ksoap2 - Cannot serialize issue in KSOAP in android

Question

I am using SOAP services in my application,in that when i am calling SOAP services it throwing some cannot serialization problem:

     SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);           
     SoapObject authentication = new SoapObject(NAMESPACE,"authentication");
     PropertyInfo usrid =new PropertyInfo();
     usrid.setName("LoginID");
     usrid.setValue("sting");
     usrid.setType(String.class);
     authentication.addProperty(usrid);        

     PropertyInfo pass =new PropertyInfo();
     pass.setName("Password");
     pass.setValue("string");
     pass.setType(String.class);
     authentication.addProperty(pass);  

     request.addSoapObject(authentication);

     PropertyInfo nos =new PropertyInfo();
     no.setName("No");
     no.setValue(no);
     no.setType(String.class);
     //authentication.addProperty(no);
     request.addProperty("Str", nos);

     SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
     envelope.setOutputSoapObject(request);
     envelope.dotNet=true;    
     HttpTransportSE androidHttpTransport = new HttpTransportSE(URL); 
     try
     { 
          androidHttpTransport.call(SOAP_ACTION,envelope);
          Object result=(Object)envelope.getResponse(); --------->Here i am getting nullpointer.
          Log.i("myApp",result.toString());         
          System.out.println("subbu="+result.toString());
     }

My request Structure is :

<authentication>
    <LoginID>string</LoginID>
    <Password>string</Password>
</authentication>
<No>string</No>

I am receiving the error message:

java.lang.RuntimeException: Cannot serialize:No:

Answer 1

In my opinion your code should not compile as you are writing:

PropertyInfo nos =new PropertyInfo();
no.setName("No");
no.setValue(no);
no.setType(String.class);
//authentication.addProperty(no);
request.addProperty("Str", nos);

Where you clearly meant:

PropertyInfo nos =new PropertyInfo();
nos.setName("No");
nos.setValue(no);
nos.setType(String.class);
//authentication.addProperty(nos);
request.addProperty("Str", nos);

Anyway, i feel like this is a typo and that in your real code you didn't make this error.
So to answer your question, you should tell which one is the null object. It is not possible to guess it from the code snippet you provided.
Use a breakpoint and run your application in debug mode. Then give info about the null object.
Also, showing your WSDL would be of great help.