docs: public String tagFile(String input,String sep) {
  		StringBuilder res = new StringBuilder();
  		try {
  			InputStreamReader read = new InputStreamReader(new FileInputStream(
  					input), "utf-8");
  			BufferedReader lbin = new BufferedReader(read);
  			String str = lbin.readLine();
  			while (str != null) {
  				String s = (String) tag(str);
  				res.append(s);
  				res.append("\n");
  				str = lbin.readLine();
  			}
  			lbin.close();
  			return res.toString();
  		} catch (IOException e) {
  			System.out.println("读输入文件错误");
  			e.printStackTrace();
  		}
  		return "";
  
  	}