Web services scenario: Static inquiry on supplier

Operating Systems: i5/OS
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Web services scenario: Static inquiry on supplier

In this scenario, an online supply retailer turns an application into a Web service for checking the inventory of its main supplier.

Plants by WebSphere is an Internet storefront that sells plants and gardening supplies. The company realizes that its existing Web application can be "wrapped" with Web services programming interfaces. For example, the BackOrderStock session bean can be turned into a SOAP Web services client that interacts with a Supplier Web services application located at the supplier. Specifically, the BackOrderStock session bean functionality is turned into a Web services for J2EE client and a Java API for XML-based remote procedure call (JAX-RPC) client.

Scenario involving static inquiry on supplier

How out of stock items are handled

The following events happen when a customer on the Plants by WebSphere site orders an item that is not available according to the Plants by WebSphere inventory:

Plants by WebSphere checks its own inventory.
The application powering the Web site checks the Plants by WebSphere inventory database. It discovers that the item is not in stock.
Plants by WebSphere uses a Web service to check the supplier inventory.
The application invokes a SOAP client that communicates with a SOAP server at the supplier site to ascertain whether the supplier has the item in stock. The supplier data is sent to Plants by WebSphere.
Plants by WebSphere either obtains the out of stock item, or does not.
If the supplier indicates that the item is in stock, the application powering Plants by WebSphere determines whether to order the item on behalf of the customer. The exchange of data can include checking a price threshold above which Plants by WebSphere will not order the wholesale item. It could also include decision-making information such as how long the supplier requires to deliver the item, or a date that the manufacturer plans to discontinue the item.
Plants by WebSphere notifies its customer of the outcome, as soon as possible.
If the supplier can be consulted quickly enough, Plants by WebSphere does not have to bother its customer with concerns about availability. It simply confirms that the item is available, as though the item is in stock at Plants by WebSphere. If the supplier inventory temporary lacks the item, or Plants by WebSphere opted not to order the item from the supplier, Plants by WebSphere can issue an appropriate response to the customer.

See the Samples Gallery for details about the GreenhouseByWebSphere application, a business to business (B2B) application that uses a message-driven bean (MDB), a stateless session bean, and Java message service (JMS).

Web services technologies used in this scenario

This scenario uses the following Web services technologies.

XML (Extensible Markup Language): XML is used to standardize the exchange of data between Plants by WebSphere and its supplier.
Web Services for J2EE: Web Services for J2EE, also known as JSR-109, defines how J2EE applications create and access Web services.
JAX-RPC: JAX-RPC, also known as JSR-101, defines how Java applications access Web services.
WSDL (Web Services Description Language): WSDL is used to turn the existing application into a Web service, by acting as the interface between the underlying application and other Web-enabled applications.
SOAP: SOAP is the protocol by which the Web service communicates with the supplier over the Internet.