Customization enables you to modify the way the wsdl2java generates stub code. In particular, it enables you to modify the WSDL-to-Java mapping and to switch on certain features. Here, customization is used to switch on the asynchronous invocation feature. Customizations are specified using a binding declaration, which you define using a jaxws:bindings tag (where the jaxws prefix is tied to the http://java.sun.com/xml/ns/jaxws namespace). There are two alternative ways of specifying a binding declaration:

This section considers only the external binding declaration. The template for a binding declaration file that switches on asynchronous invocations is shown in Example 7.2, “Template for an Asynchronous Binding Declaration”.

<bindings xmlns:xsd="http://www.w3.org/2001/XMLSchema"
          xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
          wsdlLocation="AffectedWSDL"
          xmlns="http://java.sun.com/xml/ns/jaxws">
  <bindings node="AffectedNode">
    <enableAsyncMapping>true</enableAsyncMapping>
  </bindings>
</bindings>

Where AffectedWSDL specifies the URL of the WSDL contract that is affected by this binding declaration. The AffectedNode is an XPath value that specifies which node (or nodes) from the WSDL contract are affected by this binding declaration. You can set AffectedNode to wsdl:definitions, if you want the entire WSDL contract to be affected. The jaxws:enableAsyncMapping element is set to true to enable the asynchronous invocation feature.

For example, if you want to generate asynchronous methods only for the GreeterAsync interface, you could specify <bindings node="wsdl:definitions/wsdl:portType[@name='GreeterAsync']"> in the preceding binding declaration.

Assuming that the binding declaration is stored in a file, async_binding.xml, you can generate the requisite stub files with asynchronous support by entering the following command:

          
            wsdl2java -ant -client -d ClientDir -b async_binding.xml hello_world.wsdl
          
        

When you run wsdl2java, you specify the location of the binding declaration file using the -b option.

After generating the stub code in this way, the GreeterAsync SEI (in the file GreeterAsync.java) is defined as shown in Example 7.3, “Service Endpoint Interface with Methods for Asynchronous Invocations”.

/* Generated by WSDLToJava Compiler. */
package org.apache.hello_world_async_soap_http;

import org.apache.hello_world_async_soap_http.types.GreetMeSometimeResponse;
...

public interface GreeterAsync
{
  public Future<?> greetMeSometimeAsync(
        java.lang.String requestType,
        AsyncHandler<GreetMeSometimeResponse> asyncHandler
    );

    public Response<GreetMeSometimeResponse> greetMeSometimeAsync(
        java.lang.String requestType
    );

    public java.lang.String greetMeSometime(
        java.lang.String requestType
    );
}

In addition to the usual synchronous method, greetMeSometime(), two asynchronous methods are also generated for the greetMeSometime operation: