How to implement pseudo-static adding html suffix in WordPress

class Rewrite_Inner_Page_Links
{
  var $separator;
  var $post_rule;
 
  function __construct()
  {
    $this->separator = '/page-';
    // (.+?)/([^/]+).html(/[0-9]+)?/?
    $this->post_rule = '(.+?)/([^/]+)(' . $this->separator . '([0-9]+))+.html/?$';
    if (!is_admin() || defined('DOING_AJAX')) :
      add_filter('wp_link_pages_link', array($this, 'inner_page_link_format'), 10, 2); // for inner pages
      add_filter('redirect_canonical', array($this, 'cancel_redirect_for_paged_posts'), 10, 2);
    endif;
    if (is_admin()) :
      add_filter('rewrite_rules_array', array($this, 'pagelink_rewrite_rules'));
    endif;
  }
 
  /**
   * 修改post分页链接的格式
   * @param string $link
   * @param int $number
   * @return string
   */
  function inner_page_link_format($link, $number)
  {
    if ($number > 1)
    {
      if (preg_match(&#39;%<a href=".*\.html/\d*"%&#39;, $link))
      {
        $link = preg_replace("%(\.html)/(\d*)%", $this->separator . "$2$1", $link);
      }
    }
    return $link;
  }
 
  /**
   * 为新的链接格式增加重定向规则,移除原始分页链接的重定向规则，防止重复收录
   *
   * 访问原始链接将返回404
   * @param array $rules
   * @return array
   */
  function pagelink_rewrite_rules($rules)
  {
    $new_rule[$this->post_rule] = &#39;index.php?name=$matches[2]&page=$matches[4]&#39;;
    return $new_rule + $rules;
  }
 
  /**
   * 禁止WordPress将页面分页链接跳转到原来的格式
   * @param string $redirect_url
   * @param string $requested_url
   * @return bool
   */
  function cancel_redirect_for_paged_posts($redirect_url, $requested_url)
  {
    global $wp_query;
    if (is_single() && $wp_query->get(&#39;page&#39;) > 1)
    {
      return false;
    }
    return true;
  }
}
 
new Rewrite_Inner_Page_Links();