This project contains a simple "Hello World" SOAP service, and corresponding client, written using JAX-WS.
To build SOAP services with JAX-WS, we first create a Java interface describing the service. In our case, this is se325.example04.server.HelloWorld. It contains a single method that takes a String argument and returns a String. The service and method are annotated with appropriate SOAP annotations, which inform the runtime that this interface describes an RPC SOAP service, and that getHelloWorldAsString() is a web service method.
We then need to implement that interface to provide our service logic - HelloWorldImpl in our case. We also need to tag the implementing class with a @WebService annotation, pointing to the interface which describes the service (i.e. HelloWorld in our case).
Finally, we can publish the service and make it available to clients, using the Endpoint.publish() static method, as demonstrated in HelloWorldPublisher. Here, we describe the host, port, and URL path onto which the service should be published.
Once we run HelloWorldPublisher, we can navigate to http://localhost:10000/ws/hello in the browser. This will show an HTML file describing the service. The page will also include a link to the service's WSDL: http://localhost:10000/ws/hello?wsdl.
Also important to note on the HTML page displayed in the browser is the service name. You'll see a string like this:
Service Name: {http://server.example04.se325/}HelloWorldImplService
We need the service URI (http://server.example04.se325/) and service name (HelloWorldImplService), in addition to the URL above, in order to consume the service from our client.
This info is also available to view in the WSDL, in the targetNamespace and name attributes of the root <definitions> element, respectively. The WSDL also contains a generated description of the service methods available, and their request and response datatypes.
As mentioned above, we need three pieces of information in order to consume our SOAP service: the service URI and name (from the WSDL), and the URL where the WSDL is published.
On line 16 of HelloWorldClient, the call to Service.create() will search the WSDL at the given URL, for the service with the given URI and name (in the supplied QName instance). If found, we can connect to and consume the service. If not, an exception will be thrown.
Then, on line 17, we actually connect to the service, and obtain a reference to it, typed as a HelloWorld implementation. In this way, developers are shielded from having to write the XML inputs and outputs of the service themselves - they can simply use the service as if it were a remote Java object, and let the JAX-WS middleware take care of marshalling / unmarshalling in XML format.