day08-优惠券秒杀04 - ToB企服应用市场:ToB评测及商务社交产业平台

package com.hmdp.service;
import com.baomidou.mybatisplus.extension.service.IService;
import com.hmdp.dto.Result;
import com.hmdp.entity.Voucher;
/**
* 服务类
*
* @author 李
* @version 1.0
*/
public interface IVoucherService extends IService<Voucher> {
void addSeckillVoucher(Voucher voucher);
}

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package com.hmdp.service.impl;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.entity.Voucher;
import com.hmdp.mapper.VoucherMapper;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherService;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import javax.annotation.Resource;
import static com.hmdp.utils.RedisConstants.SECKILL_STOCK_KEY;
/**
* 服务实现类
*
* @author 李
* @version 1.0
*/
@Service
public class VoucherServiceImpl extends ServiceImpl<VoucherMapper, Voucher> implements IVoucherService {
@Resource
private ISeckillVoucherService seckillVoucherService;
@Resource
private StringRedisTemplate stringRedisTemplate;
@Override
@Transactional
public void addSeckillVoucher(Voucher voucher) {
// 保存优惠券到数据库
save(voucher);
// 保存秒杀优惠券信息到数据库
SeckillVoucher seckillVoucher = new SeckillVoucher();
seckillVoucher.setVoucherId(voucher.getId());
seckillVoucher.setStock(voucher.getStock());
seckillVoucher.setBeginTime(voucher.getBeginTime());
seckillVoucher.setEndTime(voucher.getEndTime());
seckillVoucherService.save(seckillVoucher);
//保存秒杀库存到Redis中
stringRedisTemplate.opsForValue().set(SECKILL_STOCK_KEY + voucher.getId(), voucher.getStock().toString());
}
}

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package com.hmdp.controller;
import com.hmdp.dto.Result;
import com.hmdp.entity.Voucher;
import com.hmdp.service.IVoucherService;
import org.springframework.web.bind.annotation.*;
import javax.annotation.Resource;
/**
* 前端控制器
*
* @author 李
* @version 1.0
*/
@RestController
@RequestMapping("/voucher")
public class VoucherController {
@Resource
private IVoucherService voucherService;
/**
* 新增秒杀券
* @param voucher 优惠券信息，包含秒杀信息
* @return 优惠券id
*/
@PostMapping("seckill")
public Result addSeckillVoucher(@RequestBody Voucher voucher) {
voucherService.addSeckillVoucher(voucher);
return Result.ok(voucher.getId());
}
}

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-- 1.参数列表
-- 1.1 优惠券id
local voucherId = ARGV[1]
-- 1.2 用户id
local userId = ARGV[2]
-- 2.数据key
-- 2.1 库存key
local stockKey = 'seckill:stock:' .. voucherId
-- 2.2 订单key
local orderKey = 'seckill:order' .. voucherId
-- 3.脚本业务
-- 3.1判断库存是否充足 get stockKey
if (tonumber(redis.call('get', stockKey)) <= 0) then
-- 3.2库存不足,返回1
return 1
end
-- 3.3库存充足，判断用户是否下过单(判断用户id是否在订单key对应的集合中)
-- sismember orderKey userId
if (redis.call('sismember', orderKey, userId) == 1) then
-- 3.4 若存在，说明是重复下单，返回2
return 2
end
-- 3.5 扣库存 incrby stockKey -1
redis.call('incrby', stockKey, -1)
-- 3.6 下单（保存用户） sadd orderKey userId
redis.call('sadd', orderKey, userId)
return 0

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package com.hmdp.service.impl;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.Collections;
import java.util.concurrent.*;
/**
* 服务实现类
*
* @author 李
* @version 1.0
*/
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
@Resource
private ISeckillVoucherService seckillVoucherService;
@Resource
private RedisIdWorker redisIdWorker;
@Resource
private StringRedisTemplate stringRedisTemplate;
@Resource
private RedissonClient redissonClient;
private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
//类一加载就初始化脚本
static {
SECKILL_SCRIPT = new DefaultRedisScript<>();
SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
SECKILL_SCRIPT.setResultType(Long.class);
}
//阻塞队列：当一个线程尝试从队列中获取元素时，如果队列中没有元素，那么该线程就会被阻塞，直到队列中有元素，线程才会被唤醒并获取元素
private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
//线程池
private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();
//在当前类初始化完毕之后就执行
@PostConstruct
private void init() {
SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
}
//执行异步操作，从阻塞队列中获取订单
private class VoucherOrderHandler implements Runnable {
@Override
public void run() {
while (true) {
try {
//1.获取队列中的订单信息
/* take()--获取和删除阻塞对列中的头部，如果需要则等待直到元素可用
(因此不必担心这里的死循环会增加cpu的负担) */
VoucherOrder voucherOrder = orderTasks.take();
//2.创建订单
handleVoucherOrder(voucherOrder);
} catch (Exception e) {
log.error("处理订单异常", e);
}
}
}
}
private IVoucherOrderService proxy;
private void handleVoucherOrder(VoucherOrder voucherOrder) {
//获取用户（因为目前的是线程池对象，不是主线程，不能使用UserHolder从ThreadLocal中获取用户id）
Long userId = voucherOrder.getUserId();
//创建锁对象，指定锁的名称
RLock lock = redissonClient.getLock("lock:order:" + userId);
//获取锁（可重入锁）
boolean isLock = lock.tryLock();
//判断是否获取锁成功
if (!isLock) {
//获取锁失败
log.error("不允许重复下单");
}
try {
proxy.createVoucherOrder(voucherOrder);
} finally {
//释放锁
lock.unlock();
}
}
@Override
public Result seckillVoucher(Long voucherId) {
//获取用户id
Long userId = UserHolder.getUser().getId();
//1.执行lua脚本
Long result = stringRedisTemplate.execute(
SECKILL_SCRIPT,
Collections.emptyList(),
voucherId.toString(),
userId.toString()
);
//2.判断脚本执行结果是否为0
int r = result.intValue();
if (r != 0) {
//2.1如果不为0，代表没有购买资格
return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
}
//2.2如果为0，代表有购买资格，将下单信息保存到阻塞对列中
VoucherOrder voucherOrder = new VoucherOrder();
//设置订单id
long orderId = redisIdWorker.nextId("order");
voucherOrder.setId(orderId);
//设置用户id
voucherOrder.setUserId(userId);
//设置秒杀券id
voucherOrder.setVoucherId(voucherId);
//将上述信息保存到阻塞队列
orderTasks.add(voucherOrder);
//3.获取代理对象
proxy = (IVoucherOrderService) AopContext.currentProxy();
//4.返回订单id
return Result.ok(0);
}
@Transactional
public void createVoucherOrder(VoucherOrder voucherOrder) {
//一人一单
Long userId = voucherOrder.getUserId();
//查询订单
int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
if (count > 0) {//说明已经该用户已经对该优惠券下过单了
log.error("用户已经购买过一次!");
return;
}
//库存充足，则扣减库存（操作秒杀券表）
boolean success = seckillVoucherService.update()
.setSql("stock = stock -1")//set stock = stock -1
//where voucher_id =? and stock>0
.gt("stock", 0).eq("voucher_id", voucherOrder.getVoucherId()).update();
if (!success) {//操作失败
log.error("秒杀券库存不足!");
return;
}
//将订单写入数据库（操作优惠券订单表）
save(voucherOrder);
}
}

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