Web Service That Returns An Array of Objects With KSOAP

In my previous post, I wrote about an example of passing complex objects with KSOAP. In this post, I will write about returning arrays of objects with KSOAP.
If you want to know how to write a method that returns an array of complex objects, look at this code:

public static Category[] GetAllCategories()
    {
        String MethodName = "GetAllCategories";
        SoapObject response = InvokeMethod(URL,MethodName);
        return RetrieveFromSoap(response);
        
    }

Where the function InvokeMethod is :

public static SoapObject InvokeMethod(String URL,String MethodName)
    {
        SoapObject request = GetSoapObject(MethodName);
        SoapSerializationEnvelope envelope = GetEnvelope(request);
        return  MakeCall(URL,envelope,NAMESPACE,MethodName);
    }

GetSoapObject() and GetEnvelope() are:

public static SoapObject GetSoapObject(String MethodName)
    {
        return new SoapObject(NAMESPACE,MethodName);
    }
    public static SoapSerializationEnvelope GetEnvelope(SoapObject Soap)
    {
        SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
        envelope.dotNet = true;
        envelope.setOutputSoapObject(Soap);
        return envelope;
    }

MakeCall() is :

/**
     * 
     * @param URL - The complete URL where the web service resides 
     * @param Envelope - The envelope to be passed
     * @param NAMESPACE - The web method namespace
     * @param METHOD_NAME - The method name
     * @return - SoapObject containing the resultset
     */
    public static SoapObject MakeCall(String URL, SoapSerializationEnvelope Envelope, String NAMESPACE, String METHOD_NAME)
    {
        AndroidHttpTransport androidHttpTransport = new AndroidHttpTransport(URL);
         try
            {
                androidHttpTransport.call(NAMESPACE + METHOD_NAME, Envelope);
                SoapObject response = (SoapObject)Envelope.getResponse();
                return response;
            }
         catch(Exception e)
         {
             e.printStackTrace();
             
         }
         return null;
    }

KSoap Android Web Service Tutorial With Sample Code

A few months ago I was engaged into working with Android and I wanted to make an application that will communicate with the server via .NET SOAP web services, but I soon found out that I will need a library to do the "donkey work for me". Unfortunately, what Visual Studio was doing for me behind the scenes when importing WSDL document, was not present in Android. That means that, I would either parse the WSDL XML myself, or use an external library. After little search, I came up to KSOAP, which looked like a promising library. But soon I got into lot of trouble to make it work.
Partly because there was no complete tutorial with the WHOLE sample WORKING code for passing complex objects as parameters and/or arrays as return values (read this post for returning arrays of objects with KSOAP ), I spent many hours debugging exceptions which were filled with nulls and poor documentation in first place.

Therefore I decided to publish the code I managed to make it work, so many lives will be saved :-) hopefully. I almost forgot about the idea of publishing my code, but today I got some e-mails from some of the Google groups where I was begging for help when I was developing the Android application. So, tortured developer souls, a complete working code for working with the KSOAP library for Android:

Scenario:
We will assume that we want to write a web service that retrieves the details about a given Category by its Id. So, in .NET, the service signature would be:

[Web Method]
public Category GetCategoryById(Category C);