The wsdl2java Ant Task or wsdl2java command-line tool can be used to create a web service stub.

The following is the code in the build.xml file used for wsdl2java Ant Task.

...
<target name="-pre-compile">
    <antcall target="wsdl2java">
        <param name="wsdl2java.option" 
         value="-gen:client -d ${build.classes.dir}
         -package echo -compile -verbose ${src.conf}/DocLitEchoService.wsdl" />
    </antcall>
</target>
...

Execute the following command to create the stub source code.

wsclient$ ant -pre-compile

When the previous command executes successfully, a web service stub source code is created. The stub source code is compiled under the directory that is specified in the <destDir> element of wsdl2java's build.xml file.

wsclient/build/classes/echo/
                         |
                         +-- DocLitEchoService.java
                         |
                         +-- DocLitEchoService_Impl.java
                         |
                         +-- Echo.java
                         |
                         +-- ... </screen>

The following source files are generated from the example.

The names of the generated Java file and the methods in the Java file are mapped from WSDL. The following are the mappings from WSDL to Java.

This section shows how the four Java classes, created in the previous section, are used to create a web service client.

The following is an example of implementing the web service client, assuming that it is running in the 'wsclient/src/j2se' directory.

package j2se;

import echo.DocLitEchoService_Impl;
import echo.Echo;

public class ProxyClient {
    public static void main(String args[]) {
        ProxyClient client = new ProxyClient();
        client.run();
    }

    public void run() {
        try {
            Echo port = new DocLitEchoService_Impl().getEchoPort();
            String s = port.echoString("JEUS");
            System.out.println("response = " + s);
        } catch (Exception e) {
            e.printStackTrace();
            System.exit(1);
        }
    }
}

In order to compile the 'ProxyClient' code from the previous example, execute the following command from the 'wsclient' directory.

JEUS_HOME/samples/webservice/jaxrpc/from_java/doclit/doclit-client$ ant build

If the compilation is successful, the following compiled class file is created.

JEUS_HOME/samples/webservice/jaxrpc/from_java/doclit/doclit-client/build/classes/j2s
e/ProxyClient.class

Execute the following command from the directory of the Web service client.

JEUS_HOME/samples/webservice/jaxrpc/from_java/doclit/doclit-client$ ant run

This will produce the following result.

Response = JEUS

The JAX-RPC 1.1 API is used to create DII clients. The JEUS JAX-RPC web service fully supports the JAX-RPC 1.1 API. This section will illustrate a simple example of using the JAX-RPC API.

Note that a DII client can only use the RPC-oriented web service invocation. The examples demonstrate how to write a DII client that invokes echoString operation of a RPC-oriented web service called 'RpcEncEchoService'.

To create a DII client:

The following is an example of creating a DII client, assuming that the client file is in the 'C:/wsclient/src' directory.

package j2se;

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

public class DIIClient {
    private static final String NS_XSD = 
        "http://www.w3.org/2001/XMLSchema";
    private static final QName QNAME_XSD_STRING = new QName(NS_XSD, "string");

    public void run() {
        try {
            ServiceFactory factory = ServiceFactory.newInstance();
            String endpoint = "http://localhost:8088/" +
                "RpcEncEchoService/RpcEncEchoService";
            String targetNamespace = "urn:RpcEncService";
            Service service = factory.createService(
                new QName(targetNamespace, "RpcEncService"));
            Call call = service.createCall();

            call.setTargetEndpointAddress(endpoint);
            call.setOperationName(
                new QName(targetNamespace, "echoString"));
            call.addParameter("String_1", QNAME_XSD_STRING, ParameterMode.IN);
            call.setProperty(Call.OPERATION_STYLE_PROPERTY, "rpc");
            call.setProperty(Call.ENCODINGSTYLE_URI_PROPERTY,
                             "http://schemas.xmlsoap.org/soap/encoding/");
            call.setReturnType(QNAME_XSD_STRING);

            String ret = (String)call.invoke(new Object[] { "JEUS" });
            System.out.println("response = " + ret);
        } catch (Exception e) {
            System.err.println(e.toString());
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        DIIClient client = new DIIClient();
        try {
            client.run();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

In order to compile the DII client code, execute the following command from the 'wsclient' directory in the console.

JEUS_HOME/samples/webservice/jaxrpc/from_java/rpcenc/rpcenc-client$ ant build

If the compilation is successful, the following compiled class file is created.

JEUS_HOME/samples/webservice/jaxrpc/from_java/rpcenc/rpcenc-client/build/classes/j2s
e/DIIClient.class

Execute the following command from the directory of the DII client.

JEUS_HOME/samples/webservice/jaxrpc/from_java/rpcenc/rpcenc-client$ ant run

This will produce the following result.

Response = JEUS

Use the following procedures to invoke a service by using WSDL.

WS-I, a standard organization, requires web services to define and follow a basic profile for web service interoperability purposes. The current basic profile 1.0 requires the WSDL to be accessible at all times.

However, when trying to access a service that does not follow the basic profile, WSDL may not be accessible all the time. In such cases, DII (Dynamic Invocation Interface) enables the call object to invoke web services regardless of the state of WSDL. For this, the details including the styles and names of the operations in WSDL must be provided to the call object.

If WSDL is not specified in the client deployment descriptor file, the client program developer can instantiate the call object through an SEI method, as shown in the following.

Call createCall() throws ServiceException;

The following is an example of Java EE client in JSP that invokes a web service by using a call object.

<%@ page language="java" %>
<%@ page import="javax.naming.*" %>
<%@ page import="javax.rmi.*" %>
<%@ page import="java.rmi.RemoteException" %>
<%@ page import="java.util.*" %>

<%@ page import="javax.naming.InitialContext" %>
<%@ page import="javax.xml.rpc.Service" %>
<%@ page import="javax.xml.rpc.Call" %>
<%@ page import="javax.xml.namespace.QName" %>
<%@ page import="javax.xml.rpc.ParameterMode" %>

<%@ page errorPage="/error.html" %>

<%! String msgToSend = "msg_sent_by_jspClient";
    String ret=null;
    String exceptionString="";
%>

<%
    try {
        InitialContext jndiContext = new InitialContext();
        Service service = (Service)jndiContext.lookup(
            "java:comp/env/service/RpcEncEchoService");

        String targetNamespace = "urn:RpcEncService";
        QName operationName = new QName(targetNamespace,"echoString");
        Call call = service.createCall();
        call.setOperationName(operationName);
        call.addParameter("String_1", 
            new QName("http://www.w3.org/2001/XMLSchema", "string"),ParameterMode.IN);
        
        call.setProperty(Call.OPERATION_STYLE_PROPERTY, "rpc");   
        call.setProperty(Call.ENCODINGSTYLE_URI_PROPERTY, 
            "http://schemas.xmlsoap.org/soap/encoding/");

        call.setReturnType(new QName("http://www.w3.org/2001/XMLSchema","string"));
        call.setTargetEndpointAddress("http://localhost:8088/" +
            "RpcEncEchoService/RpcEncEchoService");

        ret = (String)call.invoke(new Object[]{msgToSend});
    } catch (Exception e) {
        exceptionString = e.toString();
        e.printStackTrace();
    }
%>
<%= "Result is "+ret+"......" 
%>

As can be seen in the previous example, the operation name and its parameters are added after the call object has been instantiated. At this point, additional properties, such as the operation and encoding styles, can be configured as in the following.

call.setProperty(Call.OPERATION_STYLE_PROPERTY, “rpc”);
call.setProperty(Call.ENCODINGSTYLE_URI_PROPERTY, 
“http://schemas.xmlsoap.org/soap/encoding/”);

The following is the deployment descriptor file (web.xml) of the previous example.

<?xml version="1.0"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee">
    <servlet>
        <servlet-name>jsp_helloClient</servlet-name>
        <jsp-file>/helloClient.jsp</jsp-file>
        <load-on-startup>0</load-on-startup>
    </servlet>
    <service-ref>
        <service-ref-name>
            service/DocLitEchoService2
        </service-ref-name>
        <service-interface>
            javax.xml.rpc.Service
        </service-interface>
    </service-ref>
</web-app>

Specify the service name, which a JSP client obtains through the JNDI lookup, in the <service-ref-name> element. The service interface is specified as the javax.xml.rpc.Service interface in the <service-interface> element. To invoke web services without WSDL, the settings in the JAX-RPC mapping file specified in the <jaxrpc-mapping-file> element cannot be used.

A Java EE web service client is a single Java EE component that follows its own packaging style.

The following figure shows how to package the JSP client.

WAR
 |
 +-- JSP Client
 |
 +-- WEB-INF
      |
      +-- web.xml (Servlet DD)
      |
      +-- jeus-web-dd.xml (JEUS Specific DD)
      |
      +-- Jax-rpc mapping file
      |
      +-- wsdl
           |
           +-- wsdl file
      |
      +-- classes
           |
           +-- Java class component (SEI, Service Interface..)

The previous example shows how to invoke a web service by deploying the packaged JavaEE client and then invoking the JSP.

If the paths for WSDL file and JAX-RPC mapping file are configured in the <wsdl-file> and <jax-rpc-mapping-file> elements of the webservices.xml file, they do not have to follow the previous structure.