• We now look at using the client side of Axis.
• The instructions that follow are paraphrased from the Axis User's Guide [1].

• Earlier we saw how to obtain the WSDL description of a Web Service.
• Suppose the WSDL for the Web Service offering the ToFahrenheit method has been stored in the file Service1.wsdl.
• Having downloaded and installed Axis, a proxy class for this Web Service can be created using the command:

  0455: java org.apache.axis.wsdl.WSDL2Java Service1.wsdl 
  

• This will create the files:

  Service1.java
  Service1Locator.java
  Service1Soap.java
  Service1SoapStub.java
  

  in the subdirectory com\a\www\webservices.

• The interface Service1 will declare headers for get methods for each port that is listed in the service element of the WSDL.
• In our example, it declares a header for a method called getService1Soap.
• The class Service1Locator is an implementation of this interface.
• So it implements the getService1Soap method.
• This method returns an instance of the proxy class Service1SoapStub.
• This class implements the interface Service1Soap.
• This interface just declares headers for each method that is provided by the Web Service.
• In our example, it just provides the header of the toFahrenheit method.

These interfaces and classes are used in the following Java program:

0456: import java.rmi.              RemoteException;         // ConsoleClient.java
0457: import javax.xml.rpc.         ServiceException;
0458: import com.a.www.webservices. Service1;
0459: import com.a.www.webservices. Service1Soap;
0460: import com.a.www.webservices. Service1Locator;
0461: public class ConsoleClient
0462: {
0463:     public static void main(String[] pArgs)
0464:             throws RemoteException, ServiceException
0465:     {
0466:         double tCentigrade = Double.parseDouble(pArgs[0]);
0467:         System.out.println("Centigrade: " + tCentigrade);
0468:         Service1 tService1 = new Service1Locator();
0469:         Service1Soap tService1Soap = tService1.getService1Soap();
0470:         double tFahrenheit = tService1Soap.toFahrenheit(tCentigrade);
0471:         System.out.println("Fahrenheit: " + tFahrenheit);
0472:     }
0473: }

• This program expects a Centigrade value as an argument on the java command line:

  0474: javac ConsoleClient.java
  0475: java ConsoleClient 0.0
  

• The getService1Soap method creates an instance of the proxy class Service1SoapStub.
• Having created the object, the program applies the toFahrenheit method to the object:

  0470:         double tFahrenheit = tService1Soap.toFahrenheit(tCentigrade);
  

• As with proxy classes in .NET, when a method of an Axis proxy class is called, the code of the method:
  • sends the appropriate SOAP request to the Web Services's site;
  • decodes the XML that is returned by the Web Services's site;
  • returns an appropriate value to the caller of the method.