用户下单

需求分析：

　　移动端用户将菜品或者套餐加入购物车后，可以点击购物车中的【去结算】按钮，页面跳转到订单确认页面，点击【去支付】按钮则完成下单操作

数据模型：

　　orders:订单表

　　order_detail:订单明细表

梳理交互过程：

　　1、在购物车中点击【去结算】按钮，页面跳到订单确认页面

　　2、在订单确认页面，发送ajax请求，请求服务端或者当前登录用户的默认地址

　　3、在订单确认页面，发送ajax请求，请求服务端获取当前登录用户的购物车数据

　　4、在订单确认页面点击【去支付】按钮，发送ajax请求，请求服务端完成下单操作

package com.itheima.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.toolkit.IdWorker;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.itheima.common.BaseContext;
import com.itheima.common.CustomException;
import com.itheima.entity.*;
import com.itheima.mapper.OrderMapper;
import com.itheima.service.*;
import net.sf.jsqlparser.expression.DateTimeLiteralExpression;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.math.BigDecimal;
import java.time.LocalDateTime;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.stream.Collectors;

@Service
public class OrderServiceImpl extends ServiceImpl<OrderMapper, Orders> implements OrderService {


    @Autowired
    private ShoppingCartService shoppingCartService;

    @Autowired
    private UserService userService;

    @Autowired
    private AddressBookService addressBookService;

    @Autowired
    private OrderDetailService orderDetailService;

    /**
     * 用户下单
     * @param orders
     */
    @Transactional
    @Override
    public void submit(Orders orders) {
        //获取当前用户id
        long userId = BaseContext.getCurrentId();
        //查询当前用户购物车数据
        LambdaQueryWrapper<ShoppingCart> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(ShoppingCart::getUserId, userId);
        List<ShoppingCart> shoppingCarts = shoppingCartService.list(queryWrapper);

        if(shoppingCarts==null || shoppingCarts.size()==0){
            throw new CustomException("购物车为空，不能下单");
        }

        //查询用户数据
        User user = userService.getById(userId);
        //查询地址数据
        AddressBook addressBook = addressBookService.getById(orders.getAddressBookId());
        if(addressBook==null){
            throw new CustomException("用户地址信息有误，不能下单");
        }

        //订单号
        long orderId = IdWorker.getId();

        AtomicInteger amount = new AtomicInteger(0);

        List<OrderDetail> orderDetails = shoppingCarts.stream().map((item) -> {
            OrderDetail orderDetail = new OrderDetail();
            BeanUtils.copyProperties(item, orderDetail);
            orderDetail.setOrderId(orderId);
            amount.addAndGet(item.getAmount().multiply(new BigDecimal(item.getNumber())).intValue());
            return orderDetail;
        }).collect(Collectors.toList());


        //向订单表插入数据，一条数据
        orders.setId(orderId);
        orders.setOrderTime(LocalDateTime.now());
        orders.setCheckoutTime(LocalDateTime.now());
        orders.setStatus(2);
        orders.setAmount(new BigDecimal(amount.get())); //总金额
        orders.setUserId(userId);
        orders.setNumber(String.valueOf(orderId));
        orders.setUserName(user.getName());
        orders.setConsignee(addressBook.getConsignee());
        orders.setPhone(addressBook.getPhone());
        orders.setAddress((addressBook.getProvinceName() == null?"":addressBook.getProvinceName())
                + (addressBook.getCityName() == null?"":addressBook.getCityName())
                + (addressBook.getDistrictName() == null?"":addressBook.getDistrictName())
                + (addressBook.getDetail() == null?"":addressBook.getDetail()));
        this.save(orders);

        //向订单明细表插入数据，多条数据
        orderDetailService.saveBatch(orderDetails);

        //清空购物车数据
        shoppingCartService.remove(queryWrapper);
    }
}

    /**
     * 用户下单
     * @param orders
     * @return
     */
    @PostMapping("/submit")
    public R<String> submit(@RequestBody Orders orders){
        log.info("订单数据：｛｝", orders);
        orderService.submit(orders);
        return R.success("下单成功");
    }