/**
*
* @param aUrl 网址
* @param aEncode 编码
* @return 返回的HTML代码
* @throws Exception 对外抛出异常
*/
public String getHTML(String aUrl, String aEncode) throws Exception {
    URL url = new URL(aUrl);
    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
    conn.setConnectTimeout(5000);
    conn.setRequestMethod("GET");
    if (conn.getResponseCode() == 200){
      InputStream inputStream = conn.getInputStream();
      ByteArrayOutputStream outStream = new ByteArrayOutputStream();
      byte[] buffer = new byte[1024];
      int len = 0;
      while( (len = inputStream.read(buffer)) != -1){
        outStream.write(buffer, 0, len);
      }
      String htmlStr = new String(outStream.toByteArray(), aEncode);
      inputStream.close();
      outStream.close();
      return htmlStr;
    }
    return null;
}