We have covered a lot in this chapter. We had an overview of web service concepts and were introduced to the SOAP, UDDI and WSDL standards.

Any Java EE 5 compliant application server implements the JAX-WS 2.0 specification. This defines the mapping between Java and WSDL. A Java web service implementation class, which can either be a Java application or stateless session bean, is known as an endpoint implementation class

There are two ways of creating a Java web service. The top-down approach is to first create a WSDL document and then generate a Java endpoint implementation from the WSDL. The second approach is to first create a Java endpoint implementation class and then generate the corresponding WSDL document. This is known as the bottom-up approach.

Using the bottom-up approach we just need to add a few metadata annotations to a Java application in order to expose it as a web service. We looked at a simple Java application example and examined the corresponding WSDL document...