When trying to access Magento SOAP web services v2 from Android, after some searching on web, I found that ksoap2-android project could be useful to implement SOAP client in android project. (Ksoap2-android is lightweight and efficient SOAP client library for android platform).
Next step was to figure-out how to use it.
After some additional investigation, I found that it is pretty simple to use, when you get used to it once.

First of all, let’s create new Android project, I set it to be for android 2.3.3. After creating new project, we need to download and import ksoap2-android library inside the project and add it to build path.

Ksoap2-android library can be downloaded from here (http://code.google.com/p/ksoap2-android/downloads/detail?name=ksoap2-android-assembly-2.4-jar-with-dependencies.jar&can=2&q=)

When download ksoap2-android-assembly-2.4-jar-with-dependencies.jar, make additional folder inside your android project, call it for example “lib” and paste ksoap2-android-assembly-2.4-jar-with-dependencies.jar there.

After that, right click on pasted file in package explorer (assuming that you are using Eclipse) and choose: Build Path -> Add To Build Path.

Of course, If we want to access Magento web services SOAP API, we need to go to Magento installation’s admin area and under System/Web services/Roles create Role with appropriate resources (for development purpose, we can mark them all), and then System/Web services/Users create new API user.

After that we need to assign roles we created to user in order to make the whole thing work. We will need user-name and apiKey from there to be able to log-in with our SOAP client.

Now, we are ready to start developing out test application.

As I said, this example is for tutorial purposes – only, and it’s not right way to make Http requests from main Activity, but is just for purposes of this article, so we will now write out code inside Main Activity’s onCreate method:

package com.soap.test;
import java.io.IOException;
import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.HttpTransportSE;
import org.xmlpull.v1.XmlPullParserException;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
public class SoapTestActivity extends Activity {
	/** Called when the activity is first created. */
	private static final String NAMESPACE = "urn:Magento";
	private static final String URL = "http://yourhost.com/api/v2_soap/";
	@Override
	public void onCreate(Bundle savedInstanceState) {
		//our code goes here
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
	}
}

Fist we are going to create and set new SoapSerializationEnvelope:

 //...
		try {
			SoapSerializationEnvelope env = new SoapSerializationEnvelope(
					SoapEnvelope.VER11);
			env.dotNet = false;
			env.xsd = SoapSerializationEnvelope.XSD;
			env.enc = SoapSerializationEnvelope.ENC;
		} catch (Exception e) {
			e.printStackTrace();
		}
//...

After that, lets create our request object and assign it to envelope. We are going first to call “login” method to Magento API in order to authenticate and retreive the sessionId.

//...
		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", "mobile");
			request.addProperty("apiKey", "mobile123");
			env.setOutputSoapObject(request);
		} catch (Exception e) {
			e.printStackTrace();
		}
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
	}

Of course, we have to add request parameters to login method, and it’s done with request.addProperty and then assign request object to envelope.
After that, we need to call SOAP method and retrieve result. so, here is complete Activity source code:

package com.soap.test;
import java.io.IOException;
import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.HttpTransportSE;
import org.xmlpull.v1.XmlPullParserException;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
public class SoapTestActivity extends Activity {
	/** Called when the activity is first created. */
	private static final String NAMESPACE = "urn:Magento";
	private static final String URL = "http://yourhost.com/api/v2_soap/";
	@Override
	public 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", "mobile");
			request.addProperty("apiKey", "mobile123");
			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.main);
	}
}

We retrieved session id as can be seen in LogCat window:

After this basic steps, we just have to make SOAP calls same way to other web service methods, and provide retrieved sessionId in each call.

For example, let’s call customerCustomerList method to retrieve list of customers:

package com.soap.test;
import java.io.IOException;
import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.HttpTransportSE;
import org.xmlpull.v1.XmlPullParserException;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
public class SoapTestActivity extends Activity {
	/** Called when the activity is first created. */
	private static final String NAMESPACE = "urn:Magento";
	private static final String URL = "http://yourhost.com/api/v2_soap/";
	@Override
	public 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", "mobile");
			request.addProperty("apiKey", "mobile123");
			env.setOutputSoapObject(request);
			HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);
			androidHttpTransport.call("", env);
			Object result = env.getResponse();
			Log.d("sessionId", result.toString());
			//making call to get list of customers
			String sessionId = result.toString();
			request = new SoapObject(NAMESPACE, "customerCustomerList");
			request.addProperty("sessionId",sessionId );
			env.setOutputSoapObject(request);
			androidHttpTransport.call("", env);
			result = env.getResponse();
			Log.d("Customer List", result.toString());
		} catch (Exception e) {
			e.printStackTrace();
		}
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
	}
}

As we can see in LogCat window, we got customer list object with child objects as response.

If you want to find out what methods in Magento API v2 are available and what parameters should be used for request, just open URL: http://yourhost.com/api/v2_soap/?wsdl=1 and you will see all available methods and their request and response parameters that can be used.

Of course, don’t forget to set android.permission.INTERNET in AndroidManifest.xml file.

Hope that you will find this post helpful in own projects. Cheers!