try to use xfire client to retrieve data from DSS sample

Question

I am going through the RDBMS sample of data service server now. the service is in 'localhost:9763/services/RDBMSSample?wsdl` and works fine. so I want to use a Xfire client to test the service and for further use. here is my code:

    import java.net.URL;
import org.codehaus.xfire.client.Client;


public class CaClient {
    public static void main(String[] args) throws Exception {
        try {
        String s = System.getProperty("java.runtime.version");
        Client client = new Client(new URL("http://***:9763/services/RDBMSSample?wsdl"));
        Object[] results = client.invoke("productsInfo", new Object[]{null});
        System.out.println(results[0]);
        }
        finally {

        }
    }

}

Then, I run this sample code in eclipse but get the following error:

06, 2013 4:16:33  org.codehaus.xfire.transport.http.HttpChannel sendViaClient
SEVERE: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

How can I disable the SSL?