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