14.4.2. Develop a JAX-WS Client Application

Service

Overview

A Service is an abstraction which represents a WSDL service. A WSDL service is a collection of related ports, each of which includes a port type bound to a particular protocol and a particular endpoint address.

Usually, the Service is generated when the rest of the component stubs are generated from an existing WSDL contract. The WSDL contract is available via the WSDL URL of the deployed endpoint, or can be created from the endpoint source using the wsprovide.sh command in the EAP_HOME/bin/ directory.

This type of usage is referred to as the static use case. In this case, you create instances of the Service class which is created as one of the component stubs.

You can also create the service manually, using the Service.create method. This is referred to as the dynamic use case.

Usage

Static Use Case

The static use case for a JAX-WS client assumes that you already have a WSDL contract. This may be generated by an external tool or generated by using the correct JAX-WS annotations when you create your JAX-WS endpoint.

To generate your component stubs, you use the wsconsume.sh or wsconsume.bat script which is included in EAP_HOME/bin/. The script takes the WSDL URL or file as a parameter, and generates multiple of files, structured in a directory tree. The source and class files representing your Service are named CLASSNAME_Service.java and CLASSNAME_Service.class, respectively.

The generated implementation class has two public constructors, one with no arguments and one with two arguments. The two arguments represent the WSDL location (a java.net.URL) and the service name (a javax.xml.namespace.QName) respectively.

The no-argument constructor is the one used most often. In this case the WSDL location and service name are those found in the WSDL. These are set implicitly from the @WebServiceClient annotation that decorates the generated class.

Example 14.19. Example Generated Service Class

@WebServiceClient(name="StockQuoteService", targetNamespace="http://example.com/stocks", wsdlLocation="http://example.com/stocks.wsdl")
public class StockQuoteService extends javax.xml.ws.Service
{
   public StockQuoteService()
   {
      super(new URL("http://example.com/stocks.wsdl"), new QName("http://example.com/stocks", "StockQuoteService"));
   }

   public StockQuoteService(String wsdlLocation, QName serviceName)
   {
      super(wsdlLocation, serviceName);
   }

   ...
}

Dynamic Use Case

In the dynamic case, no stubs are generated automatically. Instead, a web service client uses the Service.create method to create Service instances. The following code fragment illustrates this process.

Example 14.20. Creating Services Manually

URL wsdlLocation = new URL("http://example.org/my.wsdl");
QName serviceName = new QName("http://example.org/sample", "MyService");
Service service = Service.create(wsdlLocation, serviceName);

Handler Resolver

JAX-WS provides a flexible plug-in framework for message processing modules, known as handlers. These handlers extend the capabilities of a JAX-WS runtime system. A Service instance provides access to a HandlerResolver via a pair of getHandlerResolver and setHandlerResolver methods that can configure a set of handlers on a per-service, per-port or per-protocol binding basis.

When a Service instance creates a proxy or a Dispatch instance, the handler resolver currently registered with the service creates the required handler chain. Subsequent changes to the handler resolver configured for a Service instance do not affect the handlers on previously created proxies or Dispatch instances.

Executor

Service instances can be configured with a java.util.concurrent.Executor. The Executor invokes any asynchronous callbacks requested by the application. The setExecutor and getExecutor methods of Service can modify and retrieve the Executor configured for a service.