Web Services Blake Schernekau March 27 th, 2006

Learning Objectives Understand Web Services Understand Web Services Figure out SOAP and what it is used for Figure out SOAP and what it is used for Learn how to create a WSDL document Learn how to create a WSDL document Know what UDDI is Know what UDDI is

What are Web Services? Modular applications that can be invoked across the internet Modular applications that can be invoked across the internet Perform simple and complex business processes Perform simple and complex business processes Created as a solution to Distributed Computing problems Created as a solution to Distributed Computing problems

What is Distributed Computing? Using multiple systems to perform functions rather than a single system performing it. Using multiple systems to perform functions rather than a single system performing it.

Needs of Distributed Computing Platform Independent Platform Independent Concordance with existing Internet infrastructure as much as possible Concordance with existing Internet infrastructure as much as possible Vendor independence Vendor independence Scalability, both in number and complexity of nodes Scalability, both in number and complexity of nodes

Solution! Protocols for communication Protocols for communication Simple Object Access Protocol (SOAP) Simple Object Access Protocol (SOAP) Web Service Description Language (WSDL) Web Service Description Language (WSDL) Universal Description, Discovery, and Integration (UDDI) Universal Description, Discovery, and Integration (UDDI)

SOAP Simple Object Access Protocol Simple Object Access Protocol Mechanism for transferring data Mechanism for transferring data SOAP messages define and hold information SOAP messages define and hold information Handles data by encoding it on the sender side and decoding it on the receiver side Handles data by encoding it on the sender side and decoding it on the receiver side

SOAP Format

Header Header Holds optional information about the data that wouldn’t be expected in the body Holds optional information about the data that wouldn’t be expected in the body Body Body Where data is defined and stored Where data is defined and stored

SOAP Request

SOAP Response

WSDL Web Service Description Language Web Service Description Language Provide information about how to connect to and query a web service Provide information about how to connect to and query a web service Typical WSDL includes messages, port types, binding style, and service name Typical WSDL includes messages, port types, binding style, and service name

WSDL

Messages Used to pass data Used to pass data Need one for request and one for response Need one for request and one for response

Port Types Defines the operation hat will be performed Defines the operation hat will be performed Assigns input/output Assigns input/output

Binding Defines the protocol for the operation Defines the protocol for the operation Structures how it will interact with the Web Service Structures how it will interact with the Web Service

Service Combines port type and binding style with the address to the Web Service Combines port type and binding style with the address to the Web Service

One More Look

UDDI Universal Description, Discovery, and Integration Registry for Web Services to be published Like a phone book for Web Services

Overview Web Services are independent, self-describing applications that are accessible via the internet Web Services are independent, self-describing applications that are accessible via the internet SOAP is used to transfer data to and from Web Services SOAP is used to transfer data to and from Web Services WSDL is used to define how to connect to a Web Service WSDL is used to define how to connect to a Web Service UDDI is used to find Web Services UDDI is used to find Web Services

Exercises Exercises are located in the XML Wiki textbook under the Web Services section.

Questions?????

The END!