code: public static HttpServletResponse getEncodingResponse(
              HttpServletResponse response, String charset) {
          response.setCharacterEncoding(charset);
          response.setContentType("text/html;charset=" + charset);
          return response;
      }
docs: 获取编码后的response
  
  @param response 指定response
  @param charset  指定编码集
  @return 返回编码后的response