Android app crashes when consuming web-service

Question

I am trying to consume web service through android. I use ksoap2 library and follow this example. Whenever I enter data to text field, app crashes. I get the following error:

Process: com.tinyvoice.webservice, PID: 14447
java.lang.VerifyError: org/ksoap2/SoapEnvelope
        at com.tinyvoice.webservice.WebServiceActivity$1.onClick(WebServiceActivity.java:49)

Here is the app from the link:

public class WebServiceActivity extends AppCompatActivity {
/**
 * Called when the activity is first created.
 */
private static String SOAP_ACTION1 = "http://tempuri.org/FahrenheitToCelsius";
private static String SOAP_ACTION2 = "http://tempuri.org/CelsiusToFahrenheit";
private static String NAMESPACE = "http://tempuri.org/";
private static String METHOD_NAME1 = "FahrenheitToCelsius";
private static String METHOD_NAME2 = "CelsiusToFahrenheit";
private static String URL = "http://www.w3schools.com/webservices/tempconvert.asmx?WSDL";

Button btnFar, btnCel, btnClear;
EditText txtFar, txtCel;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_web_service);

    btnFar = (Button) findViewById(R.id.btnFar);
    btnCel = (Button) findViewById(R.id.btnCel);
    btnClear = (Button) findViewById(R.id.btnClear);
    txtFar = (EditText) findViewById(R.id.txtFar);
    txtCel = (EditText) findViewById(R.id.txtCel);

    btnFar.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //Initialize soap request + add parameters
            SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME1);

            //Use this to add parameters
            request.addProperty("Fahrenheit", txtFar.getText().toString());

            //Declare the version of the SOAP request
            SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);

            envelope.setOutputSoapObject(request);
            envelope.dotNet = true;

            try {
                HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);

                //this is the actual part that will call the webservice
                androidHttpTransport.call(SOAP_ACTION1, envelope);

                // Get the SoapResult from the envelope body.
                SoapObject result = (SoapObject) envelope.bodyIn;

                if (result != null) {
                    //Get the first property and change the label text
                    txtCel.setText(result.getProperty(0).toString());
                } else {
                    Toast.makeText(getApplicationContext(), "No Response", Toast.LENGTH_LONG).show();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });

    btnCel.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //same logic for Farenheit 
...
}
}

I am using Android Studio and added ksoap2.jar to libs folder and then added as a library. Thanks

Answer 1

If you're using Android Studio then you have to add

 compile 'com.google.code.ksoap2-android:ksoap2-android:3.1.0'

in dependencies in gradle and also add

repositories {
    maven { url 'https://oss.sonatype.org/content/repositories/ksoap2-android-releases/' }
}

in buildTypes in gradle

As i faced the same issue in past and i got solved by using the above trick.

Also do network related task in background by using AsyncTask