Android Techniques for Mock Data Source in Activity Unit testing

Question

I'm fairy new to unit testing and I've been learning how to use the jUnit framework for android(using ActivityInstrumentationTestCase2) but I'm having trouble working out how to I inject a mock data source into and activity, example:

in the activiy I have this

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState,R.layout.market_screen);
        ListView products = (ListView)findViewById(R.id.product_list);
        MarketsAdapter adapter = new  MarketsAdapter(this, new ProductDataSource());
        products.setAdapter(adapter);

}

I currently pass a ProductDataSource into the adapter which connects to a webservice to pull in products for the adapter. In my tests I don't want to connect to the webservice. What is the best technique to inject a mock data source into the activity for testing? Should I create the ProductDataSource in an Application instance and then use a MockApplication in my tests to create a mock data source?

Thanks

I solved by doing the following in the test class setUp() method: Grab a reference to the ListView and set the Mock Data Source using setAdapter(MockDataSource). This has to be run on the UI thread.

mActivity = getActivity();
mDataSource = new FakeDataSource();     
mMarketsListView = (ListView)mActivity.findViewById(R.id.product_list);
mActivity.runOnUiThread(
      new Runnable() {
        public void run() {
          mMarketsListView.setAdapter(new MarketsAdapter(mActivity,mDataSource));

        } // end of run() method definition
   } // end of anonymous Runnable object instantiation
); //