Use the JNDI

This example task shows you how to use WSIF to bind a reference to a Web service, then look up the reference using JNDI.

You access a Web service through information provided in the WSDL document for the service. If you do not know where to find the WSDL document for the service, but you know that it has been registered in a UDDI registry, then you look it up in the registry. Java programs access Java objects and resources in a similar manner, but using a JNDI interface.

The following example shows how, using the Web Services Invocation Framework (WSIF), you can bind a reference to a Web service then look up the reference using JNDI.

 

Usage Scenario

Specifying the argument values for the Web service

The Web service is represented in WSIF by an instance of the org.apache.wsif.naming.WSIFServiceRef class. This simple Referenceable object has the following constructor

public WSIFServiceRef(
        String WSDL,
        String sNS,
        String sName,
        String ptNS,
        String ptName)
{
    [...]
}

In this example

• WSDL is the location of the WSDL file containing the definition of the service.

• sNS is the full namespace for the service definition (you can specify null if only one service is defined in the WSDL file).

• sName is the local name for the service definition (you can specify null if only one service is defined in the WSDL file).

• ptNS is the full namespace for the port type within the service that you want to use (you can specify null if only one port type is available for the service).

• ptName is the local name for the port type (you can specify null if only one port type is available for the service).

For example, if the WSDL file for the Web service is available from the Web address http://localhost/WSDL/Example.WSDL and contains the following service and port type definitions

  <definitions targetNamespace="http://hostname/namespace/example"
               xmlns:abc="http://hostname/namespace/abc"
[...]
    <portType name="ExamplePT">
      <operation name="exampleOp">
        <input name="exampleInput" message="tns:ExampleInputMsg"/>
      </operation>
    </portType>
[...]
    <service name="abc:ExampleService">
[...]          
    </service>
[...]
  </definitions>

You can specify the following argument values for the WSIFServiceRef class...

• WSDL is http://localhost/WSDL/Example.WSDL

• sNS is http://hostname/namespace/abc

• sName is ExampleService

• ptNS is http://hostname/namespace/example

• ptName is ExamplePT

Binding the service using JNDI

To bind the service reference in the naming directory using JNDI, you can use the com.ibm.websphere.naming.JndiHelper class in WAS

[...]
    import com.ibm.websphere.naming.JndiHelper;
    import org.apache.wsif.naming.*;
[...]
    try {
       Context startingContext = new InitialContext();
       WSIFServiceRef ref = new WSIFServiceRef("http://localhost/WSDL/Example.WSDL",
                                               "http://hostname/namespace/abc"
                                               "ExampleService",
                                               "http://hostname/namespace/example",
                                               "ExamplePT");
       JndiHelper.recursiveRebind(startingContext, 
               "myContext/mySubContext/myServiceRef", ref);
    
    }
    catch  NamingException(e) {
       // Handle  error.
    }
[...]

Looking up the service using JNDI

The following code fragment shows the lookup of a service using JNDI

[...]
    try {
[...]
       InitialContext ic = new InitialContext();
       WSIFService myService = 
           (WSIFService) ic.lookup("myContext/mySubContext/myServiceRef");
[...]
    }
    catch  NamingException(e) {
       // Handle error.
    }
[...]

 

See Also

Using complex types
Using WSIF to invoke Web services
Using the WSIF providers
Developing a WSIF service
Interacting with the J2EE container in WAS
Running WSIF as a client

 

---