2023学年完整公开课版CUHKRFIDMiddlewareSystem（2022新）4

Presenter:MiZhiqiangHunanModernLogisticsCollegeRFIDMiddleware-System8ProcessView8.1ApplicationtoMiddlewareInterfacesUpperlevelapplicationscanaccessthemiddlewarethroughtheSOAPinterfaces.Therearetwomainsetsofinterfaces:theALEstandardserviceinterfacesandtheCUHKtagdataservicesinterfaces.TheSOAPinterfacesuseHTTPasthetransportprotocol.Tofacilitateapplicationintegration,theinterfacescomewithwSDLdefinitions,whichareXML-baseddescriptionsforwebservicesdefinedaccordingtow3cwSDLstandard(http:/TR/wsdl).ApplicationclientscanreadtheWSDLtodeterminewhatfunctionsareavailableontheserver.TheclientscanthenuseSOAPtoactuallycalloneofthefunctionslistedintheWSDL.TheWSDLcontains4majorsections:1.wsdl:messages-representsthedatabeingtransmitted;allrequestandresponseobjectaredefinedhere.2.wsdl:portType-representsalltheoperations,andeachoperationreferstoaninputandoutputmessage.3.wsdl:binding-specifiestheprotocolsanddataformatsfortheoperationsandmessages.4.wsdl:service-definesthecommunicationendpoints.8.1.1ALEServiceInterfacesThesearethestandardinterfacesofthemiddlewareasdefinedinALEspecificationsection8.1.TheserversideoftheinterfacesisimplementedbytheALEServiceEJBcomponent.Oncetheserverisstarted,theWSDLcanbeaccessedvia:

http://eservername>:8080/ale-ws/aleservice?wsdlThefollowingoperationsaresupported:define(specName:string,spec:ECSpec):voidundefined(specName:string):voidgetEcSpec(specName:string):ECSpecgetECSpecNames(:Listsubscribe(specName:string,notificationURI:string):voidunsubscribe(specName:string,notificationURI:string):voidpoll(specName:string):ECReportsgetSubscribers(specName:String):ListgetStandardVersion():stringimmediate(spec:ECSpec):ECReportsgetvendorVersion(:stringThedetailsoftheoperationcanbefoundinALEspecificationSection.2TagDataServiceInterfacesTheseareCUHK‘sextensionstothemiddlewarestandardinterfacestosupporttagdatareadsandwrites.TheserversideoftheinterfacesisimplementedbytheTagDataServiceEJBcomponent.Oncetheserverisstarted,thewSDLcanbeaccessedvia:

http://<server_name>:8080/ale-ws/aletagdata?wsdlThefollowingoperationsaresupported:-readData(data:DataSpec):byte[]-writeData(data:DataSpec):intDataSpecisthekeytosupporttagdataservices.DataSpecisadatastructurewhichcontainstagid,formatid,dataaddress,datalength,anddatabytes.Theformatidisanintegerdictatingtheaddressingschemetobeused.Thevalueof0representsbyteaddressing,whichisthesimplestaddressingschemethateverybytehasitsownaddress.Thevalueof1representspageaddressing,whichthedatamemoryisaddressablebyusingpagenumber,andreadsandwritesalwaysstartfromapage.byte[]readData(DataSpecdata)Basedonthedata(DataSpec),thefunctiongetsalistofreaderidswhichhasreadthetagidwithinapredefinedtimeperiod(defaultis10s).Withthereaderidlist,theserveractivatesallthereadersbysendingthereadtagcommandtothereaders,forthatparticularreadid,anddataaddress,datalength,andformatid.Thefirstreaderrepliedtothequeryisconsideredasatagreadhit,writeData(DataSpecdata)Thewrite-into-tagoperationcanbetimeconsumingandunreliable.Therefore,weseparatetherequestandresponseintwoasynchronousmessages.TheapplicationuserstartsbyissuingwriteDatafunctioncallviaSOAP.TagDataServiceBeanthentakesthisrequest,anditwilllocatetherelatedreadersviaTagDataServiceDAOImpl.TagDataServiceBeanwilllocatethelistofreaders,andgenerateaGUID(globaluniqueidentifier)forthisparticularrequest.WiththeGUID,TagDataServiceBeanregistersforacallback,TagDataServiceCallback.LaterReaderManagerBeanwillusethiscallbacktonotifythewrite-into-tagresult.Atthesametime,TagDataServiceBeansendtheTagWriteActivateRequesttoaninternalqueuingmodule,whichwillasynchronouslysendthewrite-into-tagrequesttogetherwithGUIDtoallreaderadaptors.Onceatagwriteissuccessful,thereaderadaptorwillsendaresponsewiththeGUIDtoReaderManagerBean,whichinturnswillusethepredefinedcallbackcorrespondingtotheGUID.TagDataServiceBeanwillbenotified,andreturntheresulttothefunctioncallee.Returns0:success1:otherfailures2:noreadersaccesstothetag8.2MiddlewaretoApplicationInterfacesThecommunicationfrommiddlewaretotheapplicationfollowsthestandardnotificationmechanisms,asdescribedintheSection9ofALEspecification.ThemiddlewaresupportstheHTTP,TCPandFILEnotifications.8.3AdaptortoMiddlewarelnterfacesThesearetheinterfacesbetweentheReaderAdaptorandtheReaderManagercomponentinthemiddleware.TheReaderManagerisimplementedasastatelesssessionbeanusingEJB.TheReaderAdaptorshouldbeimplementedasanEJBclientusingtheexportedlibraryadaptor-client.jar.TheprotocolinbetweenisRMI/JRMP.Thefollowingmethodsaredefined.publicvoidsubmitALEPhysicalReaderinfo(StringreaderlD,PhysicalReaderinfophysicalReaderlnfo)throwsExceptionTheadaptorusesthismethodtosubmittotheALEtheconnectedhardwarereader‘sinformation.SincethephysicalreadermustbedefinedintheALEbeforetheadaptorcansubmittagstoALE,theadaptorshouldcallthismethodtodoreaderregistrationonthefirsttimeconnectingtotheserver.ThismethodcanbealsobeusedtoupdatethereaderinformationintheALE,bydoinganothersubmissiontoanalready-definedreader.ThePhysicalReaderInfoisaclasswiththefollowingattributes:manufacturer,modelandIPaddress.publicvoidsubmitALETags(StringreaderlD,List<String>tags)throwsExceptionThisadaptorusesthismethodtosubmitthetagsreadineveryreadcycletoALE.TheReaderAdaptorshouldcallthismethodregularly(i.e.ataparticularfrequency)tosubmittagstotheserver.Inareadcycle,thetagssubmittedshouldbedistinctwithoutduplicatesandinthe"TagURl"formatdefinedEPCGlobalTagDataSpecification(e.g."urn:epc.tag:gid-96:21.300.1").AnexceptionwouldbethrownifthereaderIDisnotyetdefinedintheALE.publicvoidsubmitReadData(StringreaderlD,intstatus,byte[]data,Stringguid)Thisadaptorusesthismethodtosubmitthetagdatathatthereaderhasbeenrequestedtoread.Inatag-readcycle,commmandsaresenttoreaderfrormmiddlewaretoreadtagdatastoredinaparticulartaginaparticularreader.Sincethecommandisanasynchronouscall,thesubmitReadDatamethodisusedasacallbackforthereaderadaptortocommunicatewiththemiddlewareforthedataread.publicvoidsubmitWriteData(StringreaderlD,intstatus,Stringguid)Thisadaptorusesthismethodtosubmitthetag-data-writestatusthatthereaderhasbeenrequestedtowrite.Inatag-writecycle,commandsaresenttoreaderfrommiddlewaretowritetagdatatoinaparticulartaginaparticularreader.Sincethecommandisanasynchronouscall,thesubmitWriteDatamethodisusedasacallbackforthereaderadaptortocommunicatewiththemiddlewareforthestatusofthetag-write.8.4MiddlewaretoAdaptorInterfacespublicvoidread(StringreaderID,StringtaglD,DataSpecspec,Stringguid)throwsRemoteExceptionThemiddlewareusesthismethodtor