CSE 636 Data Integration

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CSE 636Data Integration
Web Services
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What is a Web Service

• A web service is a network accessible interface
  to application functionality
• Application interoperability across different
  platforms
• Built using standard Internet technologies
• Clients of web services do NOT need to know how
  they are implemented

Network
Web Service
?
?
Application Client
Application Code
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Web Services Related Standards

• Web Services Description Language (WSDL) 1.1
• http//www.w3.org/TR/wsdl (03/01)
• Version 2.0 under development
• Simple Object Access Protocol (SOAP)
• http//www.w3.org/TR/soap/
• Universal Description, Discovery and Integration
  (UDDI)
• http//www.uddi.org/

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Web Service Technology Stack
Web Service Client
Discovery
Shopping web service?
UDDI
WSDL URIs
Web Service
Description
WSDL
WSDL
SOAP/HTTP request
Proxy
Messaging
SOAP/HTTP response
Transport
HyperText Transfer Protocol (HTTP)
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Part 1 Web Service Methods
Web Service Client
Discovery
Shopping web service?
UDDI
WSDL URIs
Web Service
Description
WSDL
WSDL
SOAP/HTTP request
Proxy
Messaging
SOAP/HTTP response
Transport
HyperText Transfer Protocol (HTTP)
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Part 2 Web Service Description
Web Service Client
Discovery
Shopping web service?
UDDI
WSDL URIs
Web Service
Description
WSDL
WSDL
SOAP/HTTP request
Proxy
Messaging
SOAP/HTTP response
Transport
HyperText Transfer Protocol (HTTP)
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Part 3 Proxy to Access Web Service
Web Service Client
Discovery
Shopping web service?
UDDI
WSDL URIs
Web Service
Description
WSDL
WSDL
SOAP/HTTP request
Proxy
Messaging
SOAP/HTTP response
Transport
HyperText Transfer Protocol (HTTP)
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Part 4 Client to Invoke Proxy
Web Service Client
Discovery
Shopping web service?
UDDI
WSDL URIs
Web Service
Description
WSDL
WSDL
SOAP/HTTP request
Proxy
Messaging
SOAP/HTTP response
Transport
HyperText Transfer Protocol (HTTP)
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Data Services Architecture
Web Application Server
Web Service
Web Service Client
WSDL
WSDL
Parameterized XQuery Expressions
ParameterInstantiation
SOAP/HTTP request
SOAP/HTTP response
QueryExecution
QueryResult
XML Database
XML Schema
XML File
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Web Services Definition Language (WSDL)

• Defines services as collections of network
  endpoints
• Consists of abstract definitions
• Types
• Messages
• Port Types Operations
• and concrete implementations
• Bindings
• Services Ports
• Broken into pieces for reuse purposes

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Port Types Operations

• Port Type An abstract set of operations
  supported
• Operation An abstract description of an action
  supported
• ltportType name"AddressBook"gt
• ltoperation name"addEntry"gt
• ltinput message"tnsAddEntryRequest"/gt
• ltoutput message"tnsempty"/gt
• lt/operationgt
• ltoperation name"getAddressFromName"gt
• ltinput message"tnsGetAddressFromNameRequ
  est"/gt
• ltoutput message"tnsGetAddressFromNameRes
  ponse"/gt
• lt/operationgt
• lt/portTypegt
• Programming languages refer to a port type as a
  class, and to an operation as a method

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Messages

• Abstract, typed definitions of the data being
  communicated
• ltmessage name"empty"/gt
• ltmessage name"AddEntryRequest"gt
• ltpart name"address" type"tnsaddress"/gt
• lt/messagegt
• ltmessage name"GetAddressFromNameRequest"gt
• ltpart name"name" element"tnsentryName"/gt
• lt/messagegt
• ltmessage name"GetAddressFromNameResponse"gt
• ltpart name"address" type"tnsaddress"/gt
• lt/messagegt

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Types

• Data type definitions using the XML Schema type
  system
• lttypesgt
• ltxsschema targetNamespace"urnAddressFetcher
  "
• xmlnsxs"http//www.w3.org/1999/X
  MLSchema"gt
• ltxselement name"entryName"
  type"xsstring"/gt
• ltxscomplexType name"address"gt
• ltxsallgt
• ltxselement name"streetNum"
  type"xsint"/gt
• ltxselement name"streetName"
  type"xsstring"/gt
• ltxselement name"city"
  type"xsstring"/gt
• ltxselement name"state"
  type"xsstring"/gt
• ltxselement name"zip"
  type"xsint"/gt
• ltxselement name"phoneNumber"
  type"xsint"/gt
• lt/xsallgt
• lt/xscomplexTypegt
• lt/xsschemagt
• lt/typesgt

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WSDL File Structure

• ltdefinitions name"urnAddressFetcher"
• targetNamespace"urnAddressFetcher"
• xmlnstns"urnAddressFetcher"
• xmlnsxs"http//www.w3.org/1999/XMLS
  chema"
• xmlnssoap"http//schemas.xmlsoap.or
  g/wsdl/soap/"
• xmlns"http//schemas.xmlsoap.org/wsd
  l/"gt
• lttypesgtlt/typesgt
• ltmessage name"AddEntryRequest"gtlt/messagegt
• ltportType name"AddressBook"gtlt/portTypegt
• ltbindinggtlt/bindinggt
• ltservicegtlt/servicegt
• lt/definitionsgt

Type Definitions
Message Declarations
Port Type Declarations
Binding Declarations
Service Declaration
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Bindings

• Concrete protocol and data format specifications
  for a particular port type
• ltbinding name"AddressBookSOAPBinding"
  type"tnsAddressBook"gt
• ltsoapbinding
• style"document"
• transport"http//schemas.xmlsoap.org/
  soap/http"/gt
• ltoperation name"getAddressFromName"gt
• ltsoapoperation soapAction""/gt
• ltinputgt
• ltsoapbody use"literal"/gt
• lt/inputgt
• ltoutputgt
• ltsoapbody use"literal"/gt
• lt/outputgt
• lt/operationgt
• lt/bindinggt

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Services Ports

• Port a single endpoint defined as a combination
  of a binding and a network address
• Service a collection of related endpoints
• ltservice name"AddressBookService"gt
• ltport name"AddressBook" binding"tnsAddressB
  ookSOAPBinding"gt
• ltsoapaddress location"http//localhost8
  080/axis/services/AddressBook"/gt
• lt/portgt
• lt/servicegt

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Not Discussed

• Types of operations
• One-way The endpoint receives a message
• Request-response The endpoint receives a
  message, and sends a correlated message
• Solicit-response The endpoint sends a message,
  and receives a correlated message
• Notification The endpoint sends a message
• Alternative Bindings
• HTTP Using GET and POST
• MIME
• SOAP
• RPC-Style Web Services
• UDDI