瑞吉外卖项目：移动端购物车功能与用户下单功能开发

一. 购物车功能需求分析

移动端用户可以将菜品或者套餐加入购物车中，对于菜品来说，设置了口味信息，需要选择规格参数方可加入购物车；

对于套餐来说，可以直接点击黄色的加号按钮将套餐加入购物车。同时可以修改菜品与套餐的数量，也可以清空购物车。

购物车所对应的数据模型表为shopping_cart:

对应的实体类ShoppingCart.java

package com.itheima.reggie.entity;

import lombok.Data;
import java.io.Serializable;
import java.math.BigDecimal;
import java.time.LocalDateTime;


@Data
public class ShoppingCart implements Serializable {

    private static final long serialVersionUID = 1L;

    private Long id;

    //名称
    private String name;

    //用户id
    private Long userId;

    //菜品id
    private Long dishId;

    //套餐id
    private Long setmealId;

    //口味
    private String dishFlavor;

    //数量
    private Integer number;

    //金额
    private BigDecimal amount;

    //图片
    private String image;

    private LocalDateTime createTime;
}

请求交互流程：

点击加入购物车或者按钮，页面发送ajax请求，请求服务端，将菜品或者套餐添加到购物车
点击购物车图标，页面发送aiax请求，请求服务端查询购物车中的菜品和套餐
点击清空购物车按钮，页面发送ajax请求，请求服务端来执行清空购物车操作

添加，清空购物车

用户登录之后根据用户ID对其购物车进行管理，可以添加与删除，查询购物车。

package com.itheima.reggie.controller;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import com.itheima.reggie.entity.ShoppingCart;
import com.itheima.reggie.service.ShoppingCartService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import java.util.List;


@RestController
@RequestMapping("/shoppingCart")
@Slf4j
public class ShoppingCartController {

    @Resource
    private ShoppingCartService shoppingCartService;

    
    @PostMapping("/add")
    public R add(@RequestBody ShoppingCart shoppingCart) {
        // 设置用户ID，指定当前是哪个用户的购物车数据
        Long currentId = BaseContext.getCurrentId();
        shoppingCart.setUserId(currentId);
        // 构造查询条件
        LambdaQueryWrapper queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(ShoppingCart::getUserId,currentId);
        // 查询当前菜品或者套餐是否在购物车里
        Long dishId = shoppingCart.getDishId();
        // 根据菜品ID是否为NULL
        if(dishId!=null){
            // 添加菜品
            queryWrapper.eq(ShoppingCart::getDishId,dishId);
        }else {
            // 添加套餐
            queryWrapper.eq(ShoppingCart::getSetmealId,shoppingCart.getSetmealId());
        }
        ShoppingCart shoppingCartOne = shoppingCartService.getOne(queryWrapper);
        if (shoppingCartOne!=null){
            // 如果存在就在原来基础上加上1
            Integer number = shoppingCartOne.getNumber();
            shoppingCartOne.setNumber(number+1);
            shoppingCartService.updateById(shoppingCartOne);
        }else {
            // 如果不存在则添加至购物车默认为1
            shoppingCart.setNumber(1);
            shoppingCartService.save(shoppingCart);
            shoppingCartOne = shoppingCart;
        }
        return R.success(shoppingCartOne);
    }

    
    @GetMapping("/list")
    public R> list(){
        // 构建查询条件 根据用户ID查询
        LambdaQueryWrapper queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(ShoppingCart::getUserId,BaseContext.getCurrentId());
        queryWrapper.orderByAsc(ShoppingCart::getCreateTime);
        List list = shoppingCartService.list(queryWrapper);
        return R.success(list);
    }

    
    @DeleteMapping("/clean")
    public R clean(){

        LambdaQueryWrapper queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(ShoppingCart::getUserId,BaseContext.getCurrentId());
        shoppingCartService.remove(queryWrapper);
        return R.success("清空购物车成功");

    }
}

二. 用户下单 2.1 需求分析

用户点完餐之后，点击去结算按钮进行下单。

涉及两张表：订单表与订单明细表

订单表：

订单明细表：

用户下单流程交互：

购物车中点击去结算，页面跳转至订单确认页面；
订单确认页发送ajax请求，获取当前用户默认地址；
获取当前购物车数据；
请求服务器完成下单操作。

订单表对应实体模型Orders.java

package com.itheima.reggie.entity;

import lombok.Data;
import java.io.Serializable;
import java.math.BigDecimal;
import java.time.LocalDateTime;


@Data
public class Orders implements Serializable {

    private static final long serialVersionUID = 1L;

    private Long id;

    //订单号
    private String number;

    //订单状态 1待付款，2待派送，3已派送，4已完成，5已取消
    private Integer status;
    
    //下单用户id
    private Long userId;

    //地址id
    private Long addressBookId;
    
    //下单时间
    private LocalDateTime orderTime;
    
    //结账时间
    private LocalDateTime checkoutTime;
    
    //支付方式 1微信，2支付宝
    private Integer payMethod;

    //实收金额
    private BigDecimal amount;

    //备注
    private String remark;

    //用户名
    private String userName;

    //手机号
    private String phone;

    //地址
    private String address;

    //收货人
    private String consignee;
}

订单表对应实体模型OrderDetail.java

package com.itheima.reggie.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import lombok.Data;
import java.io.Serializable;
import java.math.BigDecimal;


@Data
public class OrderDetail implements Serializable {

    private static final long serialVersionUID = 1L;

    private Long id;

    //名称
    private String name;

    //订单id
    private Long orderId;


    //菜品id
    private Long dishId;


    //套餐id
    private Long setmealId;


    //口味
    private String dishFlavor;


    //数量
    private Integer number;

    //金额
    private BigDecimal amount;

    //图片
    private String image;
}

用户下单操作需要根据用户的ID去查询出用户的购物车数据，然后默认选择的是用户的地址，下完单之后需要将用户的购物车数据进行清除：

package com.itheima.reggie.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.reggie.common.BaseContext;
import com.itheima.reggie.common.CustomException;
import com.itheima.reggie.entity.*;
import com.itheima.reggie.mapper.OrdersMapper;
import com.itheima.reggie.service.*;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
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 OrdersServiceImpl extends ServiceImpl implements OrdersService {

    @Resource
    private ShoppingCartService shoppingCartService;

    @Resource
    private UserService userService;

    @Resource
    private AddressBookService addressBookService;

    @Resource
    private OrderDetailService orderDetailService;

    
    @Override
    @Transactional
    public void submit(Orders orders) {
        // 获取当前用户
        Long currentId = BaseContext.getCurrentId();
        orders.setUserId(currentId);
        // 查询当前用户的购物车数据
        LambdaQueryWrapper queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(ShoppingCart::getUserId,currentId);
        List shoppingCarts = shoppingCartService.list(queryWrapper);
        // 判断购物车
        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(currentId);
        // 查询地址数据
        Long addressBookId = orders.getAddressBookId();
        AddressBook addressBook = addressBookService.getById(addressBookId);
        if(addressBook==null){
            throw new CustomException("地址为空，不能下单");
        }
        // 订单号
        long orderId = IdWorker.getId();
        // 计算购物车总金额 保证多线程情况下线程安全计算
        AtomicInteger amount = new AtomicInteger(0);
        List orderDetails = shoppingCarts.stream().map((item) -> {
            OrderDetail orderDetail = new OrderDetail();
            orderDetail.setOrderId(orderId);
            orderDetail.setNumber(item.getNumber());
            orderDetail.setDishFlavor(item.getDishFlavor());
            orderDetail.setDishId(item.getDishId());
            orderDetail.setSetmealId(item.getSetmealId());
            orderDetail.setName(item.getName());
            orderDetail.setImage(item.getImage());
            orderDetail.setAmount(item.getAmount());
            amount.addAndGet(item.getAmount().multiply(new BigDecimal(item.getNumber())).intValue());
            return orderDetail;
        }).collect(Collectors.toList());

        // 设置订单信息
        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(currentId);
        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()));
        //向订单表插入数据，一条数据
        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);


    }
}

瑞吉外卖项目：移动端购物车功能与用户下单功能开发

Java相关栏目本月热门文章