In Chapter 11, we talked about application clients that call EJBs directly over RMI. Though these are great behind the firewall, they're not as useful when you need to support hundreds of custom clients or integrate with remote partners running non-Java systems. Fortunately, the software industry has defined standard web services protocols that let you expose your applications to the world through XML messages passed over HTTP.
Configuring a web service in OC4J is as simple as adding a few lines to a web-application descriptor. In this chapter, we'll cover the following:
Building and deploying both stateless and stateful web services
Configuring and deploying EJB-based web services
Creating web-service clients ...