Antonius Rachmat C, S.Kom, M.Cs

  Arsitektur Aplikasi p Perangkat Enterprise #10 g p s # 0

  Ant onius Rachm at C, S.Kom , M.Cs A t i R h t C S K M C WWW “ Today, t he principal use of t he World Wide Web is for int eract ive access t o docum ent s and applicat ions.

  I n alm ost all cases, such access is by hum an users,

t ypically w orking t hrough Web brow sers, audio players, or

ot her int eract ive front end syst em s. ot her int eract ive front - end syst em s The Web can grow significant ly in pow er and scope if it is

ext ended t o support com m unicat ion bet w een applicat ions, ext ended t o support com m unicat ion bet w een applicat ions

from one program t o anot her.”

  From t he W3C XML Prot ocol Working Group Chart er From t he W3C XML Prot ocol Working Group Chart er

  World Wide Web ld d b t he Web i t he o ld’ l ge t lient / e e

  ‡ t he Web is t he w orld’s largest client / server syst em com m unicat ion occurs via m essage passing com m unicat ion occurs via m essage passing

  ‡ w it hin brow ser, select URL of desired page

  ‡ brow ser request s page from server

  ‡ server responds w it h m essage cont aining

  ‡ server responds w it h m essage cont aining

  ƒ type of page (HTML, gif, pdf, zip, …)

  ƒ page contents ‡ brow ser uses t ype info t o correct ly display page

  ‡

if page cont ains ot her it em s ( im ages, applet s, …) ,

browser must request each separately

  Yesterday… d

  Now, Web Service… b S

  ‡

W e b Se r vice s ca n con ve r t you r a pplica t ion s

in t o W e b- a pplica t ion s.

W b S i t li t i

  „ By using Web services, your applicat ion can publish it s „ By using Web services, your applicat ion can publish it s funct ion or m essage t o t he rest of t he world.

  ‡

W e b Se r vice s ca n be u se d by ot h e r a pplica t ion s a pplica t ion s

  „

  Ex: wit h Web services your account ing depart m ent 's Win 2k servers can connect wit h your I T supplier's UNI X server.

  „

  Can be used as API

  ‡

  ‡ Th e ba sic W e b Se r vice s pla t for m is X M L + H TTP.

Th e ba sic W e b Se r vice s pla t for m is X M L +

  Pengertian-pengertian ‡ ‡ Ge n e r ic: Any applicat ion accessible t o ot her applicat ions Ge n e r ic: Any applicat ion accessible t o ot her applicat ions

  over t he Web

  „ Very open definit ion, alm ost any URL becom es a “ Web service” under t his definit ion under t his definit ion

  ‡ UD D I con sor t iu m : Web services are self- cont ained,

  m odular business applicat ions t hat have open, I nt ernet - orient ed, st andards- based int erfaces

  „ Bet t er, but st ill not specific enough ‡ W 3 C: A Web service is a soft ware applicat ion ident ified by

  a URI , whose int erfaces and bindings are capable of being defined, described, and discovered as XML. A Web service d fi d d ib d d di d

  XML A W b i support s direct int eract ions wit h ot her soft ware agent s using XML- based m essages exchanged via I nt ernet - based prot ocols prot ocols

  „ Slight ly bet t er Pengertian-pengertian ‡

W ik ipe dia : According t o t he W3C, a Web service

  is a soft w are syst em designed t o support int eroperable m achine- t o- m achine int eract ion int eroperable m achine- t o- m achine int eract ion over a net w ork. I t has an int erface t hat is described in a m achine- processable form at such p as WSDL. Soft w are applicat ions w rit t en in various

program m ing languages and running on various plat form s can use web services t o exchange dat a l f b i h d over com put er net w orks like t he I nt ernet in a

m anner sim ilar t o int er- process com m unicat ion m anner sim ilar t o int er- process com m unicat ion on a single com put er. WS Example S l ‡ ht t p: / / www.google.com / apis/

  ‡ ht t p: / / t erraserver.m icrosoft .net / TerraServ p ice.asm x

  ‡ ‡ ht t p: / / www.xm et hods.net ht t p: / / www.xm et hods.net

  ‡ ht t p: / / soap.am azon.com / schem as2/ Am az onWebServices.wsdl onWebServices wsdl

  ‡ ht t p: / / api.google.com / GoogleSearch.wsdl

  Example: A Google Client E l A G l Cli ‡

  Creat e a local proxy class, inst ant iat e, and invoke ‡

  The proxy class generat ed from a WSDL file, an XML- MyService encoded service descript ion encoded service descript ion

  Dim MyLicenseKey As St ring ' Variable t o St ore t he License Key ' Declare variable for t he Google search service Di Dim MyService As com .google.api.GoogleSearchService = New _ M S i A l i G l S hS i N com .google.api.GoogleSearchService ' Declare variable for t he Google Search Result Dim MyResult As com .google.api.GoogleSearchResult y esu t s co goog e ap Goog eSea c esu t ' Please Type your license key here MyLicenseKey = " t GCTJkYos3YI t LYzI 9Hg5quBRY8bGqiM" ' Execut e Google search on t he t ext ent er and license key M R MyResult = MyService.doGoogleSearch( MyLicenseKey, _ lt M S i d G l S h( M Li K

  Text Box1.Text , 0, 1, False, " " , False, " " , " " , " " ) ' out put t he t ot al Result s found Outline Architecture l A h

My Desktop The I nternet Google.com/ apis

Windows TCP/ I P / Unix/ Linux? /

  MyService s = [WebMethod] new _{com .google.api.GoogleSearchService}

  … doGoogleSearch(myKey, q) … ();

  I mplementation via I l t ti i I l t ti i I mplementation via

  Request Request proxy class and

  WebService classes HTTP transport in Web Server

  Google Contoh web service C h b

  

Application Solution Provider, Software

as a Service vs Web Service

  Web Service ‡

  Mem pert ukarkan dat a dalam form at XML. M t k k d t d l f t XML ‡

  

Tersedia dan dikom unikasikan m elalui I nt ernet

at au int ranet . at au int ranet ‡

  Bersifat operat ing syst em / program m ing language independent . p ‡ Berupa web applicat ion yang t idak m em iliki web int erface.

  ‡ Web service m em pert ukarkan dat a ant ara service request or ( aplikasi yang m enggunakan request or ( aplikasi yang m enggunakan dat a/ service) dan service provider ( server p penyedia dat a/ service) m enggunakan service y / ) gg

regist ry ( yang berisi kum pulan service- service) ,

dengan salah sat u t eknologi:

  Web Service b S ‡ ‡

  Web service berbeda dengan m odel aplikasi Web service berbeda dengan m odel aplikasi

t erdist ribusi t radisional sepert i CORBA dan RMI

dim ana m et hod yang dipanggil dieksekusi m elalui j aringan dan m enghasilkan j i d h ilk r e su lt berupa va lu e lt b l m et hod t ersebut , sedangkan web service

m enyediakan m et hod yang akan m enghasilkan

r e su lt berupa da t a XM L ( bukan dat a biner) lt b d t XM L ( b k d t bi )

  ‡

Web service dapat dipanggil/ digunakan m elalui

w eb, aplikasi deskt op, at aupun aplikasi m obile w eb, aplikasi deskt op, at aupun aplikasi m obile

  ‡ Kelebihan:

  „

  I nt eroperabilit y ( plat form dan aplikasi)

  „

  Dapat m em publikasikan service dan m et hod sehingga Dapat m em publikasikan service dan m et hod sehingga m udah digunakan

  „ Mendukung reusable- com ponent s

  Website vs Web service b b ‡

  Mem iliki w eb int erface ‡

  Dibuat unt uk berint eraksi langsung dengan user ‡

  Dibuat unt uk bekerj a pada w eb brow ser ‡

  Bersifat front - end ‡

  Bersifat hum an- cent ric: m anusia m enj adi akt or ut am a Website vs Web Service b b S ‡

  Tidak m em iliki int erface yang baik Tid k iliki i f b ik

  ‡

  Dibuat unt uk berint eraksi langsung dengan applikasi yang lain, baik berbeda OS sekalipun, bukan dengan user. a , ba be beda OS se a pu , bu a de ga use

  ‡

  Dibuat unt uk bekerj a pada sem ua t ipe client applikasi / perangkat device

  ‡

  Bersifat behind t he scene. B if t b hi d t h

  ‡ Bersifat applicat ion- cent ric: kom unikasi t erj adi ant ar

  aplikasi p TT h d HTTP Methods ‡

  GET ( ret rieve a resource) ‡

  HEAD ( ret rieve m et adat a about a ( resource) ‡

  POST ( add inform at ion t o a resource) ‡

  POST ( add inform at ion t o a resource) ‡

  PUT ( creat e a new resource / upload) ‡

  DELETE ( delet e an exist ing resource) ‡

  DELETE ( delet e an exist ing resource) WebDAV b A ‡ ‡

  W e b- ba se d D ist r ibu t e d Au t h or in g a n d V e r sion in g is a W e b- ba se d D ist r ibu t e d Au t h or in g a n d V e r sion in g is a

  set of ext ensions t o t he Hypert ext Transfer Prot ocol ( HTTP) which allows users t o collaborat ively edit and m anage files on rem ot e World Wide Web servers on rem ot e World Wide Web servers

  ‡

  The prot ocol facilit at es " I nt ercreat ivit y" , m aking t he Web a readable and writ able m edium

  ‡ ‡

  The original vision of t he Web as expounded by Tim The original vision of t he Web as expounded by Tim Berners- Lee was a bot h readable and writ able m edium .

  ‡

  I n fact Berners- Lee's first web browser, called WorldWideWeb, w as able t o bot h view and edit w eb pages; W ldWid W b bl t b t h i d dit b but , as t he Web grew, it becam e, for m ost users, a read- only m edium . Jim Whit ehead and ot her like- m inded people want ed t o fix t hat lim it at ion want ed t o fix t hat lim it at ion WebDAV b A ‡

  PROPFI ND PROPFI ND — Used t o ret rieve propert ies, st ored as XML, U d t t i t i t d

  XML from a resource. I t is also overloaded t o allow one t o ret rieve t he collect ion st ruct ure ( a.k.a. direct ory hierarchy) of a rem ot e syst em . of a rem ot e syst em

  ‡

  PROPPATCH — Used t o change and delet e m ult iple propert ies on a resource in a single at om ic act .

  ‡ MKCOL — Used t o creat e collect ions ( a.k.a. direct ory) . ‡ COPY — Used t o copy a resource from one URI t o anot her. ‡ ‡ MOVE MOVE — Used t o m ove a resource from one URI t o anot her. Used t o m ove a resource from one URI t o anot her. ‡

  LOCK — Used t o put a lock on a resource. WebDAV support s bot h shared and exclusive locks.

  ‡ ‡

  UNLOCK — To rem ove a lock from a resource. UNLOCK To rem ove a lock from a resource

  WebDAV alternatives b A l ‡

  CMS ( Cont ent Managem ent Syst em ) ‡

  FTP wit h CVS ( Cont rol Versioning Syst em ) ( g y ) / SVN ( Subversion)

  ‡ SMB Prot ocol ( Sam ba and Windows)

  ‡ SMB Prot ocol ( Sam ba and Windows)

  ‡ Wiki Syst em

  ‡ Web Service

  ‡ Web Service

  Back: Web Service properties k b S

  W b i h ” lf d ibi ” j ik kit b t

  ‡

  Web service harus ” se lf- de scr ibin g” : j ika kit a m em buat web service, kit a harus j uga m em publikasikan public int erface yang dapat dim engert i dan dipakai.

  Mi i l i h iliki h d bl „

  Minim alnya, service harus m em iliki h u m a n - r e a da ble docu m e n t a t ion sehingga developer lain dapat m engint egrasikan aplikasinya dengan w eb service yang kit a buat buat .

  „ Kit a w aj ib m em buat pu blic in t e r fa ce sehingga dapat digunakan unt uk m engident ifikasikan sem ua m et hod yang public, argum en- argum ennya dan j uga ret urn valuenya. p , g g y j g y

  ‡

  Web service harus ” discove r a ble ”: j ika kit a m em buat web service, harus ada m ekanism e sederhana agar service dan public m et hod yang kit a buat dapat dikenal dan dit em ukan p y g p oleh aplikasi lain. WS Layer WS Layer ‡

  Service t ransport S i t t „

  Bagian ini bert anggung j aw ab unt uk m e n gir im m e ssa ge ant ar aplikasi. m e n gir im m e ssa ge ant ar aplikasi

  „ I nt ernet Prot okol yang ada di bagian ini: Hyper Text Transfer Prot ocol ( HTTP) e t a s e ot oco ( )

  ‡

  XML m essaging dan encoding/ decoding „

  Bagian ini bert anggung j aw ab unt uk Bagian ini bert anggung j aw ab unt uk m e n ge n code / m e n de code m e ssa ge dalam form at XML sehingga m essage dapat dim engert i dan dipert ukarkan. dim engert i dan dipert ukarkan

  „ Prot okol/ Service I nt eract ion yang ada di WS Layer WS Layer ‡

  Service descript ion S i d i t i „

  Bagian ini bert anggung j awab unt uk m e n de sk r ipsik a n

  p pu blic in t e r fa ce sesuai dengan web service yang g y g spesifik.

  „

  Bagian ini dihandle m elalui Service Descript ion: Web Service Descript ion Language ( WSDL) dan XML Schem a p g g ( )

  ‡ Service discovery

  „

  Bagian ini bert anggung j awab unt uk m e n gu m pu lk a n

  se se r vice s k e da la m com m on r e gist r y da n ice s k e da la m com m on e gist da n m e n ye dia k a n k e m u da h a n u n t u k m e m pu blik a sik a n in t e r fa ce da n k e m u da h a n da la m pe n ca r ia n m e t h od. m e t h od „

  Bagian ini dihandle oleh Service Direct ory: Universal HTTP GET dan POST TT G T d ST ‡

  GET: param et er besert a nilai yang GET t b t il i dikirim kan ke server m erupakan bagian dari URL yang panj angnya t erbat as dari URL yang panj angnya t erbat as

  ‡ Cont oh PHP:

  G T Batas GET ‡

  I E: 2.083 charact ers ‡

  

Firefox: 65.536 charact ers

‡

  

Safari: 80.000 charact ers

‡

  Opera: 190 000 charact ers ‡

  Opera: 190.000 charact ers ‡

  

Apache: 4.000 charact ers

‡

  I I S: 16.384 charact ers ‡

  Recom m ended: Maks 2.000

  TT G T d ST HTTP GET dan POST ‡

  Disim pan di c: \ apache\ ht docs dengan nam a cobaget .php ‡

  TELNET: TT G T d ST HTTP GET dan POST

HTTP GET dan POST TT G T d ST ‡

  

POST: param et er dan nilai yang dikirim kan ke

server adalah m erupakan bagian dari m essage body dokum en, karena it u ukurannya j auh lebih body dokum en karena it u ukurannya j auh lebih besar ( def: 2MB ) . Biasanya digunakan dalam sebuah form .

  ‡ Dengan file php yang sam a:

  TT G T d ST HTTP GET dan POST

  Pondasi Web Service d b S

  

WS Architecture WS Architecture

  Service Requestor (Client) Service Requestor (Client) ‡ ‡

  M e n gide n t ifik a si da n m e n e m u k a n se r vice yang relevan sesuai M e n gide n t ifik a si da n m e n e m u k a n se r vice yang relevan sesuai dengan aplikasi yang ada. Biasanya dilakukan dengan pencarian t erhadap UD D I Business Direct ory yang berisi service- service yang ada.

  ‡

Set elah m endapat kan service yang diinginkan, langkah selanj ut nya

adalah m e n ca r i se r vice de scr ipt ion . Bisa berupa WSDL at aupu XML- RPC inst ruct ion

  ‡ M e m bu a t clie n t a pplica t ion . Kit a dapat m em buat XML- RPC at au SOAP client sesuai dengan bahasa pem rogram an yang kit a sukai. Jika SOAP client sesuai dengan bahasa pem rogram an yang kit a sukai. Jika

service ini m em iliki file WSDL, kit a j uga m em iliki opsi unt uk secara

ot om at is m em buat program client m enggunakan WSDL invocat ion t ool.

  ‡ Ja la n k a n clie n t a pplica t ion yang kit a buat dan in vok e t he web service i

  Service Provider (Server) Service Provider (Server) ‡ ‡

  Kem bangkan Kem bangkan fu n gsi- fu n gsi u t a m a dari service. Biasanya ini fu n gsi fu n gsi u t a m a dari service Biasanya ini m erupakan bagian yang paling sulit , sepert i m isalnya koneksi dat abase, EJB, COM, dan lain- lain

  ‡

Kem bangkan sebuah se r vice w r a ppe r unt uk fungsi- fungsi ut am a

t ersebut dalam bent uk XML RPC at au SOAP service t ersebut dalam bent uk XML- RPC at au SOAP service wrapper/ funct ion/ m et hod.

  ‡ Kit a harus m enyediakan se r vice de scr ipt ion . Jika kit a m em buat SOAP

service kit a harus m em buat file WSDL. Jika kit a m em buat XML- RPC

service, kit a harus m em buat hum an readable inst ruct ions unt uk service, kit a harus m em buat hum an- readable inst ruct ions unt uk int egrasi.

  ‡

D e ploy t h e se r vice . Kit a dapat m enyesuaikan dengan kebut uhan,

apakah diinst al at au berj alan dalam server st andalone at au d diint egrasikan dengan w eb server yang t elah ada. t eg as a de ga eb se e ya g t e a ada

  ‡ Kit a harus m e m pu blik a sik a n keberadaan dan spesifikasi service yang t elah kit a buat . Biasanya dapat dilakukan dengan cara m em publikasikan ke global UDDI direct ory at au privat e UDDI direct ory.

  Service Broker / Service Registry Service Broker / Service Registry ‡

  The service brokers allow service providers t o publish t heir services ( r e gist e r , sa ve , a n d ca t e gor iz e ) . They provide also m echanism s t o locat e services and t heir providers XML-RPC C ‡

  XML- RPC is an at t em pt t o im plem ent convent ional Rem ot e Procedure Call ( RPC)

concept s using XML t o t ransm it t he RPC inform at ion XML-RPC C ‡

  Client m enent ukan prosedur dan

param et er yang akan diinvoke ke dalam

  XML request , sedangkan server akan m eresponse „

ent ah it u fault at au success di dalam XML

response

  ‡ Dikem bangkan t ahun 1998 oleh UserLand Soft ware ( ( ht t p: / / www.xm lrpc.com p p ) )

  ‡ Diikut i oleh Apache dan Sun

  Request example POST / RPC2 HTTP/ 1.1 POST / RPC2 HTTP/ 1 1 User- Agent : Front ier/ 5.1.2 ( WinNT)

  The Header Host : cis69.dyndns.com Cont ent - Type: t ext / xm l Cont ent - Type: t ext / xm l Cont ent - lengt h: 144

  < ?xm l version= " 1.0" ?> < m et hodCall> t h dC ll

  < m et hodNam e> exam ples.nam e< / m et hodNam e> < param s> p

  < param > < value> < int > 41< / int > < / value>

  < / param > < / param > < / param s>

  examples.name(41)

  < / m et hodCall>

  Request Example (again) l ) POST /RPC2 HTTP/1.1 User-Agent: Frontier/5.1.2 (WinNT) Host: betty.userland.com Content-Type: text/xml Content Type: text/xml Content-length: 181 <?xml version="1.0"?> <methodCall> <methodName>Calculator.add</methodName> <params> <param> <value><int>41</int></value> </param> <param> <value><int>41</int></value> </param> <param> <value><int>17</int></value> </param> </params> </methodCall> • A User- Agent and Host m ust be specified.

  

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  <Value> l ‡

  Sem ua t ipe dat a t ersebut harus diapit oleh elem ent < value> ... < / value>

  

Array (2) A )

  Struct S

  XML-RPC Request Structure C S ‡

  

Set iap request t erdiri XML, dim ana root S t i t t di i XML di t

elem ennya adalah < m e t h odCa ll> .

  „

Set iap elem en < m et hodCall> t erdiri dari S t i l < t h dC ll> t di i d i

elem en < m et hodNam e> yang dapat berisi elem en < param s> . p

  ‡ Elem en < m e t h odN a m e > m endefinisikan nam a prosedur yang dipanggil sem ent ara p y g p gg

< pa r a m s> berisi daft ar param et er dan

nilainya, set iap param s t erdiri dari elem en- elem en < l l pa r a m > yang j uga t erdiri dari elem en < va lu e >

  Pengiriman Parameter Array g y Here's an example of a response to an XML- RPC request: RPC HTTP/ 1.1 200 OK Connect ion: close Connect ion: close Cont ent - Lengt h: 134 Cont ent - Type: t ext / xm l Dat e: Fri, 17 Jul 1998 19: 55: 08 GMT D F i 17 J l 1998 19 55 08 GMT Server: UserLand Front ier/ 5.1.2- WinNT

  “Luton, LU1 3JU” ,

  < ?xm l version= " 1.0" ?> < m et hodResponse>

  < param s> p < param >

  < value> < st ring> Lut on, LU1 3JU< / st ring> < / value> < / param > < / param >

  < / param s> < / m et hodResponse>

  Response format Response format ‡ ‡

  Unless t here s a low er- level error, alw ays ret urn Unless t here's a lower- level error alw ays ret urn 2 0 0 OK. 2 0 0 OK ‡ t e x t / x m l. Cont ent - Lengt h m ust be present

  The Cont ent - Type is and correct .

  ‡ The body of t he response is a single XML st ruct ure, a Th b d f t h i i l XML t t < m e t h odRe spon se > , which can cont ain a single < pa r a m s> which cont ains a single < pa r a m > which cont ains a single < < va lu e > . va lu e >

  ‡ The < m e t h odRe spon se > could also cont ain a < fa u lt > w hich cont ains a < va lu e > which is a < st r u ct > cont aining t wo elem ent s, one nam ed fa u lt Code , an < int > and one nam ed fa u lt St r in g, a d f lt C d i t d d f lt St i < st ring> .

  < ?xm l version= " 1.0" ?>

  Fault example

  < ?xm l version 1.0 ?> < m et hodResponse>

  < fault > l

  faultCode: 4

  < value> < st ruct >

  < m em ber>

  faultString: Overflow

  < nam e> fault Code< / nam e> < value> < int > 4< / int > < / value>

  < / m em ber> < / m em ber> < m em ber>

  < nam e> fault St ring< / nam e> < value> < st ring> Overflow < / st ring> < / value>

  < / m em ber> < / st ruct > < / st ruct >

  < / value> NEXT T ‡

  SOAP dan UDDI