AsyncTask Returns Error

I have been trying to parse XML files using Asynctask, following [1] and [2] tutorials. I have implemented a class in my Activity as follows:

private class GetRoutes extends AsyncTask<String, Void, String[]> {
        @Override
        protected String[] doInBackground(String... urls) {
          String[] read;
              try{
                RouteReader route = new RouteReader();
                read = route.getRoutes();
            } catch(IOException iox){
                read = new String[1];
                read[0] = getResources().getString(R.string.loading_error);
            } catch(ArrayIndexOutOfBoundsException aiob){
                read = new String[1];
                read[0] = getResources().getString(R.string.loading_error);
            } catch(NullPointerException npe){
                read = new String[1];
                read[0] = getResources().getString(R.string.loading_error);
            }
          return read;
        }

        @Override
        protected void onPostExecute(String[] result) {
          values = result;
        }
      }

This is then called in my onCreate method as new GetRoutes().execute("test");. However, when I try to run this, my app crashes as a result of a NullPointerException (logcat is available here).

Could you please guide me on how I can fix this?

For further reference, my RouteReader class is as follows:

public class RouteReader extends Reader{
public final static String routeURL = 
        "http://webservices.nextbus.com/service/publicXMLFeed?command=routeList&a=ttc";
private Map<String, String> routes;

public RouteReader() 
        throws IOException, ArrayIndexOutOfBoundsException{
    super(new URL(routeURL));
    routes = xmlToMap();
}

public String[] getRoutes(){
    return (String[]) routes.keySet().toArray();
}

public String getRouteNum(String route){
    return routes.get(route);
}

private Map<String, String> xmlToMap() 
        throws IOException, ArrayIndexOutOfBoundsException{
    Map<String, String> data = new HashMap<String, String>();
    String input;
    do{
        input = getReader().readLine();
        if (input.startsWith("<route")){
            String[] read = input.split("\"");
            data.put(read[3], read[1]);
        }
    }while (!input.equals("</body>"));
    return data;
}

}