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 Java Platform, Enterprise Edition (Java EE) client and a Java API for XML-based remote procedure call (JAX-RPC) client.
The application server supports Web services based on the JAX-WS and JAX-RPC programming models. JAX-WS is a new programming model that simplifies application development through support of a standard, annotation-based model to develop Web services applications and clients. A JAX-RPC client and JAX-WS client can be used in the same module, therefore the online retailer is still able to use its JAX-RPC applications. The application server makes it easy to configure and reuse configurations, so you can seamlessly incorporate new Web services profiles. The JAX-WS standards support interoperable and reliable Web services applications. The online retailer can send messages asynchronously, which means that the messages can communicate reliably even if one of the parties is temporarily offline, busy, or not available. By using these new technologies, the online retailer can be confident that its communication is reliable and reaches its destination while interoperating with other vendors.
The application powering the Web site checks the Plants by WebSphere inventory database. It discovers that the item is not in stock.
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.
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.
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).