Transcript Windows Communication Foundation

Arhitectura
serviciilor web
Olteanu Ana Cristina
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La inceput…
Interactiunea web traditionala
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Arhitectura distribuita
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Ce este un serviciu web ?
• Un serviciu web este o aplicatie
modulara, auto-descriptiva care poate fi
publicata si accesata prin Internet si
care foloseste un sistem de mesaje
standardizat XML
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Avantaje
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Interoperabilitate
Arhitectura distribuita – reutilizabile
Distribuire usoara intre consumatori
Modularitate
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Tipuri de arhitecturi
• Arhitectura de tip RPC
• Arhitectura de tip REST
Service (pe Server)
Client
Message
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Arhitectura RPC
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Arhitectura de tip RPC
• Remote Procedure Call
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Mod de functionare
• 3 operatii
– Publicare
– Descoperire
– Conectare
• Exemplu : conversie valutara
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Stiva unui serviciu web
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HTTP
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HyperText Transport Protocol
HTTP 1.1
Metode: GET,POST,PUT,DELETE,HEAD,TRACE
Arhitecura RPC foloseste doar
• GET
• POST
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SOAP
• Simple Object Access Protocol\
• Diferentiaza major cele doua arhitecturi
• Complex : mesajul incapsulat intr-un
invelis
• Bazat pe XML
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Transmitere mesaje XML
folosind SOAP
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UDDI
• Universal Description, Discovery and
Integration
– http://www.uddi.org
• Specificatie tehnica pentru a publica si
a gasi servicii web in Internet
• White pages, yellow pages, green
pages
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Exemplu de registru UDDI
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WSDL
• Web Services Definition Language
– http://www.w3.org/TR/wsdl/
• Limbaj bazat pe XML pentru descrirea
interfetei serviciilor web
– Ce face serviciul ( descriere)
– Cum se foloseste serviciul (metodele)
– Unde se gaseste serviciul
Nu depinde de protocolul de pe nivelul inferior.
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Descriere serviciu cu
WSDL(1)
• <definitions name="WeatherService"
targetNamespace="http://www.ecerami.com/wsdl/WeatherServi
ce.wsdl"
xmlns="http://schemas.xmlsoap.org/wsdl/"
xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/">
<message name="getWeatherRequest">
<part name="zipcode" type="xsd:string"/>
</message>
<message name="getWeatherResponse">
<part name="temperature" type="xsd:int"/>
</message>
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Descriere serviciu cu WSDL
(2)
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<binding name="Weather_Binding" type="tns:Weather_PortType">
<soap:binding style="rpc"
transport="http://schemas.xmlsoap.org/soap/http"/>
<operation name="getWeather">
<soap:operation soapAction=""/>
<input>
<soap:body
encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"
namespace="urn:examples:weatherservice"
use="encoded"/>
</input>
<output>
<soap:body
encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"
namespace="urn:examples:weatherservice"
use="encoded"/>
</output>
</operation>
</binding>
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Interactiunea intre acestea
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Arhitectura REST
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Arhitectura REST
• REpresentational State Transfer
• Arhitectura simpla
– HTTP
– XML
– URI
• In REST totul este o resursa
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Concepte REST (1)
• O pagina web: reprezentare a unei
resurse -> de aici si numele
• URI ( Uniform Resource Identifier) :
numele si adresa resursei
• Anumit format impus de cei ce implementeaza
serviciul
• Exemplu :
– http://www.example.com/relationships/Alice;Bob
– http://www.example.com/nextprime/1024 ?1
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Concepte REST (2)
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Metode HTTP
• Get (GET),Create (PUT), Update( POST),
delete (DELETE)
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GET /weatherforecast/02110 HTTP/1.1
POST /weatherforecast HTTP/1.1
PUT /weatherforecast/95101 HTTP/1.1
DELETE /weatherforecast/02110 HTTP/1.1
• SOAP foloseste doar POST si GET
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Exemplu REST
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Interfata uniforma
• Concept de baza in REST
– URI ce respecta reguli : identifica o
resursa
– Clientul documentat
– XML
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Tehnici de implementare
in .NET
• Windows Communication
Foundation(WCF)
• Componentele majore:
- Adresa
- Binding
- Contract
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Concluzii
• Arhitectura distribuita,scalabilitate
• Cele doua arhitecturi: complex vs
simplu
• Arhitectura de tip REST necesita mai
mult efort in partea clientului
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?
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