ITIS 1210 Introduction to WebBased Information Systems Chapter
ITIS 1210 Introduction to Web-Based Information Systems Chapter 25 How. NET and Web Services Work
Introduction § Normally, software must be installed on your computer for you to use it § This means § You have a acquire (buy) a copy § Install it § Learn to use it § Keep it updated (with newer versions) § Can be expensive & frustrating
Introduction § Also means your OS has to be compatible with the software § For most of us this means buying the latest version of Windows § With whatever problems it has § Converting older versions of our software § Learning to use new Windows features
Introduction § Web services § Allows programs to be run remotely via the Internet § Can be delivered automatically to your desktop § These technologies are extremely versatile § Can be used for a wide variety of purposes
Introduction § For example: § Deliver news & weather directly to your desktop § Deliver stock information § Maintain communications between business partners so they can § Exchange information § Buy & sell goods § Provide other services
Introduction § Basically these are modular software components contained within specific Internet communication protocols § Revolutionary because they eliminate need for an OS to run software § The protocols act as a substitute OS to permit these services to run within your browser
Introduction § “Web services” is a misused term § Technically, only those services which use a specific set of protocols and technologies are actually Web services § These include § XML – Extensible Markup Language § Describes the service and its data § SOAP – Simple Object Access Protocol § Web services communication standard
Introduction § These also include § WSDL - Web Services Description Language § UDDI – Universal Description, Discovery and Integration § The Web service itself is software written in Java § Can run on any browser that has Java capabilities § I. e. , almost all of them
Understanding. NET and Web Services § Step 1 – writing the application § Written in Java § For. NET can use Visual Studio. NET § Supports a variety of languages § C#, J#, Visual Basic, C++ § Completed applications are posted to an application server § WSDL (Web Services Description Language) § Used to create a description of the service
Understanding. NET and Web Services § Description includes § What kind of service it is § Keywords associated with the service § What business is hosting it § How to run it § Location (the application server where it runs) § WSDL is an XML syntax for defining Web services § Includes all information necessary for someone to find and run the service
Understanding. NET and Web Services § Using the SOAP communications protocol § The descriptor is published to a Service Registry § The Registry uses UDDI § A group of specifications § Lets companies publish information about themselves and their Web services § Also lets users search that information to find a Web service they want to use
Understanding. NET and Web Services § Using SOAP, users – Service Requestors – search the Registry § The Service Descriptor tells the user § Where to find the Web service and § How to run it § Based on this information the user “binds” to the service and runs it
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