1. Web Services CS 6580

2. Web Services Internet-available services using XML messaging, for computer-computer interaction Not tied to any OS or language Self-describing: public interface published, in XML Discoverable: yellow pages to find services and interface descriptions

3. The “Automated Web” Standards mean lower barrier to application integration, possibly “just-in-time” Application Service Registry Web Server Service Description Web Service 1. Discover services 2. Retrieve Service Description 3. Invoke remote service

4. Protocol Stack Discovery: UDDI Description: WSDL XML messaging: SOAP, XML-RPC, REST Transport: HTTP, SMTP, FTP, BEEP

5. XML-RPC Simple Request: in XML, sent via HTTP POST Reply: XML in HTTP response Sample request (minus HTTP headers)

6. XML-RPC response Response, minus HTTP headers:

7. REST – Representational State Transfer (aka XML/HTTP) Simpler Request: via HTTP GET, parameters in URL Result: XML Ex) Visit http://www.amazon.com/webservices GET /onca/xml?Service=AWSECommerceService&SubscriptionId= 15YAMHAMKKB9NK19SQ82&Operation=ItemSearch&Search Index=SportingGoods&Keywords=golf%20club%20Callaway (send above to webservices.amazon.com port 80 using telnet)

8. SOAP – Simple Object Access Protocol Complex Request and Reply in XML, over various protocols, usually HTTP

9. SOAP – sample request

10. Service Description: WSDL (Web Services Description Language) An XML file containing: Public functions Data types Binding info about protocol to use Address info for service (Extensions for SOAP)

11. Service Discovery: UDDI (Universal Description, Discovery, and Integration of Web Services) UDDI has 2 parts: – A technical spec for a distributed directory of businesses and web services Data stored in XML API for searching – UDDI Business Registry: an implementation of UDDI spec White pages: general info (address, phone no., etc) Yellow pages: classification based on industry,product,etc Green pages: tech info about a web service (SOAP, CORBA, Java RMI)