说明： 这里涉及到VO层，先仔细看看VO层是怎样构成的。。。
这里重点只讲关于秒杀活动。。。商品详情这些源码也能看得八九不离十。
项目预览
活动还未开始，此刻还不能下单。。。
如果秒杀时间已过，也不会显示秒杀信息！
总结：这里使用Ajax是最好的选择，ajax最擅长于局部信息的刷新，不会刷新整个页面，给服务器造成压力。。。
秒杀活动
分析秒杀模型
由上图可知，数据库的存储样式是完全按照DO层进行一一对应存储的，我们在service层进行逻辑判断的时候，需要设计Mapper层即通过DO去向数据库查询数据，这里可能会涉及多张表的数据操作，所以我们干脆就把多张表里所需数据抽象出来重新建个DO层，便于后续Service进行逻辑处理，而这个抽象出来的DO层正是我们的Model，是由多个DO聚合而成，为何叫他是抽象呢？因为这个DO(我们的Model啦，比如ItemModel) 并没有像下面的PromoDO和ItemDO一样有对应的数据表进行一一对应，（相当与我们面向对象所学的小狗汪汪叫与小猫喵喵叫各自的特点抽离出形成一个动物类的叫声？），于是Model层之间也要互相影响，比如ItemModel里的商品id在PromoModel与秒杀商品id对应的话，表示此商品就是个秒杀商品，我们会在ItemModel的基础上与PromoModel的秒杀信息聚合在一起，组成ItemVO,其中包含了商品的秒杀价格(来自PromoModel)以及库存商品名等(来自ItemModel)。。。
商品详情Cotroller层
package com.imooc.miaoshaproject.controller;
import java.math.BigDecimal;
import java.util.List;
import java.util.stream.Collectors;
import com.imooc.miaoshaproject.controller.viewobject.ItemVO;
import com.imooc.miaoshaproject.error.BusinessException;
import com.imooc.miaoshaproject.response.CommonReturnType;
import com.imooc.miaoshaproject.service.model.ItemModel;
import org.joda.time.format.DateTimeFormat;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import com.imooc.miaoshaproject.service.ItemService;
/**
* Created by hzllb on 2018/11/18. */@Controller("/item")
@RequestMapping("/item")
@CrossOrigin(origins = {"*"},allowCredentials = "true")
public class ItemController extends BaseController {
@Autowired
private ItemService itemService;
//创建商品的controller
@RequestMapping(value = "/create",method = {RequestMethod.POST},consumes={CONTENT_TYPE_FORMED})
@ResponseBody
public CommonReturnType createItem(@RequestParam(name = "title")String title,
@RequestParam(name = "description")String description,
@RequestParam(name = "price")BigDecimal price,
@RequestParam(name = "stock")Integer stock,
@RequestParam(name = "imgUrl")String imgUrl) throws BusinessException {
//封装service请求用来创建商品
ItemModel itemModel = new ItemModel();
itemModel.setTitle(title);
itemModel.setDescription(description);
itemModel.setPrice(price);
itemModel.setStock(stock);
itemModel.setImgUrl(imgUrl);
ItemModel itemModelForReturn = itemService.createItem(itemModel);
ItemVO itemVO = convertVOFromModel(itemModelForReturn);
return CommonReturnType.create(itemVO);
}
//商品详情页浏览
@RequestMapping(value = "/get",method = {RequestMethod.GET})
@ResponseBody
public CommonReturnType getItem(@RequestParam(name = "id")Integer id){
ItemModel itemModel = itemService.getItemById(id);
ItemVO itemVO = convertVOFromModel(itemModel);
return CommonReturnType.create(itemVO);
}
//商品列表页面浏览
@RequestMapping(value = "/list",method = {RequestMethod.GET})
@ResponseBody
public CommonReturnType listItem(){
List<ItemModel> itemModelList = itemService.listItem();
//使用stream apiJ将list内的itemModel转化为ITEMVO;
List<ItemVO> itemVOList = itemModelList.stream().map(itemModel -> {
ItemVO itemVO = this.convertVOFromModel(itemModel);
return itemVO;
}).collect(Collectors.toList());
return CommonReturnType.create(itemVOList);
}
private ItemVO convertVOFromModel(ItemModel itemModel){
if(itemModel == null){
return null;
}
ItemVO itemVO = new ItemVO();
BeanUtils.copyProperties(itemModel,itemVO);
if(itemModel.getPromoModel() != null){
//有正在进行或即将进行的秒杀活动
itemVO.setPromoStatus(itemModel.getPromoModel().getStatus());
itemVO.setPromoId(itemModel.getPromoModel().getId());
itemVO.setStartDate(itemModel.getPromoModel().getStartDate().toString(DateTimeFormat.forPattern("yyyy-MM-dd HH:mm:ss")));
itemVO.setPromoPrice(itemModel.getPromoModel().getPromoItemPrice());
}else{
itemVO.setPromoStatus(0);
}
return itemVO;
}
}关于将Model层转为VO层呈现给用户，用到了Stream.map().collect()流式处理：
stream().map().collect()_-星雨-的博客-CSDN博客
下单后，生成订单
订单Controller层
package com.imooc.miaoshaproject.controller;
import com.imooc.miaoshaproject.service.OrderService;
import com.imooc.miaoshaproject.error.BusinessException;
import com.imooc.miaoshaproject.error.EmBusinessError;
import com.imooc.miaoshaproject.response.CommonReturnType;
import com.imooc.miaoshaproject.service.model.OrderModel;
import com.imooc.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;
/**
* Created by hzllb on 2018/11/18. */@Controller("order")
@RequestMapping("/order")
@CrossOrigin(origins = {"*"},allowCredentials = "true")
public class OrderController extends BaseController {
@Autowired
private OrderService orderService;
@Autowired
private HttpServletRequest httpServletRequest;
//封装下单请求
@RequestMapping(value = "/createorder",method = {RequestMethod.POST},consumes={CONTENT_TYPE_FORMED})
@ResponseBody
public CommonReturnType createOrder(@RequestParam(name="itemId")Integer itemId,
@RequestParam(name="amount")Integer amount,
@RequestParam(name="promoId",required = false)Integer promoId) throws BusinessException {
Boolean isLogin = (Boolean) httpServletRequest.getSession().getAttribute("IS_LOGIN");
if(isLogin == null || !isLogin.booleanValue()){
throw new BusinessException(EmBusinessError.USER_NOT_LOGIN,"用户还未登陆，不能下单");
}
//获取用户的登陆信息
UserModel userModel = (UserModel)httpServletRequest.getSession().getAttribute("LOGIN_USER");
OrderModel orderModel = orderService.createOrder(userModel.getId(),itemId,promoId,amount);
return CommonReturnType.create(null);
}
}说明：
订单创建Service层
package com.imooc.miaoshaproject.service.impl;
import com.imooc.miaoshaproject.dao.OrderDOMapper;
import com.imooc.miaoshaproject.dataobject.SequenceDO;
import com.imooc.miaoshaproject.error.BusinessException;
import com.imooc.miaoshaproject.error.EmBusinessError;
import com.imooc.miaoshaproject.service.ItemService;
import com.imooc.miaoshaproject.service.OrderService;
import com.imooc.miaoshaproject.service.UserService;
import com.imooc.miaoshaproject.service.model.ItemModel;
import com.imooc.miaoshaproject.service.model.OrderModel;
import com.imooc.miaoshaproject.service.model.UserModel;
import com.imooc.miaoshaproject.dao.SequenceDOMapper;
import com.imooc.miaoshaproject.dataobject.OrderDO;
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;
/**
* Created by hzllb on 2018/11/18. */@Service
public class OrderServiceImpl implements OrderService {
@Autowired
private SequenceDOMapper sequenceDOMapper;
@Autowired
private ItemService itemService;
@Autowired
private UserService userService;
@Autowired
private OrderDOMapper orderDOMapper;
@Override
@Transactional public OrderModel createOrder(Integer userId, Integer itemId, Integer promoId, 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.PARAMETER_VALIDATION_ERROR,"商品信息不存在");
}
UserModel userModel = userService.getUserById(userId);
if(userModel == null){
throw new BusinessException(EmBusinessError.PARAMETER_VALIDATION_ERROR,"用户信息不存在");
}
if(amount <= 0 || amount > 99){
throw new BusinessException(EmBusinessError.PARAMETER_VALIDATION_ERROR,"数量信息不正确");
}
//校验活动信息
if(promoId != null){
//（1）校验对应活动是否存在这个适用商品
if(promoId.intValue() != itemModel.getPromoModel().getId()){
throw new BusinessException(EmBusinessError.PARAMETER_VALIDATION_ERROR,"活动信息不正确");
//（2）校验活动是否正在进行中
}else if(itemModel.getPromoModel().getStatus().intValue() != 2) {
throw new BusinessException(EmBusinessError.PARAMETER_VALIDATION_ERROR,"活动信息还未开始");
}
}
//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);
if(promoId != null){
orderModel.setItemPrice(itemModel.getPromoModel().getPromoItemPrice());
}else{
orderModel.setItemPrice(itemModel.getPrice());
}
orderModel.setPromoId(promoId);
orderModel.setOrderPrice(orderModel.getItemPrice().multiply(new BigDecimal(amount)));
//生成交易流水号,订单号
orderModel.setId(generateOrderNo());
OrderDO orderDO = convertFromOrderModel(orderModel);
orderDOMapper.insertSelective(orderDO);
//加上商品的销量
itemService.increaseSales(itemId,amount);
//4.返回前端
return orderModel;
}
@Transactional(propagation = Propagation.REQUIRES_NEW)
private String generateOrderNo(){
//订单号有16位
StringBuilder stringBuilder = new StringBuilder();
//前8位为时间信息，年月日
LocalDateTime now = LocalDateTime.now();
String nowDate = now.format(DateTimeFormatter.ISO_DATE).replace("-","");
stringBuilder.append(nowDate);
//中间6位为自增序列
//获取当前sequence
int sequence = 0;
SequenceDO sequenceDO = sequenceDOMapper.getSequenceByName("order_info");
sequence = sequenceDO.getCurrentValue();
sequenceDO.setCurrentValue(sequenceDO.getCurrentValue() + sequenceDO.getStep());
sequenceDOMapper.updateByPrimaryKeySelective(sequenceDO);
String sequenceStr = String.valueOf(sequence);
for(int i = 0; i < 6-sequenceStr.length();i++){
stringBuilder.append(0);
}
stringBuilder.append(sequenceStr);
//最后2位为分库分表位,暂时写死
stringBuilder.append("00");
return stringBuilder.toString();
}
private OrderDO convertFromOrderModel(OrderModel orderModel){
if(orderModel == null){
return null;
}
OrderDO orderDO = new OrderDO();
BeanUtils.copyProperties(orderModel,orderDO);
orderDO.setItemPrice(orderModel.getItemPrice().doubleValue());
orderDO.setOrderPrice(orderModel.getOrderPrice().doubleValue());
return orderDO;
}
}这里重点讲一下订单流水号的生成：
看看数据库：
