**上一节说了购物车的生成，本节主要说了在购物车的列表上去结算，从而生成一个未支付的订单，生成的订单默认状态为1，

题目说的BUG是因为所有数据都是通过前端向后端生成的，包括订单的金额。因此是可以通过F12工具进行修改金额。所以说这个商城的订单生成金额是有BUG存在的。所以我们应该在后台通过商品id、数量进行生成金额，不应该在取前端的金额。

购物车的数据都是从redis中取出来的。**

service层：

OrderServiceImpl .java

package cn.tsu.order.e3mall.service.impl;

import java.util.Date;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import cn.tsu.e3mall.dao.TbOrderItemMapper;
import cn.tsu.e3mall.dao.TbOrderMapper;
import cn.tsu.e3mall.dao.TbOrderShippingMapper;
import cn.tsu.e3mall.jedis.JedisClient;
import cn.tsu.e3mall.pojo.TbItem;
import cn.tsu.e3mall.pojo.TbOrderItem;
import cn.tsu.e3mall.pojo.TbOrderShipping;
import cn.tsu.e3mall.utils.E3Result;
import cn.tsu.order.e3mall.pojo.OrderInfo;
import cn.tsu.order.e3mall.service.OrderService;
import cn.tsu.order.e3mall.service.config.OrderConfig;
import cn.tsu.order.e3mall.service.config.UUIDUtils;
/**
 * 订单列表的service
 * @author xiaofeng
 *
 */
@Service
public class OrderServiceImpl implements OrderService{

    @Autowired
    private JedisClient jedisClient;//redis

    @Autowired
    private TbOrderMapper orderMapper;//订单

    @Autowired
    private TbOrderShippingMapper orderShippingMapper;//收件人

    @Autowired
    private TbOrderItemMapper orderItemMapper;//订单中的商品列表

    //创建订单
    @Override
    public E3Result CreateOrder(OrderInfo orderInfo) {
        // 订单生成
        //1.查询redis中是否含有初始值，通过redis生成商品id
        //2.若不含,则创建一个初始值
        if (!jedisClient.exists(OrderConfig.ORDER_ID_KEY_REDIS)) {
            jedisClient.set(OrderConfig.ORDER_ID_KEY_REDIS, OrderConfig.ORDER_ID_REDIS);
        }
        //3.若含有,则初始值加1当做orderId
        String orderId = jedisClient.incr(OrderConfig.ORDER_ID_KEY_REDIS).toString();
        //4.把orderId加入到orderInfo中
        orderInfo.setOrderId(orderId);
        //状态：1、未付款，2、已付款，3、未发货，4、已发货，5、交易成功，6、交易关闭',
        orderInfo.setStatus(1);
        orderInfo.setCreateTime(new Date());
        orderInfo.setUpdateTime(new Date());
        orderMapper.insert(orderInfo);
        //商品生成
        List<TbOrderItem> orderItems = orderInfo.getOrderItems();
        for (TbOrderItem orderItem : orderItems) {
            orderItem.setId(UUIDUtils.date());
            orderItem.setOrderId(orderId);
            orderItemMapper.insert(orderItem);
        }
        //收件人生成
        TbOrderShipping orderShipping = orderInfo.getOrderShipping();
        orderShipping.setOrderId(orderId);
        orderShipping.setCreated(new Date());
        orderShipping.setUpdated(new Date());
        //清除购物车
        jedisClient.del(OrderConfig.CART_REDIS_PRE+orderInfo.getUserId());
        return E3Result.ok(orderId);
    }
}

controller层：

OrderController.java

package cn.tsu.order.e3mall.controller;

import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import cn.tsu.cart.e3mall.service.CartService;
import cn.tsu.e3mall.pojo.TbItem;
import cn.tsu.e3mall.pojo.TbUser;
import cn.tsu.e3mall.utils.E3Result;
import cn.tsu.order.e3mall.pojo.OrderInfo;
import cn.tsu.order.e3mall.service.OrderService;

/**
 * 支付的逻辑controller
 * @author xiaofeng
 *
 */
@Controller
public class OrderController {

    @Autowired
    private CartService cartService;

    @Autowired
    private OrderService orderService;

    @RequestMapping("order/order-cart")
    public String showOrder(HttpServletRequest request) {
        //通过拦截器set的tbuser获取用户
        TbUser tbUser = (TbUser) request.getAttribute("tbUser");
        //获取购物车里的商品
        List<TbItem> cartList = cartService.getCart(tbUser.getId());
        request.setAttribute("cartList", cartList);
        return "order-cart";
    }
    //订单生成
    @RequestMapping("/order/create")
    public String orderCreate(OrderInfo orderInfo ,HttpServletRequest request) {
        TbUser tbUser = (TbUser) request.getAttribute("tbUser");
        orderInfo.setUserId(tbUser.getId());
        orderInfo.setBuyerNick(tbUser.getUsername());
        E3Result e3Result = orderService.CreateOrder(orderInfo);
        request.setAttribute("payment", orderInfo.getPayment());
        request.setAttribute("orderId", e3Result.getData());
        return "success";
    }
}

拦截器LoginInterceptor：

LoginInterceptor.java

package cn.tsu.order.e3mall.interceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.StringUtils;
import org.jboss.netty.util.internal.StringUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import cn.tsu.cart.e3mall.config.OrderConfig;
import cn.tsu.e3mall.pojo.TbUser;
import cn.tsu.e3mall.utils.CookieUtils;
import cn.tsu.e3mall.utils.E3Result;
import cn.tsu.sso.e3mall.service.UserService;
/**
 *登录拦截器
 * @author xiaofeng
 *
 */
public class LoginInterceptor implements HandlerInterceptor{

    @Autowired
    private UserService userService;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {
        String url = request.getRequestURL().toString();
        System.out.println(url);
        //从用户浏览器中获取cookies
        String token = CookieUtils.getCookieValue(request, OrderConfig.USER_LOGIN_TOKEN);
        //若获取不到,则代表没登录,跳转到登录页面,拦截
        if (StringUtils.isBlank(token)) {
            response.sendRedirect(OrderConfig.LOGIN_HEAD+"/page/login?redirect="+url);
            return false;
        }
        //获取到后到redis中查找user信息
        E3Result e3Result = userService.getToken(token);
        //若查不到信息,则代表没登录,跳转到登录页面,拦截
        if (e3Result.getStatus() != 200) {
            response.sendRedirect(OrderConfig.LOGIN_HEAD+"/page/login?redirect="+url);
            return false;
        }
        //若查找到,把user放到request域中
        TbUser tbUser = (TbUser) e3Result.getData();
        request.setAttribute("tbUser", tbUser);
        //放行
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {
        // TODO Auto-generated method stub

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
        // TODO Auto-generated method stub
    }
}

Mysql提供的解决方案：使用binlog进行数据库同步。需要配置mysql。

代码中实现读写分类：

1、可以使用aop实现一个切面。动态切换数据源。需要编程实现。

2、使用数据库中间件实现读写分类，分库分表。

分库分表：

当数据库的表中数据非常大的时候例如上千万条数据。查询性能非常低。可以把一张表保存到不同的数中。

可以使用一个数据库中间件mycat。国产开源项目，前身是cobar项目。

完！！！！