Q:

SoapSerializationEnvelope error in android app code

I am new to Magento SOAP api  , and i am just fetching the session ID by giving the correct user name and API key  in my android application . But i am getting error in this following line .
            androidHttpTransport.call("", env);

I have given Internet Permission to my android code and this is the code i am trying with . and I am using KSoap2 android external JAR file and I have added it to my build path . 
Please help me
public class MainActivity extends Activity {
private static final String NAMESPACE = "urn:Magento";
private static final String URL = "http://127.0.0.1/index.php/api/v2_soap/";
@Override
protected void onCreate(Bundle savedInstanceState) {
    try {
        SoapSerializationEnvelope env = new SoapSerializationEnvelope(
                SoapEnvelope.VER11);
        env.dotNet = false;
        env.xsd = SoapSerializationEnvelope.XSD;
        env.enc = SoapSerializationEnvelope.ENC;
        SoapObject request = new SoapObject(NAMESPACE, "login");
        request.addProperty("username", "cats");
        request.addProperty("apiKey", "sudhir123");
        env.setOutputSoapObject(request);
        HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);
        androidHttpTransport.call("", env);
        Object result = env.getResponse();
        Log.d("sessionId", result.toString());
    } catch (Exception e) {
        e.printStackTrace();
    }
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

}

A:

I got the answer by replacing this 
http://127.0.0.1/index.php/api/v2_soap/";

by
http://machines Ip address/index.php/api/v2_soap/";

and I started to use V2 soap api. Its working fine.

