捕获 ActiveRecord::RecordNotFound 输出 404 页面

class ApplicationController < ActionController::Base
  protect_from_forgery with: :exception

  rescue_from ActiveRecord::RecordNotFound, with: :render_404

  protected
  def render_404
    render(file: "#{Rails.root}/public/404.html", :layout => false, :status => 404)
  end
end