【android】 conn.getResponseCode(); 返回-1，没报权限错，原因可能是：

URL url = new URL(urlString);
   conn = (HttpURLConnection) url.openConnection();
    conn.setConnectTimeout(30 * 1000);
    conn.setReadTimeout(30 * 1000);
             conn.setRequestProperty("Range", "bytes=" + downFileSize + "-");
       
             
    
    status = conn.getResponseCode();
    if (status == HttpURLConnection.HTTP_OK
      || status == HttpURLConnection.HTTP_PARTIAL) { 
 
 
没加<uses-permission android:name="android.permission.INTERNET"/>权限