProgaramofHigherEducationunderGrantNo.200*********andSpecialItemsFundofBeijingMunicipalCommissionofEducation(ItemNo.SYS100130422).
2RelatedWorks
Currently,theexistingmultimediaresourcesmanagementsystemscommonlyusethismodelasfollowing.Forexample,theDigital-Item-BasedMediaManagementSystem[3]byRichardJ.Qianisthetypicalmodel.Thesebasicdesignsofthestructurearesimilar.
ThesystemcanbesummedupwithafigureasFigure1.
Figure1systemstructure
Althoughfromtheirindividualperspective,suchsystems’operability,flexibility,richnessoftheirfunctionsandscalabilitycanberealizedbetter.Butwejudgeasystemnotonlyfromtheircapabilitiesandperformanceconsiderations,butalsofromtheroleintheentireapplicationenvironment.Fromthisperspective,wewillfindinadequatewhenthesystemintheactualoperation:
First,redundantdataofmultimediaresourcesandtheirrecordsmaybeproducedwhenthesystemoperating.Itwillmakesystem’sconsistencydeteriorate.
Secondly,thefunctionsareredundant.Althoughsomeofthesystem’sfunctionsmaybedissimilar,wefindthattherearealsocommoncodesandresourcesintheirsubsystemswhenwedecomposethemultimediamanagesystem.Ifwedevelopanewmediafunctionwithrebuildingallcodes,wewillwastelongertimeandmoreresources.
Third,itisdifficulttodevelopanewsystembyusingtheoldone.Inpracticalapplicationenvironment,reusingofmultimediaresourcesisextremelydifficultbecauseofthedifferencesofdevelopmenttools,actualoperatingenvironmentsandsystemarchitectures.Wehavetoreadlotsofcodesanddesigndocumentstobefamiliarwithitsinternalstructure.Itmeansthatworkloadofreusingisnotlessthanrebuilding.Further,ifthefunctionbeeliminatedoneday,itwouldcausetroubletooursystem.
Atthemoment,wesolvetheproblemsbyintroducingtheconceptofSOAandmiddlewaretechnology.Aconcreteexplanationwillbeexplainedinthenextchapter.
3Architecture
Basedonpreviousresearchandanalysis,weattemptedtousemiddlewareandSOAtoimprovethestructureoftheoriginalmodel,andeventuallygivenaconcreterealizationofthemodel.
3.1.1DesignPrinciplesandDesignObjectives
Thedesignprinciplesandaimsareshowedasfollows:
(1)First,thesystemwillbeusedforgeneralmultimediaresourcesmanagement.Sowehopethatthelinkbetweendifferentapplicationcomponents’interfaceandtheirfunctionsorstructuresisloosetoensuretheirflexibility.Andtheycancontinuetoexistwheneachservice'sinternalstructureintheentireapplicationprocesschanged.[8]
WeadopttheSOA.Itisacomponentmodel[2]withapurposeofcommonusingandscalability.Itisajointcollaborativeframework.Itdefinesallprocessesasservicesandlinksdifferentfunctionalunits(calledservices)throughinterfacesandconventionswhichdefinedwellbetweenservices.Interfacesaredefinedneutrality;itindependentfromhardwareplatforms,operatingsystemsandprogramminglanguagestoensurethatservicesinthesysteminteractbyaunifiedandcommonway.WhiletheSOA-basedsystemdoesnotexcludeusinganobject-orienteddesigntobuildasingleservice,itsoveralldesignisaservice-oriented[5].Thedifferenceistheinterfacesthemselvesasfollow[1]:
a.Allfunctionsaredefinedasservicesincludingbusinessfunctions,businessservicesandsystemsservicesfunctionswhicharecomposedfromthebottomfunctions.
b.Allservicesareindependent.Theyrunasthe"blackbox":
externalcomponentsneitherknownorconcernabouthowtoexecutethefunctions,butonlycareaboutwhetherornotreturningthedesiredresults.
c.Inthegeneralsense,theinterfaceisavailable;Inotherwords,fromthearchitecturelevel,wedon’tcareaboutwhethertheyarelocal(withinthesystem)orremotely(beyondthedirectsystems),andwhatkindofprotocoltocallorwhatkindofstructuretoconnect.
Therefore,weusedtheSOAtomaintaintheirlooselycoupledbetweenapplications;
(2)Naturally,weexpectapplicationdevelopersfacingasimpleandunifieddevelopmentenvironment.Itwillreducethecomplexityoftheprocesstofocusdevelopers’attentiononwhatservicestheyprovide,withoutduplicateworkintransplantbetweendifferentsoftwaresystems.Thiswillgreatlyreducetheburdenonthetechnical.Middlewarecancomplywiththerequirements.[8]Middlewareasanspeciallevelbetweenthesystemsoftwareandapplicationisabstractedasatypicalapplicationmodel,sothatsoftwaremakerscanfocusonbusinesslogic,andcandevelopbyastandards-basedformway.Itmakesthesoftwarearchitecturebecomepossibly.Someindustrystandardstakemiddlewareastheoperatingframeworkofreusablecomponentstoacceleratepracticalprocessofsoftwarereusing.
Essentially,middlewareisanabstractionofdistributedapplication[7].Thusitabandonsthedetailsofbusinesslogicrelatedbyapplication,whileretainsthekeyfeaturesofthetypicaldistributeinteractivepattern.Throughtheabstracting,acomplexdistributedsystemisrefinedtoaunifiedformandshowstotheapplication.Applicationcanbeintegratedbetterwiththeenvironmentprovidedbymiddlewareintothebusinesslogic,andexistsastheformofcomponents.Finally,itcannaturallyachieveagoodeffectinaheterogeneousenvironment.
Itappearsthatusingthemiddlewaretechnologytoachieveoursystemisnotonlytosimplifythedevelopment,toshortenthedevelopmentcycleandtoreducetheworkloadofsystem'smaintenance,operationandmanagement,butalsoreducethecostofthewholeenvironment.
Therefore,wewillusemiddlewarewhichtakegreatpartinoverallplatformandtoresolvecommunicationbetweeneachapplication;
(3)Atthesametime,wewillprovidethemanagementandsecurityservicestoimprovethesystem.
Basedontheaboveprinciple,wedesignthehierarchicalmodelasfigure2:
Figure2hierarchicalmodel
FromFigure2,wecanseethatafterusingthemiddlewareplatform,eachapplicationcommunicatesthroughtheplatforminsteadofdirectlyinteraction.Thismakesthecallingapplication’slevelmoreclearly;meanwhile,newapplicationscanbebuiltonthemiddlewareplatformbyusingalotofservicesthroughthemiddlewareplatform;thenewservicewillbemoreconvenienttojoin,andtheexistingsystemwillnothaveanyimpact.Interfacesbetweenoriginalsystemandtheusershavenotch