1. Discovering E-Services Using UDDI in SELF-SERV Quan Z. Sheng, Boualem Benatallah, Rayan Stephan, Eileen Oi-Yan Mak, Yan Q. Zhu School of Computer Science and Engineering The University of New South Wales Sydney, Australia Beijing, 2002

2. Outline SELF-SERV overview Simple Object Access Protocol (SOAP) Web Service Description Language (WSDL) Universal Description, Discovery and Integration (UDDI) Service Discovery Engine in SELF-SERV Conclusion Beijing, 2002

3. SELF-SERV overview SELF-SERV (compoSing wEb accessibLe inFormation & buSiness sERVices) is a framework for dynamic and peer-to-peer provisioning of Web services. SELF-SERV distinguishes three types of services: elementary services, composite services, and service communities. Composite service aggregates multiple Web service, based on statecharts. Service community is a powerful concepts for composing potential large number of dynamic services. Beijing, 2002

4. SELF-SERV overview Architecture Communication Bus User Interface Elementary Service Composite Service Service Community UDDI Registry Service Manager Beijing, 2002

5. SELF-SERV overview Architecture (cont.) Service Manager is registered with service descriptions Pool of Services Elementary services Communities UDDI Registry Composite services is composed of Service Editor Service Deployer Communication Bus Coordinator.1Coordinator.2Coordinator.n Wrapper Legend SELF-SERV SELF-SERV Interface requests/results workflowdatabase applications web-accessible programs Service Discovery Engine C1 C2 C3 CS1 CS2 ES1ES2 ES3 ES4 Beijing, 2002

6. SOAP: Simple Object Access Protocol An XML-based mechanism for exchanging structured data between network applications composes 3 parts –envelope defines a framework for describing what is in a message and how to process it –encoding rules express instances of application-defined data types –a convention represents remote procedure calls and responses. 2 types of messages, Request/Response Beijing, 2002

7. SOAP: an example of a request POST /carRenting HTTP/1.1 Host: www.axac.com Content-Type: text/xml; charset=“utf-8” Content-Length: 127 SOAPAction: “http://www.anywhere.com/rentCar” <SOAP-ENV:Envelope xmlns:SOAP-ENV=“http://schemas.xmlsoap.org/soap/envelope” SOAP-ENV:encodingStyle=“http://schemas.xmlsoap.org/soap/encoding”> Boualem Benatallah 18/05/2002 20/05/2002 Beijing, 2002

8. SOAP: an example of a reply HTTP/1.1 200 OK Content-Type: text/xml; charset=“utf-8” Content-Length: 234 <SOAP-ENV:Envelope xmlns:SOAP-ENV=“http://schemas.xmlsoap.org/soap/envelope” SOAP-ENV:encodingStyle=“http://schemas.xmlsoap.org/soap/encoding”> 234.00 Beijing, 2002

9. WSDL: Web Service Description Language A general purpose XML language for describing interface, protocol bindings and the deployment details of Web services a WSDL document describes how to invoke a service by providing information on –the data being exchanged –the sequence of messages for an operation –the location of the service and –the description of bindings (e.g., SOAP/HTTP) Beijing, 2002

10. WSDL: service description structure Service Implementation Definition Service Implementation Definition Service Port Service Interface Definition Service Interface Definition Binding Port Type Message Type Beijing, 2002

11. WSDL: elements Types: contains the complex data types used in message Messages: defines the input/output parameters of an operation. Port type: defines the operations of a Web service <schema targetNamespace="http://example.com/carRenting.xsd" xmlns="http://www.w3.org/2000/10/XMLSchema"> Beijing, 2002

12. …. WSDL: elements (cont.) Beijing, 2002

13. WSDL: elements (cont.) Binding: describes the protocol, data format, security and other attributes for a particular service interface. Port: an address for a binding Service: a collection of WSDL port elements …... Beijing, 2002

14. UDDI: Universal Description, Discovery and Integration UDDI is a specification that defines a service registry of available Web services Jointly proposed by Microsoft, Ariba and IBM SOAP can be used to query UDDI for services UDDI is defined through an XML schema, identifying 4 core types of information UDDI APIs specification: publishing/discovering (e.g., UDDI4J) Beijing, 2002

15. UDDI: data structure businessEntity businessService bindingTemplate tModel Beijing, 2002

16. UDDI: an example of business registration <businessList generic=“1.0” operator=“Microsoft operator” truncated=“false” xmlns=“urn:uddi-org:api”> Anywhere Ltd all kinds of cars, trucks, motorbikes for renting <serviceInfo businessKey=“ 089B5-ER8-AC09-599CF7” serviceKey=“12FF-2AF3-45FB-09AF7”> carRental …………. Beijing, 2002

17. UDDI: an example of SOAP message acquiring information from the UDDI Registry Anywhere Ltd For details http://www.uddi.org http://www-3.ibm.com/services/uddi For details http://www.uddi.org http://www-3.ibm.com/services/uddi Beijing, 2002

18. Integrating UDDI with WSDL and SOAP SOAP Request WSDL SOAP Response SOAP Request Publish Invoke Find Service Provider Service Requestor SOAP Response SOAP Request WSDL SOAP Response UDDI Registry Service registration and discovery Beijing, 2002

19. Service Discovery Engine in SELF-SERV Service discovery engine facilitates service advertisements and discovery. UDDI, together with WSDL and SOAP are used to implement the discovery engine. IBM Web Service ToolKit (WSTK) 2.4 benefits a lot of the implementation. Beijing, 2002

20. Service Discovery Engine in SELF-SERV (cont.) IBM WSTK is a showcase package for Web service related emerging technologies. It provides several tools. –A lightweight application server called “embedded WebSphere”. –A WSDL generation tool can encapsulate legacy code (e.g., Java classes, COM) as Web services. –The UDDI4J (a Java API) enables operations to UDDI registry. Beijing, 2002

21. Service Discovery Engine in SELF-SERV (cont.) Creating WSDL descriptions for Web services –using IBM WSDL generation tool Deploying and publishing Web service public class publishService{ String serviceDefinitionWSDL=”http://www.cse.unsw.edu.au/SELFSERV/wsdl/carRental.wsdl” String serviceInterfaceWSDL=”http://www.cse.unsw.edu.au/SELF-SERV/wsdl/carRental-interface.wsdl”; String soapRouter=”http://www.cse.unsw.edu.au/soap/servlet/rpcrouter”; String serviceDeployment=”http://www.cse.unsw.ed.au/SELFSERV/ wsdl/deploymentDescriptor.xml”; String inquiryURL=”http://www.cse.unsw.edu.au/services/uddi/inquiryapi”; String publishURL=”https://www.cse.unsw.edu.au/services/uddi/publishapi”; ServiceRegistryProxy srp = new ServiceRegistryProxyinquiryURL, publishURL, username, password); CategoryList spCatList = new CategoryList(); spCatList.addCategory(TModelKeyTable.UNSPSC, ”84121”, TModelKeyTable.UNSPSC_TMODEL_KEY); ServiceProvider sp=new ServiceProvider(“CarRental”, “SELF-SERV service provider example”, spCatList); sp=srp.publish(sp); ServiceInterface si=new ServiceInterface(serviceInterfaceWSDL); si=srp.publish(si); CategoryList sdCatList=new CategoryList(); sdCatList.addCategory(TmodelKeyTable.UNSPSC, “84121”, TmodelKeyTable.UNSPSC_TMODEL_KEY); SOAPServiceDefinition sd=new SOAPServiceDefinition(serviceDefinitionWSDL, sdCatList, serviceDeployment, soapRouter); sd.createServiceManagerProxy().deployService(sd); srp.publish(sp, sd);} A Java code fragment for publishing a Web service Beijing, 2002

22. Service Discovery Engine in SELF-SERV (cont.) A screen snapshot for service registry. Beijing, 2002

23. Service Discovery Engine in SELF-SERV (cont.) Locate a service Execute the service A screen snapshot for service discovery and invocation. Beijing, 2002

24. Conclusion Present the design and implementation of the Service Discovery Engine in SELF-SERV Show how UDDI, WSDL and SOAP complement each other in Web service advertisement and discovery This work is one part of a large research project SELF- SERV. Other works of SELF-SERV have also published in IEEE ICDE02, VLDB2002 etc. Beijing, 2002