Implement Web services based on Web Services for J2EE: WAS ND

Implement Web services based on Web Services for J2EE

Overview
Decide if a Web service implementation benefits your business process.

Overview

This topic introduces you to using Web services that are based on the Web Services for Java 2 platform, Enterprise Edition (J2EE) specification. WebSphere Application Server supports Web services that are developed and implemented based on Web Services for J2EE.

This topic introduces you to using Web services that are based on the Web Services for Java 2 platform, Enterprise Edition (J2EE) specification. WebSphere Application Server supports Web services that are developed and implemented based on Web Services for J2EE. Use Web services when operating across a variety of platforms, including the J2EE 1.4 and non-J2EE platforms.

Implementing Web services applications is an easy way to integrate application systems together within or outside your company's infrastructure that otherwise function as a standalone systems. For example, your customer information database is a standalone application, but you want your accounting application to be able to access the customer data. You can create a web service for the customer database and then enable the accounting application as Web service client. Now, the accounting application can access the customer information. By implementing a Web service, these two applications can share information in an efficient manner.

Because Web services are easily applied to existing applications and information technology assets, new solutions can be deployed quickly and recomposed to address new opportunities. As Web services become more popular, the pool of services grows, promoting development of more robust models of just-in-time application and business integration over the Internet.
To implement Web services applications with WebSphere Application Server:

Plan to use Web services. Review the Enabling Universal Description, Discovery and Integration (UDDI), Web services gateway and Web Services Invocation Framework concepts to learn how these components can make your Web services plan more robust.

(Optional) Migrate existing Web services.

Develop Web services.

Configure Web services deployment descriptors.

Assemble Web services.

Deploy Web services.

Publish the WSDL file.

Develop Web services clients.

Configure Web services client bindings.

Secure Web services.

Tune Web services.

Troubleshoot Web services.

Example

The following is an example of how a business might use Web services.

The owner of a flower shop wants to start receiving orders from customers through the Web. She starts her venture by finding wholesale flower suppliers, pricing their product, and completing contracts for future flower orders.

Using Web services, the flower shop owner can find wholesale flower suppliers. One way she finds new suppliers is to use a UDDI registry to search for potential suppliers. She chooses the suppliers and the registry sends back information on how to contact the flower distributors that meet her criteria.

The flower shop owner can request price lists from each of the suppliers by obtaining a Web Services Description Language (WSDL) file for each potential supplier. The WSDL can be downloaded from the supplier's Web page, received through email, or retrieved from the supplier's UDDI registry entry.

The WSDL describes the procedure call. When using WebSphere Application Server, the procedure call is a Java API for XML-based remote procedure call (JAX-RPC), which helps her get price lists. The WSDL file also specifies the Universal Resource Locator (URL) where the request is to be sent.

The flower shop owner now has to compare the prices she received back from each supplier, decide which suppliers she is going to do business with, and make arrangements for future orders to be filled. The ground work has been laid for the flower shop to sell merchandise through the Web by using Web services to communicate with suppliers for the best prices and complete the ordering processes. The merchandise price lists need to be published to her Web site and she needs to provide a mechanism for customers to order flowers.

The flower supplier's Web services clients are deployed on the flower shop server. When a customer makes a transaction to purchase flowers through the Web, the order is sent to the supplier through JAX-RPC. The supplier responds by sending a confirmation with the order number and shipping date. The suppliers maintain the inventory and the flower shop owner handles billing and customer order management.

Similarly, the flower shop catalog can be composed automatically from the catalogs of all the suppliers. If the supplier ships directly to the customer, the order tracking inquiries can pass directly to the supplier's order tracking system. Web services can also be used by the supplier to send invoices for orders and by the flower shop to pay the supplier's invoices. Processes that previously required forms to be filled out manually, and faxed or mailed, can now be done automatically, saving labor costs for both the flower shop and the supplier.

Using Web services is beneficial because a much larger inventory is made available to the flower shop. There is no merchandise maintenance overhead, but the flower shop can offer their customers products that they otherwise might not have. Selling flowers through the Web increases capital for the flower shop without overhead of another store or money invested into additional product.

For a more detailed scenario, see Web services scenario: Overview which tells the story of a fictional online garden supply retailer named Plants by WebSphere and how they incorporated the Web services concept.

Overview: Online garden retailer Web services scenarios
Web services
Web Services for J2EE
Java API for XML-based remote procedure call (JAX-RPC)
SOAP
SOAP with Attachments API for Java
Service-oriented architecture
Web services approach to a service-oriented architecture
Web services business models supported
Invoking RMI-IIOP Web services using JAX-RPC

Testing Web services-enabled clients

Web services: Resources for learning