无法在Android中打开来自Google地图API的流?

当我在Android上使用以下URL在地图上绘制路线时:

StringBuilder urlString = new StringBuilder();   
   urlString.append("http://maps.google.com/maps?f=d&hl=en");  
   urlString.append("&saddr=");  
   urlString.append(src);  
   urlString.append("&daddr=");// to  
   urlString.append(dest);  
   urlString.append("&ie=UTF8&0&om=0&output=kml");

调用UrlConnection.GetInputStream时引发异常。

HttpURLConnection urlConnection=(HttpURLConnection)url.openConnection();
      urlConnection.setRequestMethod("GET");
      urlConnection.setDoOutput(true);
      urlConnection.setDoInput(true);
      urlConnection.connect(); 

      DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
      DocumentBuilder db = dbf.newDocumentBuilder();
      doc = db.parse(urlConnection.getInputStream()); 

新代码:

Document doc=null;

        try
        { 

            String url = getUrl(p, q);
            DocumentBuilderFactory dbfAdd = DocumentBuilderFactory.newInstance();
            DocumentBuilder dbAdd = dbfAdd.newDocumentBuilder();
            doc = dbAdd.parse(url.toString());