异常捕获

  rescue_from ActiveRecord::RecordNotFound do |exception|
    render :text => "没有该记录"
  end

  rescue_from ActionController::ActionControllerError do |exception|
    render :text => "没有控制器"
  end

  rescue_from ActionView::ActionView do |exception|
    render :text => "没有该页面"
  end