购物车显示商品总额，点击结算扣除账户金额

我通过foreach显示每个商品详情，该怎么显示总额并且把它传给action？)

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    Map<String,Integer> shopcar = (Map<String,Integer>)request.getSession().getAttribute("shopcar");
    Set<String> isbns = shopcar.keySet();
    for(String isbn : isbns){
        String value = request.getParameter(isbn);
        shopcar.put(isbn, Integer.parseInt(value));    //更新购物车中的购买数量          
    }
    UserBiz biz = new UserBiz();

    try {

        List<TBook> books = null;
        if(shopcar.keySet().size()>0){
            books = biz.getShopcarData(shopcar.keySet());
        }
        double allPrice = 0;
        for(TBook bk : books){
            int buyCount = shopcar.get(bk.getIsbn());
            bk.setBuyCount(buyCount);          //设置图书数量
            allPrice = allPrice + bk.getPrice()*buyCount;
        }
        request.setAttribute("allPrice", allPrice);
        request.setAttribute("books", books);               
        request.getRequestDispatcher("/main/checkout.jsp").forward(request, response);          
    } catch (Exception e) {
        Log.logger.error(e.getMessage(),e);
        request.setAttribute("msg", "网络异常，请和管理员联系");
        request.getRequestDispatcher("/err/error.jsp").forward(request,response);
    }
}

}

可以在foreach后通过发送ajax请求给后台的action

 $.post("money/totalMoney.action",{totalmoney:totalmoney},function(result){
            $("span").html(result);
  });

点击一下 获取DOM对应的单价数量 +1 再插入到原来位置，，
然后获取（单价*数量） 获取的总额插入到你想要的位置 就显示出来了

再用AJAX传递