.Net Framework
Information Integration on the WebSpring 2003
February 3, 2003
Wrapper &AgentRunner
Information Integration –Wrapper View
Web
Wrapper &AgentRunnerWeb
Wrapper &AgentRunnerWeb Web
Apache Tomcat
Web Service
Information Integration – Web Services View
Web Service
Web ServiceWeb
Web Server
Glue code
What’s the Difference?
• Web services– Standard protocols, WSDL, SOAP…– “Easy” integration using commercial tools– Restricted to web sites that are web services– Less than 0.01% of web is in web service format
• Wrappers– Can support more web sites compared to web services– Integration using academic tools may be little harder
compared to commercial tools for web services– No standard protocols
Overview
• Web services• Web services protocols• Develop web services• Consume web services
What We Are Not Going to Cover About .Net
• We don’t expect you to become experts at C# or VB.NET
What We Are Going to Cover About .Net
• Develop Web Services• Consume Web Services• Build simple applications with C#, VS.NET
Web Services Defined
• Definition– According to IBM “web services are self-
contained, modular applications that can be described, published, located, and invoked over a network, generally, the world wide web”
– According to Microsoft “a web service is programmable application logic, accessible using standard internet protocols”
Web Services: Major Protocols
• XML• SOAP• WSDL• UDDI
Developing .Net Framework Web Service
Hands on LabCreate Hello World Web ServiceDevelop a simple web service that
sends a message Hello World.
Creating Hello World Web Service
When VS.NET comes up click on new project to beginTip: VS.NET can make machine run really slow, be patient
Creating Hello World Web Service (Cont’d)
Pick Visual C# projects and select ASP.NET Web ServiceTip: Remember the location of your web service, also make sure IIS
is running on the machine.
Creating Hello World Web Service (Cont’d)
You will see the standard VS.NET IDE, click on switch to code view to see the code behind the web service
Creating Hello World Web Service (Cont’d)
Uncomment the four lines that have code for Hello World method.
Developing .Net Framework Web Service
Hands on LabCreate Hello World Web ServiceLet’s See Web Service in Action
Hello World Web Service
• What just happened?– VS.NET created test page for hello world– VS.NET also created WSDL for hello world– VS.NET also enabled hello world to ‘talk’
SOAP, WSDL and XML over HTTP• Why do we care about WSDL?
– WSDL can be used by programs like VS.NET or users to integrate our web service with their apps or web services
Web Services
• Building blocks for building applications that integrate information
Geocoded Restaurant List
with Ratings
Name, Address, Lat, Long, Rating
RatingsRatingGeocoded
Restaurant ListName, Address, Lat, Long
Restaurant List Name, Address
City, State
GeocodeLat, Long
Address
Integrating Web Services Using Visual Studio.Net
Hands on LabCalculator Example
Develop a windows application that accepts two numbers and an
operation and calls appropriate web service to provide the result
Integrating Web Services Using Visual Studio.Net
Hands on LabCalculator Example
Let’s See the Application in Action
Conclusion
• Issues– Web services coverage– Web services discovery– Object identification– Web service content description
• Solutions– Web services discovery
• Directory services, e.g. UDDI– Web service content description
• Resource description framework(RDF), semantic web ??– Object identification
• Active learning techniques ??
Conclusion (Cont’d)
• More information on .Net framework– http://msdn.microsoft.com/library/ click on .Net
development– http://www.gotdotnet.com
• Questions, comments?