springboot秒杀课程学习整理1-5

2022-09-10 08:16:22

1)交易模型设计

交易模型(用户下单的交易模型)OrderModel

id(String 交易单号使用String)， userId，itemId，amount(数量)，orderAmount(总金额)， itemPrice(购买时的价格)

创建表order_info

id,userId,item_id,item_price,amount,order_amount

2）使用mybatis-generator生成对应的文件

3）生成订单的流程

1）校验商品是否存在，用户是否合法，购买数量是否正确

2）落单减库存（需要在ItemServiceImpl里添加方法用户更新库存数量，这里需要添加sql语句更新库存）

3) 生成订单（订单有一定的规则:这里是16位，由时间，自增序列，分库分表组成）

4）订单入库

5）添加销量（需要在itemServiceImpl里添加方法更新销量，并且需要新增sql语句）

OrderModel

package com.miaoshaproject.service.model;

import java.math.BigDecimal;

public class OrderModel {

    private String id;

    private Integer userId;

    private Integer itemId;

    private Integer amount;

    private BigDecimal orderAmount;

    private BigDecimal itemPrice;

    public String getId() {

        return id;

    }

    public void setId(String id) {

        this.id = id;

    }

    public Integer getUserId() {

        return userId;

    }

    public void setUserId(Integer userId) {

        this.userId = userId;

    }

    public Integer getItemId() {

        return itemId;

    }

    public void setItemId(Integer itemId) {

        this.itemId = itemId;

    }

    public Integer getAmount() {

        return amount;

    }

    public void setAmount(Integer amount) {

        this.amount = amount;

    }

    public BigDecimal getOrderAmount() {

        return orderAmount;

    }

    public void setOrderAmount(BigDecimal orderAmount) {

        this.orderAmount = orderAmount;

    }

    public BigDecimal getItemPrice() {

        return itemPrice;

    }

    public void setItemPrice(BigDecimal itemPrice) {

        this.itemPrice = itemPrice;

    }

}

OrderService

package com.miaoshaproject.service;

import com.miaoshaproject.error.BusinessException;

import com.miaoshaproject.service.model.OrderModel;

public interface OrderService {

    OrderModel createModel(Integer userId, Integer itemId, Integer amount) throws BusinessException;

}

OrderServiceIpml

package com.miaoshaproject.service.impl;

import com.miaoshaproject.dao.ItemDOMapper;

import com.miaoshaproject.dao.OrderDOMapper;

import com.miaoshaproject.dao.SequenceDOMapper;

import com.miaoshaproject.dao.UserDOMapper;

import com.miaoshaproject.dataobject.ItemDO;

import com.miaoshaproject.dataobject.OrderDO;

import com.miaoshaproject.dataobject.SequenceDO;

import com.miaoshaproject.dataobject.UserDO;

import com.miaoshaproject.error.BusinessException;

import com.miaoshaproject.error.EmBusinessError;

import com.miaoshaproject.service.OrderService;

import com.miaoshaproject.service.model.ItemModel;

import com.miaoshaproject.service.model.OrderModel;

import com.miaoshaproject.service.model.UserModel;

import org.springframework.beans.BeanUtils;

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

import org.springframework.stereotype.Service;

import org.springframework.transaction.annotation.Propagation;

import org.springframework.transaction.annotation.Transactional;

import java.math.BigDecimal;

import java.time.LocalDateTime;

import java.time.format.DateTimeFormatter;

import java.util.Date;

@Service

public class OrderServiceImpl implements OrderService {

    @Autowired

    private ItemServiceImpl itemService;

    @Autowired

    private UserServiceImpl userService;

    @Autowired

    private ItemDOMapper itemDOMapper;

    @Autowired

    private UserDOMapper userDOMapper;

    @Autowired

    private OrderDOMapper orderDOMapper;

    @Autowired

    private SequenceDOMapper sequenceDOMapper;

    @Override

    @Transactional //保证订单是在同一事务当中？

    public OrderModel createModel(Integer userId, Integer itemId, Integer amount) throws BusinessException {

       //1校验下单状态，下单的商品是否存在，用户是否合法，购买数量是否正确

       ItemModel itemModel = itemService.getItemById(itemId);

       if(itemModel == null){

           throw new BusinessException(EmBusinessError.PARAMTER_VALIDATION_ERROR,"商品信息不存在");

       }

       UserModel userModel =userService.getUserById(userId);

       if(userModel == null){

           throw new BusinessException(EmBusinessError.PARAMTER_VALIDATION_ERROR,"用户不存在");

       }

       if(amount<=0 || amount>99){

           throw new BusinessException(EmBusinessError.PARAMTER_VALIDATION_ERROR,"商品数量不正确");

       }

       //2.落单减库存

       boolean result =itemService.decreaseStock(itemId,amount);

       if(!result){

           throw new BusinessException(EmBusinessError.STOCK_NOT_ENOUGH);

       }

       //3.订单入库

       OrderModel orderModel = new OrderModel();

       orderModel.setUserId(userId);

       orderModel.setItemId(itemId);

       orderModel.setAmount(amount);

       orderModel.setItemPrice(itemModel.getPrice());

       orderModel.setOrderAmount(itemModel.getPrice().multiply(new BigDecimal(amount)));

       //生成订单号

       orderModel.setId(generatorOrderNo());

       OrderDO orderDO=this.convertOrderDOFromOrderModel(orderModel);

       orderDOMapper.insertSelective(orderDO);

       //加上销售额

        itemService.increaseSales(itemId,amount);

        //返回前端

        return orderModel;

    }

    public OrderDO convertOrderDOFromOrderModel(OrderModel orderModel){

        OrderDO orderDO = new OrderDO();

        if(orderModel == null){

            return null;

        }

        BeanUtils.copyProperties(orderModel,orderDO);

        orderDO.setItemPrice(orderModel.getItemPrice().doubleValue());

        orderDO.setOrderAmount(orderModel.getOrderAmount().doubleValue());

        return orderDO;

    }

    @Transactional(propagation = Propagation.REQUIRES_NEW)

    public String generatorOrderNo(){

        //订单号有16

        StringBuilder stringBuilder = new StringBuilder();

        // 前8位是时间年月日

        LocalDateTime now = LocalDateTime.now();

        String nowDate = now.format(DateTimeFormatter.ISO_DATE).replace("-","");

        stringBuilder.append(nowDate);

        //中间6位是自增序列,

        // 创建sequence_info表有字段name current_value step

        //每次加step，然后更新表，不够6位用0补上

        int sequence = 0;

        SequenceDO sequenceDO = sequenceDOMapper.getSequenceByName("order_info");

        sequence = sequenceDO.getCurrentValue();

        sequenceDO.setCurrentValue(sequenceDO.getCurrentValue()+sequenceDO.getStep());

        sequenceDOMapper.updateByPrimaryKey(sequenceDO);

        String sequenceStr = String.valueOf(sequence);

        for(int i=0;i<6 - sequenceStr.length(); i++){

            //这里需要考虑的一点是如果大于6的

            // 时候怎么处理

            stringBuilder.append(0);

        }

        stringBuilder.append(sequenceStr);

        //最后两位是分库分表位,这里而写死

        stringBuilder.append("00");

       return stringBuilder.toString();

    }

}

OrderController

package com.miaoshaproject.controller;

import com.miaoshaproject.error.BusinessException;

import com.miaoshaproject.error.EmBusinessError;

import com.miaoshaproject.response.CommonReturnType;

import com.miaoshaproject.service.impl.OrderServiceImpl;

import com.miaoshaproject.service.model.OrderModel;

import com.miaoshaproject.service.model.UserModel;

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

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletRequest;

@RestController

@RequestMapping("/order")

@CrossOrigin(allowCredentials = "true",allowedHeaders = "*")

public class OrderController extends BaseController{

    @Autowired

    private HttpServletRequest httpServletRequest;

    @Autowired

    private OrderServiceImpl orderService;

    @RequestMapping(value="create",method = RequestMethod.POST,consumes = {CONTENT_TYPE_FORMED})

    public CommonReturnType createOrder (@RequestParam(name="itemId")Integer itemId,

                                         @RequestParam(name="amount")Integer amount

    ) throws BusinessException {

        Boolean isLogin = (Boolean)httpServletRequest.getSession().getAttribute("IS_LOGIN");

        if(isLogin == null||!isLogin.booleanValue()){

            throw new BusinessException(EmBusinessError.USER_NOT_LOGIN,"用户还未登入不能下单");

        }

        UserModel userModel=(UserModel) httpServletRequest.getSession().getAttribute("LOGIN_USER");

        //进行下单操作

        OrderModel orderModel=orderService.createModel(userModel.getId(),itemId,amount);

        return CommonReturnType.create(null);

    }

}

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