android 取网址的HTML代码

/**
     * 
     * @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;
    }