Lecture 6 SOAP WSDL UDDI

Lecture 6

SOAPWSDLUDDI

Chapter 2 2Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and

Michael Huhns

Highlights eXtensible Markup Language (XML) Simple Object Access Protocol

(SOAP) Web Services Description

Language (WSDL) Directory Services Universal Description, Discovery,

and Integration (UDDI)


Michael Huhns

Basic Profile (BP 1.0)

The Web Services Interoperability Organization (WS-I) has specified the following Basic Profile version 1.0: SOAP 1.1 HTTP 1.1 XML 1.0 XML Schema Parts 1 and 2 UDDI Version 2 WSDL 1.1


Michael Huhns

Standards for Web Services

BPEL4WSOWL-S Service

Model

ebXMLCPA

Process and workflow orchestrations

QoS: Service descriptions and bindings

Contracts andagreements

XLANG

WSCL

WSDLebXML

CPP

ebXMLBPSS

XML, DTD, and XML Schema

HTTP, FTP, SMTP, SIP, etc.

SOAPebXML

messaging

OWL

UDDIebXML

Registries

WSCLWSCI

WS-Coordination

WS-AtomicTransaction and WS-BusinessActivity

OWL-S Service Grounding

OWL-S Service Profile

BTP

BPML

Discovery (not selection)

Messaging

Transport

QoS: Conversations

QoS: Choreography

QoS: Transactions

Encoding

WS-Policy

WS-Security

WS-Reliable Messaging

PSL

RDF

SOAP SOAP is acronym for Simple Object Access Protocol SOAP is a communication protocol SOAP is designed to communicate via Internet SOAP can extend HTTP for XML messaging SOAP provides data transport for Web services SOAP can exchange complete documents or call a

remote procedure SOAP can be used for broadcasting a message SOAP is platform and language independent SOAP is the XML way of defining what information

gets sent and how


Michael Huhns


Michael Huhns

SOAP (Simple Object Access Protocol)

Used to exchange messages via HTTP, SMTP, and SIP (Session Initiation Protocol for Internet telephony)

Originally designed for remote-procedure calls (RPC)

Works through firewalls on port 80 Character-based, so easy to encrypt/decrypt

and thus easy to secure Inefficient due to character, not binary, data

and large headers Does not describe bidirectional or n-party

interaction


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Web Services: Basic Architecture

ServiceBroker

ServiceProvider

ServiceRequesto

r

Bind or invoke(SOAP)

Find or discover(UDDI)

Publish or announce(WSDL)

Registry; well-known

Not well-known


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Describing a Service

Namee.g., GetTemperature

Types of Input Parameterse.g., (String, String)

Types of Output Parameterse.g., Integer

SOAP architecture

An Envelope element that identifies the XML document as a SOAP message (mandatory)

A Header element that contains header information (optional)

A Body element that contains call and response information (mandatory)

A Fault element containing errors and status information (optional)


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SOAP Envelope (1) The SOAP envelope indicates the start and the end of the

message.

The SOAP envelope solves the problem of knowing when you're done receiving a message and are ready to process it.

Every SOAP message has a root Envelope element.

Envelope element is mandatory part of SOAP Message.

Every Envelope element must contain exactly one Body element.

If an Envelope contains a Header element, it must contain no more than one, and it must appear as the first child of the Envelope, before the Body.

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SOAP Envelope (2) The envelope changes when SOAP versions change.

The SOAP envelope is specified using the ENV namespace prefix and the Envelope element.

The optional SOAP encoding is also specified using a namespace name and the optional encodingStyle element, which could also point to an encoding style other than the SOAP one.

A v1.1-compliant SOAP processor will generate a fault when receiving a message containing the v1.2 envelope namespace.

A v1.2- compliant SOAP processor generates a VersionMismatch fault if it receives a message that does not include the v1.2 envelope namespace.


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<?xml version="1.0"?>

<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://www.w3.org/2001/12/soap-envelope" SOAP-ENV:encodingStyle="http://www.w3.org/2001/12/soap-encoding">

... Message information goes here ...

</SOAP-ENV:Envelope>


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Michael Huhns

Ex. SOAP Request

POST /temp HTTP/1.1Host: www.socweather.comContent-Type: text/xml; charset="utf-8"Content-Length: xxxSOAPAction: "http://www.socweather.com/temp"

<!—These comments below: an XML document --><?xml version=“1.0”?><env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/" env:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/> <env:Body> <m:GetTemp xmlns:m="http://www.socweather.com/temp.xsd"> <m:City>Honolulu</m:City> <m:When>now</m:When> </m:GetTemp> </env:Body></env:Envelope>


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Ex. SOAP Response

HTTP/1.1 200 OKContent-Type: text/xml; charset="utf-8"Content-Length: xxxSOAPAction: "http://www.socweather.com/temp"

<?xml version="1.0"?><env:Envelope

xmlns:env="http://schemas.xmlsoap.org/soap/envelope/"

env:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>

<env:Body> <m:GetTempResponse

xmlns:m="http://www.socweather.com/temp.xsd"> <m:DegreesCelsius>30</m:DegreesCelsius> </m:GetTempResponse> </env:Body></env:Envelope>

SOAP Fault The SOAP fault mechanism returns specific information about the

error, including a predefined code, a description, the address of the SOAP processor that generated

A SOAP Message can carry only one fault block Fault element is an optional part of SOAP Message For the HTTP binding, a successful response is linked to the 200 to 299

range of status codes; SOAP fault is linked to the 500 to 599 range of status codes.


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Fault example<?xml version='1.0' encoding='UTF-8'?> <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/1999/XMLSchema-instance" xmlns:xsd="http://www.w3.org/1999/XMLSchema"> <SOAP-ENV:Body>

<SOAP-ENV:Fault> <faultcode xsi:type="xsd:string">SOAP-ENV:Client</faultcode> <faultstring xsi:type="xsd:string">

Failed to locate method (ValidateCreditCard) in class (examplesCreditCard) at /usr/local/ActivePerl-5.6/lib/ site_perl/5.6.0/SOAP/Lite.pm line 1555.

</faultstring> </SOAP-ENV:Fault>

</SOAP-ENV:Body> </SOAP-ENV:Envelope>


Michael Huhns

WSDL: Web Services Description Language

Describes a programmatic interface to a Web service, including Definitions of data types Input and output message formats The operations provided by the service Network addresses Protocol bindings

WSDL structure<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>


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A WSDL document describes a web service using these major elements:

Element Defines

<types> The data types used by the web service

<message> The messages used by the web service

<portType> The operations performed by the web service

<binding> The communication protocols used by the web service


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WSDL Ports The <portType> element is the most important WSDL element.

It describes a web service, the operations that can be performed, and the messages that are involved.

The <portType> element can be compared to a function library (or a module, or a class) in a traditional programming language.

WSDL Messages The <message> element defines the data elements of an operation. Each message can consist of one or more parts. The parts can be compared to the

parameters of a function call in a traditional programming language. WSDL Types

The <types> element defines the data types that are used by the web service.

For maximum platform neutrality, WSDL uses XML Schema syntax to define data types.

WSDL Bindings

The <binding> element defines the message format and protocol details for each port.


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WSDL example

<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>


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portType Operations

Type DefinitionOne-way The operation can receive a message but will

not return a responseRequest-response The operation can receive a request and will

return a responseSolicit-response The operation can send a request and will wait

for a responseNotification The operation can send a message but will not

wait for a response


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<?xml version="1.0"?><wsdl:definitions name="Temperature" targetNamespace="http://www.socweather.com/schema" xmlns:ts="http://www.socweather.com/TempSvc.wsdl" xmlns:tsxsd="http://schemas.socweather.com/TempSvc.xsd" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/">



<wsdl:types> <xsd:schema targetNamespace="http://namespaces.socweather.com" xmlns:xsd="http://www.w3.org/1999/XMLSchema">

 <xsd:element name="GetTemp"> <xsd:complexType> <xsd:sequence> <xsd:element name="City" type="string"/> <xsd:element name="When" type="string"/> </xsd:sequence> </xsd:complexType> </xsd:element>

 <xsd:element name="GetTempResponse">  </xsd:element>

 <xsd:element name="GetTempFault">  </xsd:element> </xsd:schema> </wsdl:types>



 <wsdl:message name="GetTempRequest"> <wsdl:part name="body" element="tsxsd:GetTemp"/> </wsdl:message>

 <wsdl:message name="GetTempResponse"> <wsdl:part name="body" element="tsxsd:GetTempResponse"/> </wsdl:message>

 <wsdl:portType name="GetTempPortType">

 <wsdl:operation name="GetTemp"> <wsdl:input message="ts:GetTempRequest"/> <wsdl:output message="ts:GetTempResponse"/> <wsdl:fault message="ts:GetTempFault"/> </wsdl:operation> </wsdl:portType>

 <wsdl:binding name="TempSvcSoapBinding" type="ts:GetTempPortType">

 <soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/>

  <wsdl:operation name="GetTemp"> <soap:operation soapAction="http://www.socweather.com/TempSvc"/> <wsdl:input> <soap:body use="literal" namespace="http://schemas.socweather.com/TempSvc.xsd"/> </wsdl:input>



</wsdl:operation> </wsdl:binding>

 <wsdl:service name="TemperatureService"> <wsdl:documentation>socweather.com temperature service </wsdl:documentation>

 <wsdl:port name="GetTempPort" binding="ts:TempSvcSoapBinding">

 <soap:address location="http://www.socweather.com/TempSvc"/> </wsdl:port> </wsdl:service></wsdl:definitions>


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WSDL Data Model

definitions targetNamespace=thisNamespace xmins:tns=thisNamespace

types message name=in message name=out

portType name=foo operation input message=tns:in output message=tns:out

binding name=foobar type=tns:foo [binding information]

service name=foobar Service

Port name=foobarPort binding=tns:foobar [endpoint information]

Types contains data type definitionsMessages consist of one or more parts

A portType describes an abstract setof operations

A binding describes a concrete set offormats and protocols for the fooportTypes

A port describes an implementationof the foobar binding


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Directory Services Support discovery: enable applications,

agents, Web service providers, Web service requestors, people, objects, and procedures to locate each other White pages – entries found by name Yellow pages – entries found by characteristics

and capabilities A basic directory might be a simple

database (passive) or a broker/facilitator (active, that provides alerts and recruits participants)

UDDI – both white pages and yellow pages, but passive


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UDDI: Universal Description, Discovery, and Integration

UDDI is a Web service that is based on SOAP and XML

UDDI registers tModels: technical descriptions of a

service’s behavior businessEntities: describes the

specifications of multiple tModels


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Yellow, Green, and White Pages in UDDI

-businessKey : string(idl)-name : string(idl)-description : string(idl)-URL : string(idl)-contacts : contact-businessServices : businessService-identifierBag : keyedReference-categoryBag : keyedReference

businessEntity

1

*

-tModelKey : string(idl)-keyName : string(idl)-keyValue : string(idl)

keyedReference

-serviceKey : string(idl)-tModelKey : string(idl)-name : string(idl)-description : string(idl)-bindingTemplates

businessService

-phone : string(idl)-address : string(idl)

contact

businessEntity: Information about theparty who publishes information about

a service

businessService: Descriptiveinformation about a particular family of

technical services

bindingTemplate: Technicalinformation about a service entry point

and implementation specs

tModel: Descriptions of specificationsfor services or value sets. Basis for

technical fingerprints

businessEntities containbusinessServices

businessServices containbindingTemplates

bindingTemplates contain referencesto tModels. These references

designate the interface specificationsfor a service


Michael Huhns

Data Model for UDDI

businessEntity data structure:<businessEntity businessKey="uuid:C0E6D5A8-C446-4f01-99DA-70E212685A40" operator="http://www.ibm.com"

authorizedName="John Doe"> <name>Acme Company</name> <description>

We create cool Web services </description> <contacts>

<contact useType="general info"> <description>General Information</description> <personName>John Doe</personName> <phone>(123) 123-1234</phone>

<email>[email protected]</email> </contact> </contacts> <businessServices> ... </businessServices>

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<identifierBag> <keyedReference tModelKey="UUID:8609C81E-EE1F-4D5A-B202-3EB13AD01823" name="D-U-N-S" value="123456789" /> </identifierBag> <categoryBag>

<keyedReference tModelKey="UUID:C0B9FE13-179F-413D-8A5B-5004DB8E5BB2" name="NAICS" value="111336" /> </categoryBag>

</businessEntity>


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businessService data structure

<businessService serviceKey="uuid:D6F1B765-BDB3-4837-828D-8284301E5A2A"

businessKey="uuid:C0E6D5A8-C446-4f01-99DA-70E212685A40"> <name>Hello World Web Service</name> <description>A friendly Web service</description>

<bindingTemplates> ... </bindingTemplates>

</businessService>


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bindingTemplate


Michael Huhns


Michael Huhns

WSDL UDDI

<import>

<port>

<port>

BusinessEntity

BusinessService

BindingTemplate

BindingTemplate

Service Implementation

UDDI

<service>

Service Interface

<types>

<message>

<portType>

<binding>

tModel

WSDL


Michael Huhns

Chapter 2 Summary

The main triad of Web services standards Bring together well-known ideas

SOAP: object access and messaging WSDL: based on CORBA IDL UDDI: based on directories

Provide necessary functionality for interoperation

Are complicated in their details Meant for tool vendors rather than

programmers Increasingly hidden by tools

Lecture 6 SOAP WSDL UDDI

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