example shows only the final step: sending the XML invoice to the distributor for payment after the order has been shipped and received. Figure 1-5. This Web service processes a complete purchase order.
Understanding Web Services- XML, WSDL, SOAP and UDDI Page 15 The document-oriented style is good for bulk data exchanges Document-oriented interactions often assume that the parties to a Web services conversation have agreed to share a common business document, such as a purchase order, a ship bill, or an invoice. These parties are often identified as trading partners, or collaborating partners. Trading partners also typically agree on a common process flow, or interaction pattern, for exchanging the shared document, such as requiring an acknowledgment on receipt of a purchase order, returning specific status information in reply to an order query, or sending an e-mail alert when an order has been shipped. During the execution of the business process, a complete document might be exchanged. If the document is already held in common, fragments of information required to fill in specific sections of the shared document, such as purchase price or promised delivery date, might be exchanged. Trading-partner agreements determine required interactions In the Skateboots Company example, preseason bulk orders are handled by using purchase orders submitted in batches according to predefined terms and conditions that help the manufacturer plan capacity. During the season, immediate restocking orders are handled by more interactive services that depend on filling orders from available inventory and that can immediately identify back orders. Thus Skateboots.com provides Web services supporting both major types of interaction.
Understanding Web Services- XML, WSDL, SOAP and UDDI Page 16 The two styles map well to synchronous/asynchronous messaging paradigms The Technology of Web Services Programs that interact with one another over the Web must be able to find one another, discover information allowing them to interconnect, figure out what the expected interaction patterns are— a simple request/reply or more complicated process flow?—and negotiate such qualities of service as security, reliable messaging, and transactional composition. Some of these qualities of service are covered in existing technologies and proposed standards, but others are not. In general, the Web services community is working to meet all these requirements, but it's an evolutionary process, much like the Web itself has been. Web services infrastructure and standards are being designed and developed from the ground up to be extensible, such as XML and HTML before them, so that whatever is introduced in the short term can continue to be used as new standards and technologies emerge.
- Fall '19
- Test, Web Services