Web Service Disc overy Using U DDI Registries in SAP Web AS 6.40For si te li cense s and volume sub scriptions, call 1-781-751-8799. 1 Web service discovery is the process of locating a Web service for a service requester. The W eb Service Description (WSD) for the Web service, which is used to describe the Web service, is in a standardized, machine-processabl e format that is typically expressed in Web Services Description Language (WSDL). Given the multitude of Web services created at a given company , and their standardized form, it makes sense to have an open repository (or “registry”) where you can publish Web services you have created, or where you can subscribe to already-existing W eb services that suit your needs. Universal Descript ion, Discovery , and Integration (UDDI) 1 defines the stan- dard for implementing this type of repository , referred to as a UDDI registry. UDDI regis tries are hosted by many organizations, including SAP, Microsoft, and IBM. Because SAP Web AS 6.20 didn’ t offer any UDDI integration features, you had to use an external UDDI client tool to search a UDDI or to manually publish a WSD to a UDDI. However, SAP Web AS 6.40 comes with a range of supporting publish and subscribe features integrated into SAP tools. Publishing a W eb Service to a UDDI Registry In SAP Web AS 6.40, you have two optio ns for publishing a Web service: • Fro m t he Obj ect Nav iga tor (trans act ion SE8 0) via Web service definition 2 maintenance. From the UDDI tab, you can publish the Web service to any UDDI registry that is maintained in the Web Service Discove ry Using UDDI Registries in SAP Web AS 6.40 Authro SUDDIREG transaction. 3 Choose this method when you are only runn ing the ABAP stack. • Fro m W eb s ervice admini str ati on usi ng a UDDI client. 4 Choose this method when you are running both the ABAP and Java stacks and you wan t to use a UDDI client for publishing Web services. With this approach, you use the same tool for publishing ABAP-based and Java-based Web services. In the WSADMIN transaction, you can maintain the address of the UDDI client and whether you want to access the client directly or via Business Server Pages (BS Ps). Follow the menu path GoTo →Administration Settings in the WSADMIN transaction. Although you can go ahead and implement BSP-based access in the uddiclpublis h BSP application, publis hing it via direct access is generally sufficient. Both options support the use of any UDDI registry, either within or external to SAP. Searching for a Web Service to Subscribe to in a UDDI Registry You might also want to locate a particular Web service to subscribe t o. In this case, y ou need to search a UDDI registry . With the SAP tools, you can search any UDDI that is maintained in the UDDI client. You have the following options for searching a UDDI registry: 1 Go to www.uddi.org for more information. 2 A We b service definiti on is specific to SAP and is used in the context of SAP We b AS to ident ify the W eb service wit hin SAP . SAP often refers to a Web service definition as a WSD, which can be a source of confusion because the acronym also stands for Web Service Descriptio n, which is a W3C standard WSDL document that provide s the information a requester needs to call a service. 3 For more information on the SUDDIREG transaction and how to integrate a UDDI regist ry, go to the SAP Help Portal at http://help.sap.com. 4 SAP provides a UDDI cl ient on the SAP Web AS 6.40 Java stack(http://hos t:java-port/udd iclient). This UDDI client provides features for publishing Web services to a UDDI or searching for a Web service on a UDDI. The UDDI client can integrate a range of UDDIs, such as those provided by IBM, Microsoft, and SAP.
