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A Dynamic Invocation Interface (DII) Client Example

With the dynamic invocation interface (DII), a client can call a remote procedure even if the signature of the remote procedure or the name of the service are unknown until runtime.

Because of its flexibility, a DII client can be used in a service broker that dynamically discovers services, configures the remote calls, and executes the calls. For example, an application for an online clothing store might access a service broker that specializes in shipping. This broker would use the Java API for XML Registries (JAXR) to locate the services of the shipping companies that meet certain criteria, such as low cost or fast delivery time. At runtime, the broker uses DII to call remote procedures on the Web services of the shipping companies. As an intermediary between the clothing store and the shipping companies, the broker offers benefits to all parties. For the clothing store, it simplifies the shipping process, and for the shipping companies, it finds customers.

DII HelloClient Listing

Here is the full listing for the HelloClient.java file of the <JWSDP_HOME>/docs/tutorial/examples/jaxrpc/dynamic directory.

package dynamic;

import javax.xml.rpc.Call;
import javax.xml.rpc.Service;
import javax.xml.rpc.JAXRPCException;
import javax.xml.namespace.QName;
import javax.xml.rpc.ServiceFactory;
import javax.xml.rpc.ParameterMode;

public class HelloClient {

    private static String endpoint =
        "http://localhost:8080/dynamic-jaxrpc/dynamic";
    private static String qnameService = "Hello";
    private static String qnamePort = "HelloIF";

    private static String BODY_NAMESPACE_VALUE = 
        "http://dynamic.org/wsdl";
    private static String ENCODING_STYLE_PROPERTY =
        "javax.xml.rpc.encodingstyle.namespace.uri"; 
    private static String NS_XSD = 
        "http://www.w3.org/2001/XMLSchema";
    private static String URI_ENCODING =
         "http://schemas.xmlsoap.org/soap/encoding/";

    public static void main(String[] args) {
        try {

            ServiceFactory factory = 
                ServiceFactory.newInstance();
            Service service = 
                factory.createService(new QName(qnameService));
    
            QName port = new QName(qnamePort);
    
            Call call = service.createCall(port);
            call.setTargetEndpointAddress(endpoint);
    
            call.setProperty(Call.SOAPACTION_USE_PROPERTY, 
                new Boolean(true));
             call.setProperty(Call.SOAPACTION_URI_PROPERTY,"");
            call.setProperty(ENCODING_STYLE_PROPERTY,
               URI_ENCODING);
            QName QNAME_TYPE_STRING = 
                new QName(NS_XSD, "string");
            call.setReturnType(QNAME_TYPE_STRING);


            call.setOperationName(
                new QName(BODY_NAMESPACE_VALUE "sayHello"));
            call.addParameter("String_1", QNAME_TYPE_STRING, 
                ParameterMode.IN);
            String[] params = { "Duke!" };

            String result = (String)call.invoke(params);
            System.out.println(result);

        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}
 

Building and Running the DII Example

Perform the following steps:

1. If you haven't already done so, follow the instructions in Setting Up.
2. Go to the <JWSDP_HOME>/docs/tutorial/examples/jaxrpc/dynamic directory.
3. Type the following commands:

     ant build
     ant deploy
     ant build-dynamic
     ant run
    
   

The client should display the following line:

A dynamic hello to Duke!
 

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This tutorial contains information on the 1.0 version of the Java Web Services Developer Pack.

All of the material in The Java Web Services Tutorial is copyright-protected and may not be published in other works without express written permission from Sun Microsystems.