Luận văn Nghiên cứu và xây dựng một số ứng dụng dựa trên mobile agent

CHUaNG 2 PHAN TicH HE THONG MOBILE AGENT. . H~th6ngmobileagentbaag6mhaithanhph§nchinhdola cacmobile agentvamoitntangh6trQvi~cthihanhchung,t~mgQiIa moiWongthi hanh.MQtmoitntangthihanhc§nphiiiGaplingcacyellc§usail: .:. Qwin11vah6trQvi~cthihanhcuacacmobileagent,chophepnhi~u agentclingt6nt~iva thihanhd6ngthai,clingca'pcacdichV\l troy C?Pdentainguyencuah~th6ng. .:.H6 trQchoHnhdi dQngcuacacmobileagent:chophepdungcac mobileagentdangtht!chi~nvagii'inodenmoiWongthihanhkhac, clingnhu'nh?nv~vachophepthihanhtrdl~icacmobileagentden tumoitntangthihanhkhac. .:.H6 trQchovi~clien l~cva traod6i giii'acacagent:chophepcac agentgii'idi vanh?nv~cacthongdi~ptucacagentkhac,... .:.Baodamantoanchocacagenttrongmoi Wong clingnhu'cactai nguyencuah~th6ng. I. MOBILE AGENT vA MOl TRUONG THI HANH 1.Mobileagent Mobileagentla mQtht!cth€ conamthuQcHnh: tr~ngthai,matillhanh, giaodi~n,dinhdaub,vacacthanchu(ngu'aiuyquy~n).Khi mQtagentdi chuy€ntrenm~ngno semangtheocacthuQcHnhnay. 20 .:.TrlJ-ngthai:c~nchoagenttht!chi~nITahilicacthaolac sankhi di chuy6n. .:.Mil caidijt:c~nchocacagentthih~lllhdQcl~pvdi vi trL .:.Giaodi?n:c~nchost!lien lc;lCgiii'acacagent. .:.Dinh danh:c~nchovi~cnh~ndi~nva dinhvi cac agentkhi di chuy6n. .:.Thanchit:c~nchovi~cxac dinhquy~ntroyc~pva sa d\lngtai nguyen. Cae thanehu Giaodi$n Me eaidQt TrQngthai Dinhdanh Hinh2.1- Cac thuQctfnhcua mobileagent 1.1.Tr(lngthai KhimQtagentdi chuy6n,no c~nphaimangtheotrc;lngthaicuano di cling.Dayla d~cdi6mcuah~uhe'ta'tcacacmobileagentd6coth6tie'n hfmhtht/chi~nlc;licacthaolacamaydfch. Trc;lngthaicua agenttc;liba'tki thai di~mnao la mQtth6 hi~ncua qua trinhthihanhcua no. D6i vdi h~uhe'tngonfigii'l~ptrinhchungta co th6 chiatrc;lngthaicuaagentthanhtrc;lngthai thi hanhva trc;lngthaid6i tu'<;1ng. 21 Tr~ngthaithihanhg6mcacbQde'mchu'dngtrInh,tlOOtr~ngnganxe'p; tr~ngthaid6itu'Qng6mgiatricuacacbie'nth~hi~ntrongd6itu'Qng. 1.2.Mil cai dij,t Gi6ngOOu'b§t kl chu'dngtrlOOmaytiOOnaokhac,mQtmobileagentcffn phaico madS thi hanh.Khi di chuySn,no co th~l1.fachQnho~cla mang theomathihanh,ho~cla de'nmaydkhr6ixemdacomathihanht~ido chu'a,ne'uchu'athltiii cacmaconthie'uv~. Ma cuaagentphaivuacothSthlfChi~ndu'Qct~imaydkh vaphaivua anloanchomaynaykhi thihaOO.Cac ngonngii'thongdichva kichban hi~nnaynhu'Java du'ara mQtcd che'an loan, chopheph~nche'vi~ctruy c~pWi cactai nguyendaOOrieng cua may.Di~u nay th1.fchi~ndu'Qcdo m6itru'ongthihaOOdQcl~pvoi h~n~nclingOOu'du'QckiSmsoarch~tche. 1.3.Giaodifn £>Scaeagentvacach~th6ngkhactu'dnglacvoi no,agentcffnphaico m<)tgiaodi~n.Day la cacphu'dngthlicchophepcacagentva caclingd1;lng khactroyc~pde'nagenthaychophepcacagentlienl~cad~ng"ngonngii' agent"OOu'laKQML (KnowledgeQueryandManipulationLanguage). KQML la mQtngonngii'chovi~clienl~cgiii'acacagent.KQML du'ara nhi~ukiSuthongdi~p.CackiSuthongdi~pnayco thSgiupdo cacagent xii'11cacyellcffucuachung.KQML vacuphapclingnhu'ngii'nghIacuano t6nt~iamuctrencdsah~tffnglien l~cgiii'acacagent. 22 1.4.Binh danh MQiagentco mQtdinhdanhduynha'trongsu6tthaigians6ngcuano. Cacagentcftnco cacdinhdanhd€ chungco th€ dll'Qcnh~nbi€t va dll'QC dinhvi quacac dichVl;l,VI dl;lnhll'dichVl;lthll'ml;lc.MQtdinhdanhco th€ duQcke'thQptudinhdanhcuathanchuva mQtmasO'.Bdi VI cacdinhdanh cuaagent1aduy nha'txet trenloan cl;lCva kh6ngth€ thayd6i, lien no co th€ duQcdungnhll'1amQtkhoatrongcac thaolac doi hoi thamchi€u Wi ffi(>tth€ hi~nCl;lth€ agent. 1.5.Caethanehil Thanchu1athl!Cth€ mamanh~nd(;lngcua no dll'Qcdungd€ xac nh~n cacquy~nh(;lnkhi agentmuontroyc~Ptoi ba'tcu h~thongnaG.Than chu coth€ 1affiQtca nhan,mQtt6 chuc,haymQtc6ngty, ...Ma nh~nd(;lngbaa g6mtenva cacthuQctfnhco th€ khac.E>6ivoi cac agentta tha'yno co It nha'thaithanchu: .:.TaeKia: ngll'aiclingca'pcaid~tagent. .:.Chilsdhilu:ngll'aicotrachnhi~mphap19vad(;loducchocachanh . ? VIcua agent. 2.M6itnidngthihanh fHychinh1andimaagent6nt(;litrongsu6tchuki s6ngcuano.No cling coth€duqcxemnhll'ladi€m VaGchocacagent"khach"(cacagentd€n tu cacmaykhac)mu6nthihanh.M6i tru'angthihanhclingca'pt~pcacdichVl;l gi6ngnhaud€ agentco th€ dlfatrendo mathihanhba'tk€ no d dau.Ta co 23 th€ xemmoitru'ongthihaOO0011Ia "h~di~uhaOO"choagent.B6n khai ni~msaildongvai troquailtrQngtrongcacmoi tru'ongthihanh: .:.Bl)ngcd:mayaoph\lcV\lchome>thaynhi~umoitru'ongthihaOO. .:.Caengudn(cdnguyen:cac cd sd dii' li~u,be>xu 11,va cac dich V\l khacd11<;1cclingcftpbdimaydo. .:.Vi tri: diachim<;lngcuamoitru'ongthihaOO. .:.Caethanchu: th1/cth~chill trachOOi~mphap11chocacthaolac cua moitru'ongthihanh. 2.1.Bl)ngcd Caemoitr11ongkhongth~t1/nothihanhcacagent.D~lamdi~udo,cac agentphait6nttde>ngcd.De>ngcdnaydingclingcftpchocac moitntongthihanhva cacagentOOunglien kC"tdi dng m<;lngnamd11diva caetainguyenkhac ma may do cling cftp.Trong mo hlnhnay, de>ngcd mangy nghiala la me>tth1/cth~v~t11hdnme>tkhai ni~mlogic.Trongh~ th6ngmobileagentd1/atrenJava, de>ngcd co th~d6ngnhfttvdi may ao Java(JavaVirtualMachine- JVM) vah~di~uhanh. MQtmaytfnhtrongmngcd,m6i de>ngcd co th€ quail11OOi~umoi tru'ongtill haOO,va m6i moi tru'ongthi haOOco th~ qmlnIf nhi~uagent.Do me>tde>ngcdco th~chuaOOi~uhdnme>tmoi tru'ong tillhanhnendoihoi cacmoitru'ongthihanhphaico tenduynhftttrongme>t dQnged. 24 Trongm9ts6h~th6ngmobileagentco thekhongco khaini~mmoi tntongthih~lllhr(;lchroi.Trongnhii'ngh~th6ngnhu'v~y,co thexemchfnh caed9ngcd Ia m9td(;lngmoitru'ongtill hanh. Maytinh Tai nguyen MoitrLlang thihanh Hlnh2.2- M6i lienh$ giGam6itrLlangthihanhva dQnged Cae dQng ed Cae m6i trLlang thihanh CaeAgent Hlnh2.3- M6hlnhella m6itrLlangthihanhagent 2.2.Caengudntid nguyen D9ngcdvamoitru'ongthihanhclingca'pvi~ctroyc~p(coIdemsoat) toicactainguyenvadichVl;!Cl;!Cb9nhu'la caccdsCJdii'li~u,cacb9xi't11 vab9 nho,cac<5ilia,va cacdichVl;!phftnclingclingnhu'phftnm~mkhac. 25 2.3.Vitri Vi tr!la mQtkhaini~mquailtrQngdO'ivoimobileagent.Vi trfcuamQt agentla st!ke'th<;1pgiuatenmoitntongmanothihanhtrongdovadiachi m(;lngcuadQngcd matrongdo moi truongthi hanht6nt~i.Vi trf nay thu'ongdU<;1cvie'tduoid(;lngmQtdiachiIP ke'th<;1pvoimQtportcuadQngcd vavditencuamoitru'ongthihanh. 2.4.Caethanchit ClinggiO'ngnhuagent,m6itru'ongthihanhclingcohaithanchu,dola : ngu'oiclingca'pcaid~t,vanguoidieuhanhm6itrUong. " " ?? II. CAC THAO TAC c(j BAN CUA MOBILE AGENT 1.1Qova hUymQtmobileagent Haithaolaccdbannha'trongchukl sO'ngcuamobileagentdola t(;lOra vabuybono. MobileagentdU<;1ct(;loratrongmQtm6i tntongthihanhnaGdo.Vi~ct~o naycoth~dU<;1cyell cftuho~cbdi mQtagentn~mtrongclingm6i tru'ongthi hanhho~cbdi mQtagentkhac.Nguoi t~ophai dU<;1cmoi tntongxac nh?n chophep,d6ngthai thie'tI?p cac quyenva cac nhi~mV\l du<;1cuy quyen maagentmoisexii'lf.Nguoit~oding co th~clingca'pcacthallisO'khdi dQngchoagent.CacdinhnghlalOpcftnchovi~ckhdit~oagentcoth~co trenmayC\lCbQhaymayd xa,hayne'ucftn,co th~du<;1cclingca'pbdi ngu'oit~o.Vi~ct~obaag6mbabuoc: 26 .:.Hifn th1/ccacdol tli(1ngvagandinhdanh:cacdli d~tcuaWpd6i tuQngduQcnt;lpva thihanh,d6itu'QngagentduQckhditt;lo.Lop d6i tuQngagentdinhnghlacagiaotie'pvacaid~tcuaagent.Saildo,moi tru'angthihanhsegallchoagentmQtdinhdanhduynha't. .:. Khdi tq.o:agentduQcpheptlfkhdi tt;lObiingcachsad1;lngcacthams6 khdi dQngduQcclingca'pbdi nguaitt;lo.Chi khi naGvi~ckhdi tt;lOdff duQchoanthanh,agentmoiduQcxemnhula t6ntt;li. .:. Thi hanh t1/trj: sail khi duQcxemla t6ntt;li,agentbat dftuvi~cthi hanhcuano.Gia daynocokhaDangthihanhdQCl~pvoi cacagent khactrongclingmoitru'angthihanh. Hftuhe'tcacagentbi buytrongmQtmoitru'angthihanhnaGdo.Vi~c buyco th~duQckhdixuongbdichfnhno haybdi agentkhacniimtrong cungmoitru'angthihanh.MQtagentclingco th~bi buybdih~th6ngVI mQt trongcac 11do sail : .:. He'tthaigiancuachuki s6ng. .:. Khongconsadl;lngVIkhongai thamchie'ude'nhaysad1;lngagent. .:. Xam pht;lmslfantOaD. .:. H~th6ngdangshutdown. Vi~cbuyffiQtagentla mQtquitrlnhg6mhaibuoc: .:.Chuilnhi chovifChuy:agentduQcthongbaavaduQCphepke'tthuc cactrt;lngthaihi~nhanhcuanoWoc khibihuy. .:.Binh chithihanh:moitru'angdinhchivi~cthihanhcuaagent. 27 2.S'idichuy~ncua mobileagent Quatrlnhdi chuy~nco th~du'Qcyeticftubdi chinhagenthaybdi cac agentkhactrongcungmoitru'ongthi h~mh.Saudo,moitru'ongthi hanh hi~nhanh(moitru'ongthihanhngu6n)chuaagentsegii'iagentdi toimoi tru'ongthihanhdfchdffdinhtru'oc. Moi tru'ongthihanhngu6nva moitru'ongthihanhdfchseqwln11tie'n trlnhgii'iagent.Khi moitru'ongthihanhngu6nlienl~cdu'Qcvoimoitru'ong tillhanhdfch,moitru'ongihihanhdfchcoth~ho~cdaplingho~ckhongdap lingyeticftudi chuy~n.Trongtru'onghQpkhongdaplingdu'Qc,moitru'ong thihanhdfchtnl v~tinhi~u16ichomoitru'ongthihanhngu6n.Ne'umoi tru'ongthihanhngu6nkhongth~lienl~cdu'Qcvoimoitru'ongthihanhdfch, nophaitrav~tinhi~u16ichoagent. 2.1.Gui di mQtagent KhimQtmobileagentchu§nbidi chuy~n,nophaicokhanangxacdinh dfchd6ncuano.Ne'umoitru'ongthihanhdfchkhongdu'Qcxacdinh,agent sethihanhtrongmoitru'ongthihanhm~cdinhcuah~th6ngagentdfch. MQtkhivi trfcuadfchdu'Qcxacminh,mobileagentbaachoh~th6ngagent chlianor~ngno mu6ndi chuy~nWi h~agentdfch.Thongdi~pnaydu'Qc chuy€ntie'pquamQtgiaodi~nnQibQgiuaagentvah~agent(vi dl;!goO). KhimQth~agentnh~nyeticftudichuy~ncuaagent,noselamnhu'sau: .:.Dungagent:agentdu'Qcanhbaav~vi~cdi chuy~ns~pxayra va du'QCphephoanthanhlac vl;!hi~nhanhcuano,Khi di~unaythl!c hi~nxong,sl!thihanhcualu6ngcuanobi treo. 28 .:.fJanh dilu trg,ngthaiagent:tr~ngthaiva caclop dO'itttQngagent duQcdanhda'ubdidQngcd.Bay la tieDtrinht~oramQth~hi~nnha't qUailcuadO'ituQngagentd~co th~duQcmangdi trenm~ng. .:.Mil hoaagent:dQngcdmahoaagentdaduQcdanhda'uvoi giaothuc di chuy~nduQcchQn. .:.Di chuyln agent:dQngcd thietl~pket n6i voi dkh va chuy~nagent daduQcmahoadi. 2.2.Nhqnvi mQtagent Truockhid9ngcdnh~nv~mQtagent,nophclixacdinhno coth~cha'p nh~nagenttrmaygll'idi haykhong.Chi saukhinguoigll'iduQcxacnh~n thanhcongt~idQngcdnh~n,vi~cchuy~ndii'li~umoitht!cst!xclyra : .:. Nhqn vi agent:khi dQngcd dkh d6ngychuy~n,agentduQcmahoa seduQcnh~nv~. .:. Gilli mil agent:d9ngcdgiclimadongdii'li~ude'n. .:. Khoi phy,cagent:th~hi~nnha'tqUailcuaagentsaukhi danhda'use duQckhoiph~cl~i.Cac lOpd6i tuQngagentduQchi~ntht!c,tr~ngthai cuaagentduQckhoiph~c. .:.Tai thi hanhagent:agenthongbaovi~cde'ncuanot~imoitruong thihanhdkh. BaygiOnocoth~chuftnbi d~tie'pWcl~ist!thihanh cuanova duQCca'pmQtlu6ngthihanhmoi. 2.3.Di chuyln lfJpdOltti(Jngagent Agentkhongth~tiept~cl~ivi~cthihanht~idQngcddkh makhongco caclOpcuano.Co mQtsO'phudngand~lamcholOpnayco sanchodQng cddich,tily thuQCvaovi tri cualOp: 29 .:.liJp Ill-idick:ne"umQtlopdffco sant<;lidkh,ho~ctrongvimgd~m lopcuadQngcdho~ctrongh~th6ngt~ptinC1;lCbQ,thlkhongcftndi chuy€nlOp.Cac agentduQcchuy€nchicftnchuathongtin doi hoi xacdinhcaclOpnhulatendftyducualopvabQphangiai.No cling coth€ chuathemthongtinmotavi tricuadinhnghlalOp. .:.LfJpIll-ingu6n:ne"ulOpduQcd~tt<;lingu6n,dayla tru'onghQpthuong g~p,noco th€ d~dangduQcchuy€n voi tr<;lngthaicuaagenttoi dQng cddkh. Tuy nhienfa co nh~nxet r~ng:caclOptrongluQcd6 nayco th€ d~dangdi chuy€n toi dQng.cddkh nhi€u hdnmQtIftn,co th€ lam tangtai m<;lngva tangphiduongtruy€n cuam<;lng. .:.Mil lap lily vi khi can: trongtru'onghQpnay,lOpco sant<;limQt serverva dQngcddkh co th€ Iffy lOpt<;limQtdQngcdnaGdo tren m~ng.Chli Y r~ngdQngcd dkh trongtru'onghQpnayphai th1!chi<%n themmQtke"tn6i m<;lngd€ Iffy lOp. Ngltoigw Ngltoinh{ln I' It I Mc;mgmay tfnh Hinh2.4- Sl)di chuy4n clIa agent 30 Sailkhi agentdu'qckhdit';10,no thu'ongt';10ra cacd6i tu'qngkhac.R5 rang,caclapcuacacd6itu'qngnaycftnchovi~ckhdit';10vathihanhtie'p. Neuba'tklldp naotrongsO'naykhongco sant';1idQngcddich,no phai du'Qcchuy€nho~ctirngu6nho~ctu ngu'oigii'iagent.(j daytaco slfchQn llfacacphu'dnganchovi~cchuy€ncaclapphl,l:agentco th€ quye'tdinh ho~cmanghe'tcaclapcftnthie'trongmoitru'ongthihanhbandftuhaycac lopphl,lcoth€ du'qcmangtheotliyyellcftu. May phl,!cvI,! Dich (Classcode) (c) Nguon /~~ '.... t Agent \/' ~ ClassCode (b) (a) Hinh2.5- OJehuyencae lopagent III. TRAO DC)},LIEN L~C GIUA CAC MOBILE AGENT Cacagentcoth€ lienl';1cvdicacagentkhactrongclingmQtmoitru'ong thihanhhayvdi cacagentd trongcacmoi tru'ongthi hanhhanhkhac (nhu'ngclingco th€ n~mtrongclingmQtdQngcd).MQtagentco th€ yell cftumQtphu'dngthl1cuamQtagentkhachaygii'ichono mQtthongdi~p 31 n€u nodu'Qctiy quy~nchophepd€ lam vi~cnay.Thongthu'ong,vi~ctrao d6ithongdi~pgiua cac agentco th€ la m9t- m9thaym9t- nhi~u.Ki€u truy€nthongdi~pm9t- nhi~uchophepm9tagentgli'im9tthongdi~pWi ffiQtnhomcac agentdangki va la m9t cd che'huu hi~utrongh~th6ng nhi€uagent. NgVoiQui NgVoinhQn NgVoi Qui NgVoi nhQn NgVoi Qui NgVoi nhQn ThOngdi~pgliingay ThOngdi~pgltisau ThOngdi~pglii mQtchh3U Hlnh2.6- Caeki4utruyenthongdi$p Vi~ctraod6i,lien l~cgiuacacagentco th€ di~nra rheabaki€u sail : ? , .:.ThongdifjJgmngay(Now-typemessaging):dayJa kiclJ tIlJyenthong di~pdu'Qcdungthongdl;lngnha't.M9tthongdi~pgli'ingayla d6ngb9 va lamcantrdslf thihanhchotdi khi ngu'oinh~nthongdi~phoan thanhvi~cxli'11thongdi~pvah6iaml~ichono. .:.ThongdifPginsau(Future-typemessaging):m9tthongdi~pgli'isail la khongd6ngb9vakhongcantrdvi~cthihanhhi~nhanh.Ngu'oi gU:igill mQt"the bai" co th€ duqc duI\~d€ n.h~n.k€t ,\ua..Do n.~uoi gli'ikhongphaichochoWi khi ngu'oinh~nh6i dapva gli'ih6i am, 32 ki~utruy€nthongdi~pnaylinhdQngvala d~cbi~thUlllchkhinhi€u agentlienlc;tcvoinhau. .:.ThongdifPgia ml)tchilu (One-way-typemessaging):mQthongdi~p gii'imQtchi€u la khongd6ngbQva khonglamcantrd sl! thihanh hi~nhanh.Nguoigii'isekhonggifi'lc;ti"thebai"d~xii'11thongdi~p nay,vanguoinh~nsekhongc~nphaih6iamlc;ti.Ki~utruy€nthong di~pnaythu~nti~nkhihaiagentduqctie'nhanhcuQctraod6ibang ke'tn6i khongduqcduytrllien tl;lc.Luc nayagentgii'ithongdi~p khongc~nba'tkl h6iamnaotli'agentnh~nthongdi~p. IV.JAVA vA CAC Ht MOBILE AGENT 1.Cae di~mthuQnlc;1icua Java khixcy dtjngmobileagent Javala mQtngonngfi'l~ptrlnhhuangd6ituqngvathanthuQcvoi mc;tng. C6th~noiJavala mQtphudngti~nhoanhaochomobileagent.Saudayla mQtsO'd~ctinhcuaJava minhhQachonh~ndinhnay: 1.1.Dl)clijpviiihf nln Javaduqcthie'tke'd~thihanhtrongcacmoitru'ongkhongd6ngnha't. E>~IDQtlingdl;lngJavaco th~thihanhba'tcli datitrongmc;tng,trlnhbien dichphatsinhkie'ntructrungl~pbytecoded6il~pvoimangu6nkhongth~ mangchuy~n.D~manaycoth~thihanhtrenmQtmaynaodo,h~th6ng tillhanhJavaphait6ntc;ti.Javala ngonngfi'dQcl~pvdicacd~ctinhcuah~ n~n.Cacki~udfi'li~unguyenthuyduqcdinhnghlamQtcachch~tcheva khongphl;lthuQcvao bQxii'11hayh~di€u hanhbell duoi.Ngay ca cacthu vi~ncling la cac ph~ndQcl~pvoi h~di€u hanh.Vi dl;l,thu vi~ncii'as6 33 cungca'pmQtgiaoti€p donghincuagiaodi~nd6hQadQcl~pvoih~dieu h~mhbell duoi.No chophepchungtat~ocacmobileagentma khongcfin bie'tloc:LimayHnhmanosethihanhtrendo. 1.2.Thi hanh an toan JavadU<;1cdungchoInternetva cacintranet,dodo yell cfiuve Hnhan loandaanhhuangd€n thi€t ke'theonhieucachoVi dl;l,Java co mQtmo hinhcontro bQnho giup.loc:Litru cac kha Dangxamphc:LmbQnho va lam hOngdii'li~u.Java khongchophepvi~cchuy€n ki€u ba'th<;1pl~hayba'tki phepto£lnsf)hQcnaotrencontro.Cac chuangtrinhkhongth€ gia mc:Lotroy c~ptdidii'li~uriengtrongcacdoi tu<;1ngmachungkhongco co quyentruy c~p,dieunaygiupnganch~nnguycdvirus.Th~mchine'uco nguoixam phc;tmvoibytecode,h~thongthihanhcuaJavav~nch~cdingmanayse khongcokhaDangxamphc:Lmcacngii'nghlacuaJava. Javaclingco mQttrlnhquail11sl/ anloan d€ kiSmtra loan bQcacthao tackh6nganloan tiemfin,vi dl;lnhutroyc~pt~ptin hayke'tnf)imc:Lng,dS xacdinh chuangtrlnhdo dU<;1cphepthi hanhcacthaolac nay haykhong. N6ichung,kie'ntrucanloancuaJava lam chono du anloan d€ ki€m soat caeagentkhongtinc~y,bai vi nokhongth€ canthi~pvaocacmayphl;lC Vl;!haytroyc~pcacthongtindaubrieng. 1.3.Tai [updQng Cdch€ tai lOpdQngchophepmayaon~pvadinhnghlacaclop trong .>' hIethih~lllh.No clingca'pmQtkhonggiantendU<;1cbaav~chom6i agent, 14 dodochophepcacagenthihanhanloanvadQCl~pvoinhungagentkhac. Cdche'tiii lOpmdrQngdll<;1cchophepcaclopdl1<;1ctiii quam~ng. 1.4.L4P trinh daluiJng Cacagentla tlftri:nghIala agentcoth€ thihanhdQcl~pvoi cacagent khacclingt6nt~itrongm6itrttongthihanh.Chophepm6iagenthihanh tronglu6ngcuanola mQtcachchophepcacagentcokhiinangtlflingxU'. 1.5.Danh diiu dol tlit/ng MQttinhchfttquailtrQngcuamobileagentdo la chungco th€ dl1<;1cdanh da'utr~ngthaihi~nhanhva kh6iphl;lCl~itr~ngthaidadanhdftu.Java cling ca'pmQtcd che'danhda'ura'tthu~nti~ndl1<;1cxay dlfngsand€ co th€ bi€u di~ntr~ngthaicuamQtd6i tl1<;1ngdl1oid~ngtu§ntlf hoadu chi tie'tsaocho doitu'<;1ngco th€ tai kie'ntrucl~isaunay.D~ngtu§ntlf hoacua d6i tl1<;1ng phaicokhanangxacdinhcaclOpJavamatudocactr~ngthaicuad6i tu'qngdl1<;1cIttul~iva khii nangphl;lCh6i tr~ngthaitrongmQtth€ hi~nmoi. Cacd6i tl1<;1ngthl1ongthallichie'ude'ncac d6i tl1<;1ngkhac.D€ duytrl cftu trucd6i tl1<;1ng,hungd6i tl1<;1ngkhacnayphiii dl1<;1clttutm va kh6i phl;lC clingmQtluc. Khi mQtd6i tl1<;1ngdl1<;1clttutrU,tfttcii cacd6i tll<;1ngtrongd6 thico th€ troy c~pdl1<;1ctu d6i tl1<;1ngdo cling dl1<;1clttutill. 2.MQtsohQnchecua Java M~cdli ng6nnguJavarfttthichh<;1pchovi~ct~ocacmobileagent,tuy nhiennovftncomQtso'nhl1<;1cdi€m danglttuy.MQts6trongchungcoth€ du'<;1ckh~cphl;lC;nhungcaikhacquailtrQnghonva co lienquailde'nthie't ke'quailni~mvaphattri€n t6ngth€ cuacach~mobileagentdlfatrenJava. 35 2.1.Thituhgtr(1kiim soulngudntainguyen NgonnguJavakhongclingca'pcacphu'dngti~nchochungtaki~msoat cactainguyendu'cJcdungbdimQtd6itu'cJngJava.VI dl;l,mQtagentcoth~ chi€mbQxli'11,va chie'mtainguyenbQnhob~ngcachkhongtlf giai phong. HaiVI dl;lnay lien quailde'nmQtd(;lngCl;lth~cuata'ncongslf anloan du'cJC gQila phahongdichVl;ln~n.MQttrongnhunglo(;lita'ncongdangscJnha'ttu mobileagentdo la: cac agentdi chuy~nthanhdan vao mQtmay tinh va chi€mta'tca cactai nguyencuano, lamchongu'oidi~uhanhkhongth~ ki~msoatdu'cJcmaytinh.Javakhongclingca'pcachnaochomaytinhd~ gioih(;lntai nguyenCPU va bQnhodu'cJc a'pphatchomQtd6i tu'cJnghay lu6ng. MQtva'nd~khaclien quailthlfCslfVu'cJtquat~mJava la khanangagent ca"phattai nguyen ngoai chu'dngtrinh,VI dl;lnhu'mdcac t~ptin, cac socket vat(;lOcaccli'as6.Vi~cca'pphatcuaagentrencactainguyennaycoth~ dU<;1cki~msoat,nhu'ngmQtkhiagentbi buyhaydu'cJchuy~ntoimQtmay , khacnhungtainguyennayphaidu'cJcgiaiphong.Tuynhien,th~tkhoma lamdi~unaybdivi Javakhongh6trcJchovi~cke'thcJpcactainguyennhu' v~ychomQtd6i tu'cJngCl;lth~nao.Do do chungtaco th~tha'ymQtmobile agentquellgiaodi<%nd6hQacuanovabo l(;limQtcli'as6dangmdtrenman hinhcuachungtakhinodoiWimQtmaykhac. 2.2.Vi~cthamchitu khongdzt(Jcbaov~ Cacphu'dngthuccongkhaicuacacd6i tu'cJngJava la dungdu'cJchoba't ki d6i tu'cJngnao khac co thamchie'uWi no. Bdi vi khongco khai ni<%m 36 thamchienduQcbaav~,mQts6d6i tu'QngduQcpheptroyc~ptoi t~pIon hdncacphuongthuccongkhai tronglop giaotiep cua d6i tuQngJava hon caed6ituQngkhac.Ki€u troyc~pnayla quailtrQngchoagent.Khongco eachnaod€ agentcoth€ trv'ctiepgiamsatvaki€m soatnhii'ngagentkhac dangtroyc~p toi cacphuongthuccuano. MQtgiaiphapt6tchovffnd€ naydola duavaod6ituQngd~idi~ngiii'a nguoigQi(nguoiyellc~u)va nguoiduQcgQid€ ki€m soatvi~ctruyc~p. Cachtiepc~nnaykhongchiclingcffpvi~cbaav~cacmaconduaramQt giaiphapchobai loand€ c~ptieptheovaclingcffps11trongsu6tv€ vi tri n6ichung. 2.3.Khong co thamchie'usdhuudol tzt(lng Khongai sdhii'ucacthamchie'utoimQtd6ituQngtrongJava.Voi mQt agent,di€u ngayc6nghlala,nguaitacoth€ Iffynhanhthihanhrakhoino, nhungkhongth€ lo~ibochinhagenthayd6ituQng.Dayla mQtlacvl;lcho bQdQnrac.Hi~nnay,bQdQnracsekhongphl;lCh6ibfftkl d6i tuQngnao chotoikhitfftcacacthamchie'uWid6ituQngnaydaduQclo~ibooDo do ne'umQts6agentnaodocothamchienWiagentcuachungta,nosekhong tranhduQcvi~ct~okehdchoagentdo d€ giii'choagent6nt~itraivoiy mu6ncuachungta.Tfftcanhii'ngl chungtacoth€ lamla l~pl~ilai canh caod€ khoi demchocacthamchientrtfctieptoi cacagenttrongJava. 2.4.Khong hg tr(lchovi?cduytri vabiltdilu [(litr(lngthai thi hanh Hi~nthai Java khongth€ khoi phl;lCloanbQtr~ngthai thi hanhcuamQt d6ituQng.Cac thongtinnhula tr~ngthaicuacontro chuangtrlnhva ngan 37 xe'pluaula vimgbi ca"md6icacch11'dngtrlnhJava.Do do,d€ mQtmobile agentba:tdffuvi~cthihaOOtiOOloanmQtcachchiOOxactrenmQtmayd xa,nophaid1!atrencacgia tri thuQctiOOnQiva cacbi€n co'bell ngoaiWi notI1!cti€p. MQt s1!t1!dQnghoad11'Qcnhungvaoco th6gifi'v€t cualQtrlnh cuaagentva cha:ccha:nding vi~ctiOOtmlnla d11'Qcngitngva ti€n hanhl~i dung. V. AGLET: MO HINH MOBILE AGENT DVA TREN JAVA Agletla cacd6i t11'Qngd11'Qcxftyd1!ngbAngJavaco th6di chuy6ntit maynaysangmaykhactrenInternet.Nghlala, mQtagletdangthihanh trenmaynayco th6dQtngQtngitngthihaOO,t1!gli'imlnhtdi mQtmaykhac (j trenm~ng,va thi hanhti€p d do. Khi agletdi chuy6n,no mangrheama chl1dngtrlnhclingnh11'dli li~ucuano. Agletla mQtJavamobileagenth6trQcackhaini~mthihanht1!triva dinhtuy€ndQngtrenlQtrlOOcuano.Coth6xemaglet0011'Ia mQtkhaiquat hoavamdrQngcuaJavaappletvaservlet.Agletd11'Qcdi€u khi6nbdimQt Agletserverrheacacht11'dngtv nh11'cacappletd11'Qcdi€u khi6nbdi trlnh duy~tweb.Agletserverclingca"pmQtmaitru'ongchocacagletthihanhva mayao Javava trlOOqUailIi an loanagletdambaoanloand€ OO~nva ki~msoarcacaglet.Agletla titghepgiliaagentvaapplet. 1.Aglet API AgletAPI la mQtbQcongC1;}phattri€n agent- noi cachkhac,la mQtt~p caelOpvagiaodi~nJava chophept~ocacmobileagent.AgletAPI du'Qc caenhanghienCUllcuaIBM t~iNh~tBanphattri6n. 38 Di~mdQcdaocuaAgletAPI dola mdrQngkhaDangn6itie'ngcuacac chu'dngtrinhJavadola : "vie'tmQtlan,thihanhbfftClld dati",d~apd\lng chocacmobileagent.Kha Dangnaydu'QCdi&nd~tthanh"vie'tmQtlan,hill h~lllhbfftClldati".NghlaJa, mQtkhi agletdu'QCt~ofa, no sech~ytrenmQi mayco h6 trQAglet API. Chungtakhongcanquailtamde'nh<%di€u hanh va phanclingbell du'oihay ngu6ng6c cua cai d~tC\l th~cua Aglet API trenmaymaagletdangch~y. AgletAPI phananhmohinhappletcuaJava.M\lc dfchla demd~ctinh didQngvaoapplet.Mo hinhnaydu'Qcthie'tke'd~t~nd\lngcacIQithe'tu cacd~cdi~magentcuaJava d6ngthai vu'Qtquanhungthie'usot trongh<% ngonngunay.Trongmohinhd6i tu'Qngaglet,mQtmobileagentla mQtd6i tu'Qngdi dQngco lu6ngki~msoatrieng cuano, lam vi<%ctheosl! ki<%n,va lienl~cbiingcachtruy€n thongdi<%p. 2.Cae thanhphoncd ban Bay giOchungtasexemxetkI hdnmohinhcdbancuaAgletAPI. Mo hinhnaydu'aramQts6khaini<%mtrliutu'Qngbaag6m:aglet,d6itu'Qngd~i di<%n,ngucanhthihanhva dinhdanh: .:.Aglet:la mQtd6i tu'QngJavadi dQngco th~di chuy~nde'ncacmay chophepdungagentrongm~ng.No la tl!tri,bdivinothihanhtrong nhanhriengsailkhide'nmaydo,va tu'dnglac,bdivi no co th~dap trah.dcacthongdi<%pde'n. .:. f)ol t"(lngd{lidi~n:dongvai tra nhu'mQtlOpbaav<%agletkhoi cac truyc~ptnfctie'ptoi cacphu'dngthllCcongkhaicuano.D6i tu'Qngd~i 39 di~nclingcungca'pslftrongsu6t~~vi tr!choaglet,nghlala, no co th~da'uvi tri thlfccuaaglet.E>i~unayconghlala mQtagletva cac d6itu'<;1ngd~idi~ncuanocoth~duQctachriengrad~d6ituQngd~i di~nClJCbQcheda'uslfcachbi~tcuaaglet. ."""-'--'-""-'--"""'--""""". Clients <Tlldng tac ~ I ' Hlnh2.7- M6iquan h$ giGaAgletva d6itvqngdQidi$n .:.Ngil canhthihanh:la mQtmoitr1.tanglamvi~ccuaaglet.Gffntu'dng tlfvdikhaini~mmoitru'angthihanhdu'<;1cgidithi~udphffntru'dc.No la mQtd6i tu'<;1ngtInhcungca'pphu'ongti~nd~duytrl va qmln11cac agletdangthihanhtrongmQtmoi tru'anglamvi~cnha'tqUailmad do h~th6ngcacmaydu'<;1cbaav~anloantranhcacagletphaho~i.MQt maytrongm~ngco th~thihanhnhi~udQngcd,va m6idQngcdco th~qUail11nhi~ungfi'canhthihanh.Cac ngfi'canhthi hanhdu'<;1cd~t tenva dodo co th~du'<;1cdinhvi biingcachke'th<;1pdiachi moi tru'ang thihanhvatencuachung. .:.Binh danh:du'inhdanhnayla duynha'tloan clJcvakhongthayd6itrongthaigians6ngcuaaglet. V€ cdbanchi co haicacht~oraslf s6ngchomQtaglet:ho~cla du'<;1ct~o ho~cla du'~ki~mgOatso'1u'<;1ngcac aglet,chungtacoth~huychung. 40 May tinh NgCtcanh thi hanh NgCtcanh thi hanh NgCtcanh thi hanh E>Qngcd MQng Hlnh2.8 - M6iquanh$ giQamay tfnh,dQngCdva ngQcanh thihanh Cacagletdi dQngtheohaicachkhacnhau:chudQngvabi dQng.Cach tie'pc~nchudQngdu'Qcmota bdimQtaglett1;1'no dffytirmayhi~nhanh chuano tdi mQtmayd xa.MQtmaykeomQtagletrakhoimaychuhi~n hanhmota d~ngbi dQngcuas1;1'di dQngcuaaglet.Khi cacagletdangthi hanh,chungchie'mcactainguyen.D~h~nche's1;1'lieu tontainguyencua , chung,cacagletcoth~t~mthoikhongho~tdQng,tral~icactainguyen,va saildoco th~du'Qcdu'atrdl~iche'dQthihanh.Cuoicling,nhi~uagletco th~traod6ithongtind~hoanthanhmQtlacvl;!naodo. Dayla t~ptoithi~ucacthaolacdoihoichovi~ct~ovaqUail11mQtmoi tHrongmobileagentphantan. Nhu'v~y,cacthaolaccdsdcuamQtagletbaag6m:t~o,nhanban,gti'i di,keol~i,ngu'ngho~tdQng,ho~tdQngl~i,vahuyboo 41 .:.Tlf,o:vi~ct~omQtagletxayra trongmQtngii'canhthihanh.Aglet. moisedu<;JcgallmQtdinhdanh,chenVaGngii'canhthih~lllh,vadu<;Jc khdit~o.Agletb~tdffuthvchi~nngaykhino du<;Jckhdit~othanh congo .:. Nhiin ban: nhanban agletse t~ora ffiQtbansaGra'tgi6ngvoi aglet Dand~\l\Iongcungng\!dum\ninann.S\fKhacnnauuu-yI\n~t\1\a\1ill. danhdu<;Jcgallva vi~chanhthihanhb~tdfful~itrongagletmojoChu ydingcaclu6ngthi.h~lllhkhongdu<;Jcnhanban. .:.aili di: gll'imQtaglettumQtngii'canhthih~lllhtoimQtngucanhthi hanhkhacsedemnotungucanhthihanhhi~nhanhvachennoVaG ngucanhthihanhdfch,ndino seb~tdfful~isvthihanht~ido (cac lu6ngthihanhkhongdu<;Jcdaidi).Chungtanoidingag1etdu<;Jcdffy Wingucanhthihanhmoicuano. .:.KeoIlf,i:vi~ckeGag1etl~iseloi nokhoingucanhthihanhhi~nh~lllh va chenno VaGngucanhthihanhmatu do vi~ckeGl~idu<;Jcyell c~u. .:. Kich hOlf,tva tlf,mngltng:t~mngungmQtaglet1akha nangtC;lmthai dungsvthihanhcuanova-100tm trC;lngthaicuano va thie'tbi hill trU ph\!nhuiliacling.KichhoC;ltcuamQtagletsekhoiph\!cnotfongcling ngucanhthihanh. .:.Buy hi}:vi~cbuymQtagletsedlnhchisvthihanhcuanova10C;libo nofakhoingucanhthihanhhi~nhanhcuano. 42 -... Ngl1canh thlhanhA Ngl1canh thlhanhB Nhan ban Guidi KeolQi TQo TQmngLlng Kh6i phl,Jc IQi Lop Dia cang Hinh2.9 - Chu kl song CLIOAglet 3. Mo hinh bienco Mo hinhl~p trlnhalgerla d1;1'atrenbie'nc6.Mo hinhnay chophepngu'oi l~ptrlnhthemvao cac listenersdu'Qctuy bie'nvao aglet.Cac listenerbat eaebie'nc6d~cbi~ttrangchuki s6ngcuamQtagletvachophepngu'oil~p trlnhxli'11,vid\lnhu',khiagletdangdu'Qchuy~ndi. C6balo~ilistener: .:. Clone listener:dungchocacbie'nc6nhanban.Chungtaco th~tuy bie'nlistenernay d~co mQthanhdQngC\lth~nao do khi mQtaglet sapdu'QCnhanban,khi vi~cnhanbandu'Qcth1;1'cs1;1't~ora,va sailkhi vi~c nhanbanxayra. .:.Mobilitylistener:dungcacbie'nc6didQng.Chungtacoth~sli'd\lng listenernayd~xli'11khimQtagletsapdu'QCgli'itaimQtngil'canhthi hanhkhac,khisapdu'QCrutl~itu mQtngil'canhthihanh,va khino thl!csl!de'nmQtngil'canhthihanhmaio 43 .:.Persistencelistener: Dungchocacbie'nceSkfchho~thay t~mngu'ng. Listenernay chophepl~ptriOOvien xii'11khi mQtagletsapbi t~m ngu'ngva sailkhi nodu'<;1ckf hho~tl~i. 4.Me)hinhtreed6i, lien IQc Cacagletlienl~c,traod6ib~ngcachtruy€nthongdi~p.Ti~nfchtruy~n thongdi~pchophepcacaglett~ova traod6i cacthongdi~ptheoOOi~u eachlinhho~t.M~cdinh,vi~ctruy~nthonggiii'acacagletkhongthuanh~n vi~cxii'11thongdi~pcungmQthic.Di~unayconghlala tfftca cacthong di~pphai du'<;1cxii'11tu~nW'. Ngoaiagletva deSitu'<;1ngd£;lidi~n,cacthanhph~nsailla cacthanhph~n quantn;mgcuamohlnhlien I£;lCgiii'acacaglet .:. Thong di~p:la mQtd6i tu'<;1ngdu'<;1ctraod6i giii'acac aglet.No cho phepvi~ctruy~nthongdi~pd6ngbQclingOOu'khongd6ngbQgiii'a cac aglet.Cd che'truy~nthongdi~pco th~du'<;1cdungbdi cac aglet d~cQnglac va traod6i thongtin trongd£;lngke'tneSikhongdu'<;1cduy trllien t\Ic. .:. Thong di~ph6i am sau:du'<;1cdungtrongvi~cgii'ithongdi~pkhong d6ngbQ OOu'lamQt"thebai"chophepngu'oigii'ithongdi~pnh~n mQth6iammQtcachkhongd6ngbQ. .:.Tljpcacthongdi~ph6iamsau:coth~chuanhi~uthongdi~ph6iam sailvadu'<;1cdungd~Iffyke'tquakhinaono co.Vdi deSitu'<;1ngnay, ngu'oigii'iclingcoth~chQnIffyke'tquad~utienvaboquacacke't quake'tie-p. 44 Agenf/(fngdl,lng :"'.'~'UI"~~~'~.>~:S"" <H61d6P I v Hinh2.10- Traod6i thongdi$p giQaAglet- Aglet VI. KET LU~N MQth<%th6ngmobileagentbaag6mhaithanhphftnchinhdo la mobile agentvamoitntangthihanhmobileagent("h<%di~uhanh"mobileagent). Mobileagentla cacthlfcth~dichuy~nkhapnditrenm~ngsailkhiduQct~o fa.Khi d6nm6imaytrenm~ng,nophaithongquamoitntangthihanhd~ coth~th1!Chi<%ncac lac v\l cuamlnhclingnhu'sii'd\lngcactai nguyencua h<%th6ng. MQtmobileagentla mQtth1!Cth~co namthuQctinh,do la: tr~ngthai, macaid?t,giaodi<%n,dinhdanhvathanchu.CacthuQctinhtr~ngthai,ma caid?tdungd~mobileagentcoth~thihanhl~isailkhid6nmQtmaymoi. ThuQctinhgiaodi<%nva dinhdanhgiupchomobileagentco th~lien l~c , duQcvoi caeagentkhacclingnhu'giupchomoitntangthi hanhquail11 chung.ThuQctinhthanchudu'Qcdungchocacvffnd~anloan.f)~dambaa .anloanclingnhu'tinhtrongsu6tv~vi trI,cacmobileagentdu'araphftntii' d~idi<%nd~giao ti6pvoi cacthlfCth~bell ngoai(vI d\l nhu'moi tntangthi hanh,cacagentkhac,...). Trongsu6tthaigiant6nt~icuamInh,mobileagentcobathaolaccdban nhfftdo la t~o,buyva di chuy~n.Cac thaolac nayd~udu'Qcthlfchi<%ntrong moitntangthi hanh.Nhi<%mV\lchinhcuamoi tntangthihanhla qUail11va botIP cac mobileagenttbjbanbcungnhu's11d¥ngcaetalnsuyencuah~ 45 th6ng.Moi tntangthih~lllhphaichophepnhi€u agentcungt5rit'}.ivaho'}.t dQngd5ngthai,riengbi~tnhau;clingnhuh6tn;1vi~ctraod6i,thuangluQng giii'acacagent.Ngoairamoitrltangthihanhconphaidambaaantoancho caeagentruocs1;1'phaho'}.icuacacagentkhac,clingnhubaav~h~th6ng tn1ocs1;1'phaho'}.icuacacagentghede-no Do cac ltu di~mn6i b~tcua mlnhvoi vai tro la ngonngii'l~ptrlnht6t nha'ttrenm'}.nghi~nnay,JavathuangduQcdungd~caid~tcach~th6ng mobileagent.Chuangnayclingda:gioi thi~umQth~th6ngmobileagent dl/atrenJavaduQcclingca'pbdicacnhanghienCUllIBM, Nh~tBand6la Aglet.Dayla moitruangmalu~nvansad\lngd~xayd1;1'ngcacungd\lng minhhQa. cg 8D f,G)(\:Q 46