Introduction to WSDL.ppt

1、Introduction to WSDL,presented by Xiang Fu,Source,WSDL 1.1 specification http:/www.w3.org/TR/wsdl WSDL 1.2 working draft http:/www.w3.org/TR/wsdl12/ W3C School Tutorial http:/ is WSDL,Web Service Description Language. An XML language used to describe and locate web services. Written in XML. Describe

2、 functionality of a web service Specify how to access the service (binding protocol, message format, and etc.) Not a W3C standard yet. Version 1.1 released March 2001 Working draft of Version 1.2 released July 2003,Related Standards,Type System: XML Schema Name space: XML namespaces Binding: SOAP, H

3、TTP, MIME and etc.,The Main Structure of WSDL,xschema types a set of operations communication protocols a list of binding and ports ,Types, define types used in message declaration XML Schema, DTD, and etc. XML Schema must be supported by any vendor of WSDL conformant products.,WSDL Messages,The ele

4、ment defines the data elements of an operation. Each messages 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 Ports,The element is the most important WSDL element. It defines a web service, the operations th

5、at can be performed, and the messages that are involved. The defines the connection point to a web service, an instance of . It can be compared to a function library (or a module, or a class) in a traditional programming language. Each operation can be compared to a function in a traditional program

6、ming language.,Operation Types,The request-response type is the most common operation type, but WSDL defines four types:,One-way: The operation can receive a message but will not return a response Request-response:The operation can receive a request and will return a response Solicit-response:The op

7、eration can send a request and will wait for a response Notification:The operation can send a message but will not wait for a response - v 1.2 additionrequest multiple response ,One way and Notification Example,Binding,Binding defines how message are transmitted, and the location of the service., My

8、 first service ,WSDL and UDDI,Description of web service.Discovery of web service?UDDI yellow page.,What is UDDI,UDDI is a platform-independent framework for describing services, discovering businesses, and integrating business services by using the Internet. UDDI stands for Universal Description, D

9、iscovery and Integration UDDI is a directory for storing information about web services UDDI is a directory of web service interfaces described by WSDL,How can UDDI be Used,If the industry published an UDDI standard for flight rate checking and reservation, airlines could register their services int

10、o an UDDI directory. Travel agencies could then search the UDDI directory to find the airlines reservation interface. When the interface is found, the travel agency can communicate with the service immediately because it uses a well-defined reservation interface. (by WSDL),Whats missing?,Quality of

11、service. (how fast, how reliable?) Smart Searching (currently business code match)DAML-S project. DARPA Agent Markup Language for web Services. Describes control flow Quality of service. Support smart discovery of service Ontology based technology. A big dictionary defining the relations between concepts.e.g. vehicle car truck ,Problems,Complex long running web services. Communication infrastructure Asynchronous communication Analysis and verification Automatic composition of complex services.,