290 likes | 439 Views
.net Web Services. The future of distributed systems architecture. Bradley Gessler Booze Alan Partner brad@boozealan.com www.boozealan.com/seminar/. Agenda. Before web services Introduction Web service examples Messages Code demonstration Future Assignment. Before Web Services.
E N D
.net Web Services The future of distributed systems architecture Bradley Gessler Booze Alan Partnerbrad@boozealan.comwww.boozealan.com/seminar/
Agenda • Before web services • Introduction • Web service examples • Messages • Code demonstration • Future • Assignment
Before Web Services • Raw Byte Streams • RPC • RMI • DCOM • “Screen Scraping”
Introduction to Web Services • XML based RPC • Interfaces that are defined via XML • Uses messaging scheme • Service Oriented Architecture • Usually HTTP based • Firewall friendly • Can use other channels
Internet XML Web Services • Client invokes XML Web Service • Web Service receives and processes request • Web Service sends client a response
Channels • Protocol used to transmit web service messages • HTTP • SMTP • FTP • MSMQS
Protocols • All standards are based on XML • This has made interoperability possible • Current standards are still evolving • Mature enough for simple enterprise applications • New protocols are evolving to enhance current protocols • Security standards • Transactional standards
SOAP • Simple Object Access Protocol • Used to invoke web services • Send/receive messages to and from web services • Describes the methods, arguments, and results of a method call • Envelopes
WSDL • Web Services Description Language • Describes the interface of the web service • Methods • Arguments • Return Values • Variables • Types • Simple Data structures • Arrays
UDDI • Universal Description, Discovery, and Integration • Web service directory • Not widely implemented
Web Services Examples Real world XML web services
Web Services • Zip Code Web Service • http://www.tilisoft.com/ws/LocInfo/ZipCode.asmx • MapPoint.net • http://www.microsoft.com/mappoint/webservice/default.mspx
Consuming a Web Service Visual Studio.NET Demo
Messages Its a Messaging World
Messages • Packet of meaningful data • SOAP Message • Similar to IM messages work
Synchrony Synchronous & Asynchronous
Synchronous Client Web Service
Asynchronous Client Web Service
Reliability • Unreliable • Messages might not be received • More then one of the same message may be received • Reliable • Idempotency • Make sure your web service methods are idempotent
Creating a Web Service Visual Studio.net Demonstration
Creating a .net Web Service Prerequisites • Required • Web Server • IIS 5.0 or greater • Microsoft .net Framework 1.0 or greater • Recommended • Visual Studio.NET 2002 or better • Other Web Service Platforms • Apache Tomcat, J2EE
Web Service Business Value • Less infrastructure requirements • Developers can focus on solving business problems
Future of Web Services • Enterprise Connectivity • Already used internally by many organizations • Starting to gain acceptance as a way to connect organizations to one another
Service Oriented Architecture • Encapsulate all enterprise applications with web services • Consume web services from various systems and applications for various uses • Extremely flexible, scalable, and interoperable
Future of Web Services • Windows Codename “Longhorn” • “Indigo” • Integrated messaging system • Support Multiple Channels • Web Services • MSMQ • And more… • Abstracts the complexities of web services much like what the Visual Studio.net IDE
Assignment • Consume the zip code web service • http://www.tilisoft.com/ws/LocInfo/ZipCode.asmx • Create a windows form that gets the name of the city based on a zip code given by the user • Display the city of the given zip code to the user
Resources • MSDN • http://msdn.microsoft.com/ • http://msdn.microsoft.com/webservices/ • .net Overview • http://www.microsoft.com/net/ • SOAP Example • http://www.w3schools.com/SOAP/soap_example.asp?output=print