android - Getting serialization exception while calling SOAP WEB-Service -

i getting serilization error @

androidhttptransport.call(soap_action, envelope); 

here's full code webservice class

public class webservicecall extends asynctask<string, void, void> {       string result = "";      httptransportse androidhttptransport;      public webservicecall() {         // todo auto-generated constructor stub     }      @override     protected void doinbackground(string... urls) {          try {             soap_action = namespace + method_name;              // adding values request object             request = new soapobject(namespace, method_name);              // adding double value request object             propertyinfo weightprop = new propertyinfo();             weightprop.setname("weight");             double w = double.parsedouble(urls[0]);             weightprop.setvalue(w);             weightprop.settype(double.class);             request.addproperty(weightprop);              // adding string value request object             request.addproperty("fromunit", "" + urls[1]);             request.addproperty("tounit", "" + urls[2]);              envelope = new soapserializationenvelope(soapenvelope.ver11);              // can comment line if web service not .net             // one.             envelope.dotnet = true;              envelope.setoutputsoapobject(request);             httptransportse androidhttptransport = new httptransportse(url);             androidhttptransport.debug = true;              try {                  // soap calling webservice                 androidhttptransport.call(soap_action, envelope);                  // got webservice response                 result = envelope.getresponse().tostring();              } catch (exception e) {                 // todo: handle exception                 e.printstacktrace();             }         } catch (exception e) {             // todo: handle exception             e.printstacktrace();         }         return null;     }      @override     protected void onpostexecute(void r) {         setresult(result);     } } 

logcat error

> 04-10 10:25:05.612: w/system.err(919): java.lang.runtimeexception: cannot serialize: 20.0 04-10 10:25:05.612: w/system.err(919):  @ org.ksoap2.serialization.soapserializationenvelope.writeelement(soapserializationenvelope.java:708) 04-10 10:25:05.612: w/system.err(919):  @ org.ksoap2.serialization.soapserializationenvelope.writeproperty(soapserializationenvelope.java:692) 04-10 10:25:05.612: w/system.err(919):  @ org.ksoap2.serialization.soapserializationenvelope.writeobjectbody(soapserializationenvelope.java:661) 04-10 10:25:05.612: w/system.err(919):  @ org.ksoap2.serialization.soapserializationenvelope.writeobjectbody(soapserializationenvelope.java:645) 04-10 10:25:05.612: w/system.err(919):  @ org.ksoap2.serialization.soapserializationenvelope.writeelement(soapserializationenvelope.java:702) 04-10 10:25:05.612: w/system.err(919):  @ org.ksoap2.serialization.soapserializationenvelope.writebody(soapserializationenvelope.java:618) 04-10 10:25:05.612: w/system.err(919):  @ org.ksoap2.soapenvelope.write(soapenvelope.java:198) 04-10 10:25:05.612: w/system.err(919):  @ org.ksoap2.transport.transport.createrequestdata(transport.java:111) 04-10 10:25:05.612: w/system.err(919):  @ org.ksoap2.transport.httptransportse.call(httptransportse.java:119) 04-10 10:25:05.612: w/system.err(919):  @ org.ksoap2.transport.httptransportse.call(httptransportse.java:95) 04-10 10:25:05.622: w/system.err(919):  @ com.postwebservicing.webservicing$webservicecall.doinbackground(webservicing.java:121) 

try this, after u make call add these lines:

soapprimitive response = (soapprimitive) envelope.getresponse();     string resstring=response.tostring();