8 soa technisch perspectief

Bas Kruiswijk

Leiden19 May 2010

Service Oriented Architecture

Deel 4 – SOA vanuit technisch perspectief

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Service Oriented Architecture

OverzichtDeel 4: SOA vanuit technisch perspectief

1. Basisconcepten

2. SOA vanuit organisatorisch perspectief

3. Procesbesturing

4. SOA vanuit technisch perspectief

– Service als technisch concept

– Web services

5. De SOA infrastructuur

6. SOA in het ontwerpproces

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Service Oriented Architecture

Services

– From a technical perspective a logical next step followingobject- en component technology

– Broad adoption of (internet)standards for web services

– Platform independant

– Central concept in (almost) alle current software developmentplatforms (for instance the Java and .NET based platforms)

Serviceimplementation

Serviceinterface

Visible service interface description

Invisible, encapsulatedinternal implementation

request

respons

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Service Oriented Architecture

Service

Serviceimplementation

Serviceinterface

Visible service interface description

Invisible, encapsulatedinternal implementation

request

respons

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Service Oriented Architecture

Web services

– Web services are the most common technical implementation of a service

– Web services are not the only possible technical implementation

– Term Web services refers to a collection of standards that coverinteroperability

– Fundamental standards

– XML (eXtensible Markup Language) and XSD (XML Schema Definition)

– HTTP (HyperText Transfer Protocol)

– WSDL (Web Service Definition Language)

– SOAP (Simple Object Access Protocol)

– UDDI (Universal Description, Discovery and Integration)

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Service Oriented Architecture

Fundamental standards for web services (1)HTTP and XML (existed before web services)

Serviceimplementation

Serviceinterface

Visible service interface description

Invisible, encapsulatedinternal implementation

request

respons

XML

XML

HTTP

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Service Oriented Architecture

XML Example<books>

<book><author>Don Box</author><title>Essential XML</title><price>34,95</price>

</book><book>

<author>Linus Torvalds</author><title>Linux for Fun</title><price>34,95</price>

</book></books>

<ClientSuwi><SofiNr>123456789</SofiNr><BankGironr>01982712</BankGironr><TelefoonnrClient>

<Telefoonnr><Netnr>020</Netnr><Abonneenr>4890000</Abonneenr>

</Telefoonnr></TelefoonnrClient>

</ClientSuwi>

– eXtensible Markup Language for data-exchange, -storage and –presentation

– General format, tag-structure

– Most other web services standards (and many others) are based on XML

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Service Oriented Architecture

XML and XSD (XML Schema Definition)Example

– An XML File has a structure

– An XML Schema Definition (XSD) describes this structure

<shiporder orderid="889923"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:noNamespaceSchemaLocation=""""shiporder.xsdshiporder.xsdshiporder.xsdshiporder.xsd"""">>>>

<orderperson>John Smith</orderperson><shipto>

<name>Ola Nordmann</name><address>Langgt 23</address><city>4000 Stavanger</city><country>Norway</country>

</shipto><item>

<title>Empire Burlesque</title><note>Special Edition</note><quantity>1</quantity><price>10.90</price>

</item><item>

<title>Hide your heart</title><quantity>1</quantity><price>9.90</price>

</item></shiporder>

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Service Oriented Architecture

XML and XSD (XML Schema Definition)

<shiporder orderid="889923"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:noNamespaceSchemaLocation=""""shiporder.xsdshiporder.xsdshiporder.xsdshiporder.xsd"""">>>>

<orderperson>John Smith</orderperson><shipto>

<name>Ola Nordmann</name><address>Langgt 23</address><city>4000 Stavanger</city><country>Norway</country>

</shipto><item>

<title>Empire Burlesque</title><note>Special Edition</note><quantity>1</quantity><price>10.90</price>

</item><item>

<title>Hide your heart</title><quantity>1</quantity><price>9.90</price>

</item></shiporder>

<xs:element name="shipto"><xs:complexType><xs:sequence>

<xs:element name="name" type="xs:string"/><xs:element name="address" type="xs:string"/><xs:element name="city" type="xs:string"/><xs:element name="country" type="xs:string"/>

</xs:sequence></xs:complexType>

</xs:element>

<xs:element name="item" maxOccurs="unbounded"><xs:complexType><xs:sequence>

<xs:element name="title" type="xs:string"/><xs:element name="note" type="xs:string" minOccurs="0"/><xs:element name="quantity" type="xs:positiveInteger"/><xs:element name="price" type="xs:decimal"/>

</xs:sequence></xs:complexType>

</xs:element> XML

Part of the XSD

Part of the XSD

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Service Oriented Architecture

XML and XSD (XML Schema Definition)Example

<?xml version="1.0" encoding="ISO-8859-1"?>

<shiporder orderid="889923"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:noNamespaceSchemaLocation="shiporder.xsd"><orderperson>John Smith</orderperson><shipto><name>Ola Nordmann</name><address>Langgt 23</address><city>4000 Stavanger</city><country>Norway</country>

</shipto><item><title>Empire Burlesque</title><note>Special Edition</note><quantity>1</quantity><price>10.90</price>

</item><item><title>Hide your heart</title><quantity>1</quantity><price>9.90</price>

</item></shiporder>

<?xml version="1.0" encoding="ISO-8859-1" ?><xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="shiporder"><xs:complexType><xs:sequence><xs:element name="orderperson" type="xs:string"/><xs:element name="shipto"><xs:complexType><xs:sequence><xs:element name="name" type="xs:string"/><xs:element name="address" type="xs:string"/><xs:element name="city" type="xs:string"/><xs:element name="country" type="xs:string"/>

</xs:sequence></xs:complexType>

</xs:element><xs:element name="item" maxOccurs="unbounded"><xs:complexType><xs:sequence><xs:element name="title" type="xs:string"/><xs:element name="note" type="xs:string" minOccurs="0"/><xs:element name="quantity" type="xs:positiveInteger"/><xs:element name="price" type="xs:decimal"/>

</xs:sequence></xs:complexType>

</xs:element></xs:sequence><xs:attribute name="orderid" type="xs:string" use="required"/>

</xs:complexType></xs:element>

</xs:schema>

Complete XML

Complete XSD

XSD Defines thestructure of every XML

based on it

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Service Oriented Architecture

Fundamental standards for web services (2)WSDL

Serviceimplementation

Serviceinterface

Visible service interface description

Invisible, encapsulatedinternal implementation

request

respons

XML

XML

HTTP

WSDL

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Service Oriented Architecture

WSDLWeb Service Definition Language

– Web Service Definition Language

– Define the service interface for a web service

– Contains all the information needed to call the web service

– Signature (name and paramaters): description of the request and response messages

– Protocal an location: where to find the service, and how to access it

<definitions>

<types>definition of types........

</types>

<message>definition of a message....

</message>

<portType>definition of a port.......

</portType>

<binding>definition of a binding....

</binding>

</definitions>

XSD definitionsused

Possiblerequest and

responsemessages

Interfacesrequest/response

combinations

How tocall it

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Service Oriented Architecture

WSDL exampleA simple Glossary

<message name="getTermRequest"><part name="term" type="xs:string"/>

</message>

<message name="getTermResponse"><part name="value" type="xs:string"/>

</message>

<portType name="glossaryTerms"><operation name="getTerm"><input message="getTermRequest"/><output message="getTermResponse"/>

</operation></portType>

<binding type="glossaryTerms" name="b1"><soap:binding style="document"transport="http://schemas.xmlsoap.org/soap/http" /><operation><soap:operation soapAction="http://example.com/getTerm"/><input><soap:body use="literal"/></input><output><soap:body use="literal"/></output>

</operation></binding>

SOAP actionthat corresponds

to this action

Request message

Response message

InterfaceWhen you send a“getTermRequest”

you get a“getTermResponse” back

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Service Oriented Architecture

Fundamental standards for web services (3)SOAP

Serviceimplementation

Serviceinterface

Visible service interface description

Invisible, encapsulatedinternal implementation

request

respons

XML

XML

HTTP

WSDL

SOAP

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Service Oriented Architecture

SOAPSimple Object Access Protocol

– Simple Object Access Protocol– Call a component’s service by sending

an XML-message

– Based on standard internet technology (HTTP)

– Suitable for Business-to-Business communication: communication between dissimilar systems (often outside your own company)

– Requests and Responses can be sent and received as SOAP messages

<?xml version="1.0"?><soap:Envelopexmlns:soap="http://www.w3.org/2001/12/soap-envelope"soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Header>...</soap:Header>

<soap:Body>...<soap:Fault>...</soap:Fault>

</soap:Body>

</soap:Envelope>

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Service Oriented Architecture

A SOAP messagevan

aan

/ /Beste

Header

Body

Envelope

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Service Oriented Architecture

SOAPExample

<?xml version="1.0"?><soap:Envelopexmlns:soap="http://www.w3.org/2001/12/soap-envelope"soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Body><m:GetPrice xmlns:m="http://www.w3schools.com/prices"><m:Item>Apples</m:Item>

</m:GetPrice></soap:Body>

</soap:Envelope> <?xml version="1.0"?><soap:Envelopexmlns:soap="http://www.w3.org/2001/12/soap-envelope"soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

<soap:Body><m:GetPriceResponse xmlns:m="http://www.w3schools.com/prices"><m:Price>1.90</m:Price>

</m:GetPriceResponse></soap:Body>

</soap:Envelope>

Request

Response

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Service Oriented Architecture

Fundamental standards for web services (4)UDDI

Serviceimplementation

Serviceinterface

Visible service interface description

Invisible, encapsulatedinternal implementation

request

respons

XML

XML

HTTP

WSDL

SOAP

WebServices

Rotterdam

WebServices

Rotterdam

UDDI

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Service Oriented Architecture

Web services

van

aan

van

aan

/ // /BesteBeste

XMLXMLXMLXML message

Inside aSOAPSOAPSOAPSOAP message

Sent overinternet (HTTPHTTPHTTPHTTP)

Described bya WSDLWSDLWSDLWSDLdefinition

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Service Oriented Architecture

Web services protocols

IP

TCP

HTTP

XML

SOAP

Transportprotocol

Applicationprotocol

WSDL

UDDISupportingprotocol

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Service Oriented Architecture

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Bas Kruiswijkbkr@tg.nl

www.twynstragudde.nl