Creating Service and Client using AXIOM

[Siddharth Bhargava]

Hi All,
I am trying to learn web services and making services and client using the AXIOM model. I am not able to understand the AXIOM code.

    
Code Listing 5: The StockQuoteService Class using AXIOM
 
package samples.quickstart.service.axiom;
 
import javax.xml.stream.XMLStreamException;
import org.apache.axiom.om.OMAbstractFactory;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMFactory;
import org.apache.axiom.om.OMNamespace;
 
import java.util.HashMap;
public class StockQuoteService {
    private HashMap map = new HashMap();
 
    public OMElement getPrice(OMElement element) throws XMLStreamException {
        element.build();
        element.detach();
 
        OMElement symbolElement = element.getFirstElement();
        String symbol = symbolElement.getText();
 
        String returnText = "42";
        Double price = (Double) map.get(symbol);
        if(price != null){
            returnText  = "" + price.doubleValue();
        }
        OMFactory fac = OMAbstractFactory.getOMFactory();
        OMNamespace omNs =
            fac.createOMNamespace("http://axiom.service.quickstart.samples/xsd", "tns");
        OMElement method = fac.createOMElement("getPriceResponse", omNs);
        OMElement value = fac.createOMElement("price", omNs);
        value.addChild(fac.createOMText(value, returnText));
        method.addChild(value);
        return method;
    }
 
    public void update(OMElement element) throws XMLStreamException {
        element.build();
        element.detach();
 
        OMElement symbolElement = element.getFirstElement();
        String symbol = symbolElement.getText();
 
        OMElement priceElement = (OMElement)symbolElement.getNextOMSibling();
        String price = priceElement.getText();
 
        map.put(symbol, new Double(price));
    }
}
 

    
Code Listing 9: The AXIOMClient class using AXIOM
 
package samples.quickstart.clients;
 
import org.apache.axiom.om.OMAbstractFactory;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMFactory;
import org.apache.axiom.om.OMNamespace;
import org.apache.axis2.Constants;
import org.apache.axis2.addressing.EndpointReference;
import org.apache.axis2.client.Options;
import org.apache.axis2.client.ServiceClient;
 
public class AXIOMClient {
 
    private static EndpointReference targetEPR = 
        new EndpointReference("http://localhost:8080/axis2/services/StockQuoteService");
 
    public static OMElement getPricePayload(String symbol) {
        OMFactory fac = OMAbstractFactory.getOMFactory();
        OMNamespace omNs = fac.createOMNamespace("http://axiom.service.quickstart.samples/xsd", "tns");
 
        OMElement method = fac.createOMElement("getPrice", omNs);
        OMElement value = fac.createOMElement("symbol", omNs);
        value.addChild(fac.createOMText(value, symbol));
        method.addChild(value);
        return method;
    }
 
    public static OMElement updatePayload(String symbol, double price) {
        OMFactory fac = OMAbstractFactory.getOMFactory();
        OMNamespace omNs = fac.createOMNamespace("http://axiom.service.quickstart.samples/xsd", "tns");
 
        OMElement method = fac.createOMElement("update", omNs);
 
        OMElement value1 = fac.createOMElement("symbol", omNs);
        value1.addChild(fac.createOMText(value1, symbol));
        method.addChild(value1);
 
        OMElement value2 = fac.createOMElement("price", omNs);
        value2.addChild(fac.createOMText(value2,
                                         Double.toString(price)));
        method.addChild(value2);
        return method;
    }
 
    public static void main(String[] args) {
        try {
            OMElement getPricePayload = getPricePayload("WSO");
            OMElement updatePayload = updatePayload("WSO", 123.42);
            Options options = new Options();
            options.setTo(targetEPR);
            options.setTransportInProtocol(Constants.TRANSPORT_HTTP);
 
            ServiceClient sender = new ServiceClient();
            sender.setOptions(options);
 
            sender.fireAndForget(updatePayload);
            System.err.println("price updated");
            OMElement result = sender.sendReceive(getPricePayload);
 
            String response = result.getFirstElement().getText();
            System.err.println("Current price of WSO: " + response);
 
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
}

Please help me in understanding the service and clients using AXIOM model from the groundup.

Thanks in advance.