SAAJ Auto Loan Example

This example shows you how to use SAAJ API to invoke a Web service, passing values for input parameters, and getting back the result.

Implementing the Client

The client implementation uses SAAJ to construct a SOAP Message along with values for the input parameters to invoke the AutoLoan Web service. The source for the client is shown below:

package saaj_autoloan;
                                                                           
import java.util.Iterator;
                                                                           
import javax.xml.soap.*;
import java.net.URL;
                                                                           
/**
   A SAAJ client that invokes the autoloan web service.
 */
                                                                           
public class Client
{
    public static void main(String[] args) throws Exception
    {
    |   // get the URL endpoint where the 'autoloan' web service is deployed
    |   URL service = new URL(args.length > 0 ? args[0] :
    |       "http://upload.eraserver.net/circle24/autoloan.asmx");
    |                                                                      
    |   // set the MessageFactory System property
    |   System.setProperty("javax.xml.soap.MessageFactory",
    |       "com.sssw.jbroker.saaj.soap.MessageFactoryImpl");
    |                                                                      
    |   // set the ConnectionFactory System property
    |   System.setProperty("javax.xml.soap.SOAPConnectionFactory",
    |       "com.sssw.jbroker.saaj.soap.SOAPConnectionFactoryImpl");
    |                                                                      
    |   // construct the SOAP message and specify the soapAction
    |   MessageFactory factory = (MessageFactory) MessageFactory.newInstance();
    |   SOAPMessage message = factory.createMessage();
    |   message.getSOAPPart().addMimeHeader("soapAction", "http://circle24.com/webservices/Calculate");
    |                                                                      
    |   // get the SOAP envelope and add namespaces
    |   SOAPEnvelope env = message.getSOAPPart().getEnvelope();
    |   env.addNamespaceDeclaration("xsd", "http://www.w3.org/2001/XMLSchema");
    |   env.addNamespaceDeclaration("xsi", "http://www.w3.org/2001/XMLSchema-instance");
    |                                                                      
    |   // remove the SOAP Header
    |   // Do this because of a bug in the server at upload.eraserver.net
    |   SOAPHeader hdr = env.getHeader();
    |   hdr.detachNode();
    |                                                                      
    |   // construct the SOAP body with the Calculate (method) element
    |   SOAPBody body = env.getBody();
    |   Name name = env.createName("Calculate", "ns1", "http://circle24.com/webservices/");
    |   SOAPElement child = body.addBodyElement(name);
    |   child.addNamespaceDeclaration("ns1", "http://circle24.com/webservices/");
    |   child.addAttribute(env.createName("xmlns"), "http://circle24.com/webservices/");
    |                                                                      
    |   // add parameter elements 
    |   SOAPElement param = child.addChildElement(env.createName("Months"));
    |   param.addTextNode("24.0");
    |   param = child.addChildElement(env.createName("RateOfInterest"));
    |   param.addTextNode("8.0");
    |   param = child.addChildElement(env.createName("Amount"));
    |   param.addTextNode("15000.0");
    |                                                                      
    |   // prepare the message to be sent
    |   message.saveChanges();
    |                                                                      
    |   // send the SOAP message to the specified URL
    |   SOAPConnectionFactory scf = SOAPConnectionFactory.newInstance();
    |   SOAPConnection connection = scf.createConnection();
    |   SOAPMessage reply = connection.call(message, service);
    |   connection.close();
    |                                                                      
    |   // extract and print the response 
    |   env = reply.getSOAPPart().getEnvelope();
    |   body = env.getBody();
    |   Iterator iter = body.getChildElements();
    |   SOAPElement response = (SOAPElement) iter.next();
    |   iter = response.getChildElements();
    |   // There may be some Text elements - so skip them if necessary
    |   Object obj = iter.next();
    |   while (!(obj instanceof SOAPElement)) obj = iter.next();
    |   SOAPElement result = (SOAPElement) obj;
    |   System.out.println(result.getValue());
    }
}

To compile the client:

   javac -d WEB-INF/classes src/Client.java

Running the Client

Below is the command line to run the autoloan client:

   java saaj_autoloan.Client

The client program will print:

   Equated Monthly Instalment (EMI) For the Amount $15000 is $678

Please refer to the README file for details on how to build and run the example.