SSM实现秒杀系统案例

2017-01-13 15:00:31来源:csdn作者:sdksdk0人点击

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[版权申明:本文系作者原创,转载请注明出处]
文章出处:http://blog.csdn.net/sdksdk0/article/details/52997034
作者:朱培 ID:sdksdk0

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好久没写博客了,因为一直在忙项目和其他工作中的事情,最近有空,刚好看到了一个秒杀系统的设计,感觉还是非常不错的一个系统,于是在这里分享一下。

秒杀场景主要两个点:
1:流控系统,防止后端过载或不必要流量进入,因为慕课要求课程的长度和简单性,没有加。
2:减库存竞争,减库存的update必然涉及exclusive lock ,持有锁的时间越短,并发性越高。

对于抢购系统来说,首先要有可抢购的活动,而且这些活动具有促销性质,比如直降500元。其次要求可抢购的活动类目丰富,用户才有充分的选择性。马上就双十一了,用户剁手期间增量促销活动量非常多,可能某个活动力度特别大,大多用户都在抢,必然对系统是一个考验。这样抢购系统具有秒杀特性,并发访问量高,同时用户也可选购多个限时抢商品,与普通商品一起进购物车结算。这种大型活动的负载可能是平时的几十倍,所以通过增加硬件、优化瓶颈代码等手段是很难达到目标的,所以抢购系统得专门设计。

在这里以秒杀单个功能点为例,以ssm框架+mysql+redis等技术来说明。

一、数据库设计

使用mysql数据库:这里主要是两个表,主要是一个商品表和一个购买明细表,在这里用户的购买信息的登录注册这里就不做了,用户购买时需要使用手机号码来进行秒杀操作,购买成功使用的是商品表id和购买明细的用户手机号码做为双主键。

CREATEDATABASE seckill;
USE seckill;CREATE TABLE seckill(
seckill_idBIGINT NOT NULL AUTO_INCREMENT COMMENT '商品库存id',
`name`VARCHAR(120)NOT NULL COMMENT '商品名称',
number INT NOT NULL COMMENT '库存数量',
start_time TIMESTAMP NOT NULL COMMENT '秒杀开启时间',
end_time TIMESTAMP NOT NULL COMMENT '秒杀结束时间',
create_time TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
PRIMARY KEY (seckill_id),
KEY idx_start_time(start_time),
KEY idx_end_time(end_time),
KEY idx_create_time(create_time))ENGINE=INNODB AUTO_INCREMENT=1000 DEFAULT CHARSET=utf8 COMMENT '秒杀库存表'
--初始化数据
INSERT INTO seckill(NAME,number,start_time,end_time)
VALUES
('4000元秒杀ipone7',300,'2016-11-5 00:00:00','2016-11-6 00:00:00'),
('3000元秒杀ipone6',200,'2016-11-5 00:00:00','2016-11-6 00:00:00'),
('2000元秒杀ipone5',100,'2016-11-5 00:00:00','2016-11-6 00:00:00'),
('1000元秒杀小米5',100,'2016-11-5 00:00:00','2016-11-6 00:00:00');--秒杀成功明细表
--用户登录认证相关的信息
CREATE TABLE success_kill(
seckill_idBIGINT NOT NULL AUTO_INCREMENT COMMENT '秒杀商品id',
user_phoneBIGINT NOT NULL COMMENT '用户手机号',
stateTINYINT NOT NULL DEFAULT-1 COMMENT '状态标识,-1无效,0成功,1已付款',
create_time TIMESTAMP NOT NULL COMMENT '创建时间',
PRIMARY KEY(seckill_id,user_phone),
KEY idx_create_time(create_time)
)ENGINE=INNODB AUTO_INCREMENT=1000 DEFAULT CHARSET=utf8 COMMENT '秒杀成功明细表'SELECT * FROM seckill;
SELECT * FROM success_kill;
这里我们还用到了一个存储过程,所以我们新建一个存储过程来处理,对于近日产品公司来说存储过程的使用还是比较多的,所以存储过程也还是要会写的。DELIMITER $$CREATE PROCEDURE seckill.execute_seckill
(IN v_seckill_id BIGINT, IN v_phone BIGINT,
IN v_kill_time TIMESTAMP, OUT r_result INT)
BEGIN
DECLARE insert_count INT DEFAULT 0;
START TRANSACTION;
INSERT IGNORE INTO success_kill(seckill_id,user_phone,create_time,state)
VALUE(v_seckill_id,v_phone,v_kill_time,0);
SELECT ROW_COUNT() INTO insert_count;
IF(insert_count = 0) THEN
ROLLBACK;
SET r_result = -1;
ELSEIF(insert_count < 0) THEN
ROLLBACK;
SET r_result = -2;
ELSE
UPDATE seckill
SET number = number - 1
WHERE seckill_id = v_seckill_id
AND end_time > v_kill_time
AND start_time < v_kill_time
AND number > 0;
SELECT ROW_COUNT() INTO insert_count;
IF(insert_count = 0) THEN
ROLLBACK;
SET r_result = 0;
ELSEIF (insert_count < 0) THEN
ROLLBACK;
SET r_result = -2;
ELSE
COMMIT;
SET r_result = 1;
END IF;
END IF;
END;
$$DELIMITER ;SET @r_result = -3;
CALL execute_seckill(1000,13813813822,NOW(),@r_result);
SELECT @r_result;
先可以看一下页面的展示情况:


二、实体类

因为我们有两个表,所以自然建两个实体bean啦!新建一个Seckill.java

private long seckillId;
private String name;
private int number;
private Date startTime;
private Date endTime;
private Date createTime;
实现其getter/setter方法。

再新建一个SuccessKill。

private long seckillId;
private long userPhone;
private short state;
private Date createTime;private Seckill seckill;
实现其getter/setter方法。
三、DAO接口层

接口我们也是来两个:SeckillDao.java和SuccessKillDao.java

内容分别为:

public interface SeckillDao {//减库存
int reduceNumber(@Param("seckillId")long seckillId,@Param("killTime")Date killTime);Seckill queryById(long seckilled);List<Seckill>queryAll(@Param("offset") int offset,@Param("limit") int limit);
public void seckillByProcedure(Map<String, Object> paramMap);
}
public interface SuccessKillDao {/**
* 插入购买明细
*
* @param seckillId
* @param userPhone
* @return
*/
int insertSuccessKill(@Param("seckillId")long seckillId,@Param("userPhone")long userPhone);/**
* 根据id查询
*
* @param seckill
* @return
*/
SuccessKillqueryByIdWithSeckill(@Param("seckillId")long seckillId,@Param("userPhone")long userPhone);
}

四、mapper处理

在mybatis中对上面的接口进行实现,这里可以通过mybatis来实现。

<mappernamespace="cn.tf.seckill.dao.SeckillDao">
<update id="reduceNumber">
updateseckill set number=number-1where seckill_id=#{seckillId}
and start_time <![CDATA[<=]]>#{killTime}
and end_time>=#{killTime}
and number >0
</update><select id="queryById"resultType="Seckill"parameterType="long">
selectseckill_id,name,number,start_time,end_time,create_time
from seckill
where seckill_id =#{seckillId}
</select><select id="queryAll"resultType="Seckill">
selectseckill_id,name,number,start_time,end_time,create_time
from seckill
order by create_time desc
limit #{offset},#{limit}
</select><select id="seckillByProcedure" statementType="CALLABLE">
call execute_seckill(
#{seckillId,jdbcType=BIGINT,mode=IN},
#{phone,jdbcType=BIGINT,mode=IN},
#{killTime,jdbcType=TIMESTAMP,mode=IN},
#{result,jdbcType=INTEGER,mode=OUT}
)
</select></mapper>

<mapper namespace="cn.tf.seckill.dao.SuccessKillDao">
<insert id="insertSuccessKill">
insert ignore into success_kill(seckill_id,user_phone,state)
values (#{seckillId},#{userPhone},0)
</insert><select id="queryByIdWithSeckill"resultType="SuccessKill">
select
sk.seckill_id,
sk.user_phone,
sk.create_time,
sk.state,
s.seckill_id "seckill.seckill_id",
s.name "seckill.name",
s.number"seckill.number",
s.start_time"seckill.start_time",
s.end_time"seckill.end_time",
s.create_time"seckill.create_time"
from success_kill sk
inner join seckill s on sk.seckill_id=s.seckill_id
where sk.seckill_id=#{seckillId} and sk.user_phone=#{userPhone} </select>
</mapper>五、redis缓存处理

在这里我们说的库存不是真正意义上的库存,其实是该促销可以抢购的数量,真正的库存在基础库存服务。用户点击『提交订单』按钮后,在抢购系统中获取了资格后才去基础库存服务中扣减真正的库存;而抢购系统控制的就是资格/剩余数。传统方案利用数据库行锁,但是在促销高峰数据库压力过大导致服务不可用,目前采用redis集群(16分片)缓存促销信息,例如促销id、促销剩余数、抢次数等,抢的过程中按照促销id散列到对应分片,实时扣减剩余数。当剩余数为0或促销删除,价格恢复原价。

这里使用的是redis来进行处理。这里使用的是序列化工具RuntimeSchema。

在pom.xml中配置如下:

<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.7.2</version>
</dependency><dependency>
<groupId>com.dyuproject.protostuff</groupId>
<artifactId>protostuff-api</artifactId>
<version>1.0.8</version>
</dependency>
<dependency>
<groupId>com.dyuproject.protostuff</groupId>
<artifactId>protostuff-core</artifactId>
<version>1.0.8</version>
</dependency>
<dependency>
<groupId>com.dyuproject.protostuff</groupId>
<artifactId>protostuff-runtime</artifactId>
<version>1.0.8</version>
</dependency>

然后我们引入之后,直接在这个dao中进行处理即可,就是把数据从redis中读取出来以及把数据存到redis中,如果redis中有这个数据就直接读,如果没有就存进去。public class RedisDao {private Logger logger = LoggerFactory.getLogger(this.getClass());
private JedisPool jedisPool;
private int port;
private String ip;public RedisDao(String ip, int port) {
this.port = port;
this.ip = ip;
}//Serialize function
private RuntimeSchema<Seckill> schema = RuntimeSchema.createFrom(Seckill.class);public Seckill getSeckill(long seckillId) {
jedisPool = new JedisPool(ip, port);
//redis operate
try {
Jedis jedis = jedisPool.getResource();
try {
String key = "seckill:" + seckillId;
//由于redis内部没有实现序列化方法,而且jdk自带的implaments Serializable比较慢,会影响并发,因此需要使用第三方序列化方法.
byte[] bytes = jedis.get(key.getBytes());
if(null != bytes){
Seckill seckill = schema.newMessage();
ProtostuffIOUtil.mergeFrom(bytes,seckill,schema);
//reSerialize
return seckill;
}
} finally {
jedisPool.close();
}
} catch (Exception e) {
logger.error(e.getMessage(),e);
}return null;
}public String putSeckill(Seckill seckill) {
jedisPool = new JedisPool(ip, port);
//set Object(seckill) ->Serialize -> byte[]
try{
Jedis jedis = jedisPool.getResource();
try{
String key = "seckill:"+seckill.getSeckillId();
byte[] bytes = ProtostuffIOUtil.toByteArray(seckill, schema, LinkedBuffer.allocate(LinkedBuffer.DEFAULT_BUFFER_SIZE));
//time outcache
int timeout = 60*60;
String result = jedis.setex(key.getBytes(),timeout,bytes);
return result;
}finally {
jedisPool.close();
}
}catch (Exception e){
logger.error(e.getMessage(),e);
}
return null;
}
}

还需要在spring中进行配置:我这里的地址使用的是我服务器的地址。<bean id="redisDao" class="cn.tf.seckill.dao.cache.RedisDao">
<constructor-arg index="0" value="115.28.16.234"></constructor-arg>
<constructor-arg index="1" value="6379"></constructor-arg>
</bean>


六、service接口及其实现

接下来就是service的处理了。这里主要是由两个重要的业务接口。

1、暴露秒杀 和 执行秒杀 是两个不同业务,互不影响 2、暴露秒杀 的逻辑可能会有更多变化,现在是时间上达到要求才能暴露,说不定下次加个别的条件才能暴露,基于业务耦合度考虑,分开比较好。3、重新更改暴露秒杀接口业务时,不会去影响执行秒杀接口,对于测试都是有好处的。。。另外 不好的地方是前端需要调用两个接口才能执行秒杀。

//从使用者角度设计接口,方法定义粒度,参数,返回类型
public interface SeckillService {List<Seckill>getSeckillList();Seckill getById(long seckillId);
//输出秒杀开启接口地址
ExposerexportSeckillUrl(long seckillId);/**
* 执行描述操作
*
* @param seckillId
* @param userPhone
* @param md5
*/
SeckillExecution executeSeckill(long seckillId,long userPhone,String md5)throws SeckillCloseException,RepeatKillException,SeckillException;
/**
* 通过存储过程执行秒杀
* @param seckillId
* @param userPhone
* @param md5
*/
SeckillExecution executeSeckillByProcedure(long seckillId, long userPhone, String md5);
}


实现的过程就比较复杂了,这里加入了前面所说的存储过程还有redis缓存。这里做了一些异常的处理,以及数据字典的处理。

@Service
public class SeckillServiceImpl implements SeckillService{private Logger logger=LoggerFactory.getLogger(this.getClass());@Autowired
private SeckillDaoseckillDao;
@Autowired
private SuccessKillDao successKillDao;
@Autowired
private RedisDao redisDao;//加盐处理
private final String slat="xvzbnxsd^&&*)(*()kfmv4165323DGHSBJ";
public List<Seckill> getSeckillList() {
return seckillDao.queryAll(0, 4);
}public Seckill getById(long seckillId) {
return seckillDao.queryById(seckillId);
}
public Exposer exportSeckillUrl(long seckillId) {//优化点:缓存优化Seckill seckill = redisDao.getSeckill(seckillId);
if (seckill == null) {
//访问数据库
seckill = seckillDao.queryById(seckillId);
if (seckill == null) {
return new Exposer(false, seckillId);
} else {
//放入redis
redisDao.putSeckill(seckill);
}
}
Date startTime = seckill.getStartTime();
Date endTime = seckill.getEndTime();
//当前系统时间
Date nowTime = new Date();
if (nowTime.getTime() < startTime.getTime()
|| nowTime.getTime() > endTime.getTime()) {
return new Exposer(false, seckillId, nowTime.getTime(), startTime.getTime(), endTime.getTime());
}
//转换特定字符串的过程,不可逆
String md5 = getMD5(seckillId);
return new Exposer(true, md5, seckillId);
}
@Transactional
public SeckillExecution executeSeckill(long seckillId, long userPhone, String md5)
throws SeckillException, RepeatKillException, SeckillCloseException {
if (md5 == null || (!md5.equals(getMD5(seckillId)))) {
throw new SeckillException("Seckill data rewrite");
}
//执行秒杀逻辑:减库存,记录购买行为
Date nowTime = new Date();
try {//记录购买行为
int insertCount = successKillDao.insertSuccessKill(seckillId, userPhone);
if (insertCount <= 0) {
//重复秒杀
throw new RepeatKillException("Seckill repeated");
} else {
//减库存
int updateCount = seckillDao.reduceNumber(seckillId, nowTime);
if (updateCount <= 0) {
//没有更新到记录,秒杀结束
throw new SeckillCloseException("Seckill is closed");
} else {
//秒杀成功
SuccessKill successKilled = successKillDao.queryByIdWithSeckill(seckillId, userPhone);
return new SeckillExecution(seckillId, SeckillStatEnum.SUCCESS, successKilled);}
}
} catch (SeckillCloseException e1) {
throw e1;
} catch (RepeatKillException e2) {
throw e2;
} catch (Exception e) {
logger.error(e.getMessage());
//所有编译期异常转换为运行时异常
throw new SeckillException("Seckill inner error" + e.getMessage());
}}/**
* @param seckillId
* @param userPhone
* @param md5
* @return
* @throws SeckillException
* @throws RepeteKillException
* @throws SeckillCloseException
*/
public SeckillExecution executeSeckillByProcedure(long seckillId, long userPhone, String md5) {
if (md5 == null || (!md5.equals(getMD5(seckillId)))) {
throw new SeckillException("Seckill data rewrite");
}
Date killTime = new Date();
Map<String, Object> map = new HashMap<String, Object>();
map.put("seckillId", seckillId);
map.put("phone", userPhone);
map.put("killTime", killTime);
map.put("result", null);
//执行存储过程,result被赋值
try {
seckillDao.seckillByProcedure(map);
//获取result
int result = MapUtils.getInteger(map, "result", -2);
if (result == 1) {
SuccessKill successKilled = successKillDao.queryByIdWithSeckill(seckillId, userPhone);
return new SeckillExecution(seckillId, SeckillStatEnum.SUCCESS, successKilled);
} else {
return new SeckillExecution(seckillId, SeckillStatEnum.stateOf(result));
}
} catch (Exception e) {
logger.error(e.getMessage(), e);
return new SeckillExecution(seckillId, SeckillStatEnum.INNER_ERROR);
}
}private String getMD5(long seckillId) {
String base = seckillId + "/" + slat;
String md5 = DigestUtils.md5DigestAsHex(base.getBytes());
return md5;
}
}


七、Controller层处理

在springMVC中,是基于restful风格来对访问地址进行处理,所以我们在控制层也这样进行处理。

@Controller
@RequestMapping("/seckill")
public class SeckillController {private final Logger logger=LoggerFactory.getLogger(this.getClass());
@Autowired
private SeckillService seckillService;@RequestMapping(value="/list",method=RequestMethod.GET)
public String list(Model model){List<Seckill> list = seckillService.getSeckillList();
model.addAttribute("list",list);
return "list";
} @RequestMapping(value = "/{seckillId}/detail", method = RequestMethod.GET)
public String detail(@PathVariable("seckillId") Long seckillId, Model model){
if(seckillId == null){
return "redirect:/seckill/list";
}
Seckill seckill = seckillService.getById(seckillId);
if(seckill == null){
return "redirect:/seckill/list";
}
model.addAttribute("seckill", seckill);
return "detail";
}@RequestMapping(value = "/{seckillId}/exposer",
method = RequestMethod.POST,
produces = {"application/json;charset=UTF-8"})
@ResponseBody
public SeckillResult<Exposer> exposer(@PathVariable("seckillId") Long seckillId){
SeckillResult<Exposer> result;
try {
Exposer exposer = seckillService.exportSeckillUrl(seckillId);
result = new SeckillResult<Exposer>(true,exposer);
} catch (Exception e) {
result = new SeckillResult<Exposer>(false, e.getMessage());
}
return result;
}@RequestMapping(value = "/{seckillId}/{md5}/execution",
method = RequestMethod.POST,
produces = {"application/json;charset=UTF-8"})
@ResponseBody
public SeckillResult<SeckillExecution> execute(@PathVariable("seckillId")Long seckillId,
@PathVariable("md5")String md5,
@CookieValue(value = "killPhone", required = false)Long phone){
if(phone == null){
return new SeckillResult<>(false, "未注册");
}try {
SeckillExecution execution = seckillService.executeSeckillByProcedure(seckillId, phone, md5);
return new SeckillResult<SeckillExecution>(true, execution);
} catch (SeckillCloseException e) {
SeckillExecution execution = new SeckillExecution(seckillId, SeckillStatEnum.REPEAT_KILL);
return new SeckillResult<SeckillExecution>(false, execution);
} catch (RepeatKillException e) {
SeckillExecution execution = new SeckillExecution(seckillId, SeckillStatEnum.END);
return new SeckillResult<SeckillExecution>(false, execution);
} catch (Exception e) {
logger.error(e.getMessage(), e);
SeckillExecution execution = new SeckillExecution(seckillId, SeckillStatEnum.INNER_ERROR);
return new SeckillResult<SeckillExecution>(false, execution);
}
}@RequestMapping(value = "/time/now", method = RequestMethod.GET)
@ResponseBody
public SeckillResult<Long> time(){
Date now = new Date();
return new SeckillResult<>(true, now.getTime());
}
}

八、前台处理

后台数据处理完之后就是前台了,对于页面什么的就直接使用bootstrap来处理了,直接调用bootstrap的cdn链接地址。

页面的代码我就不贴出来了,可以到源码中进行查看,都是非常经典的几个页面。值得一提的是这个js的分模块处理。

//存放主要交互逻辑的js代码
// javascript 模块化(package.类.方法)var seckill = {//封装秒杀相关ajax的url
URL: {
now: function () {
return '/SecKill/seckill/time/now';
},
exposer: function (seckillId) {
return '/SecKill/seckill/' + seckillId + '/exposer';
},
execution: function (seckillId, md5) {
return '/SecKill/seckill/' + seckillId + '/' + md5 + '/execution';
}
},//验证手机号
validatePhone: function (phone) {
if (phone && phone.length == 11 && !isNaN(phone)) {
return true;//直接判断对象会看对象是否为空,空就是undefine就是false; isNaN 非数字返回true
} else {
return false;
}
},//详情页秒杀逻辑
detail: {
//详情页初始化
init: function (params) {
//手机验证和登录,计时交互
//规划我们的交互流程
//在cookie中查找手机号
var killPhone = $.cookie('killPhone');
//验证手机号
if (!seckill.validatePhone(killPhone)) {
//绑定手机 控制输出
var killPhoneModal = $('#killPhoneModal');
killPhoneModal.modal({
show: true,//显示弹出层
backdrop: 'static',//禁止位置关闭
keyboard: false//关闭键盘事件
});$('#killPhoneBtn').click(function () {
var inputPhone = $('#killPhoneKey').val();
console.log("inputPhone: " + inputPhone);
if (seckill.validatePhone(inputPhone)) {
//电话写入cookie(7天过期)
$.cookie('killPhone', inputPhone, {expires: 7, path: '/SecKill'});
//验证通过  刷新页面
window.location.reload();
} else {
//todo 错误文案信息抽取到前端字典里
$('#killPhoneMessage').hide().html('<label class="label label-danger">手机号错误!</label>').show(300);
}
});
}//已经登录
//计时交互
var startTime = params['startTime'];
var endTime = params['endTime'];
var seckillId = params['seckillId'];
$.get(seckill.URL.now(), {}, function (result) {
if (result && result['success']) {
var nowTime = result['data'];//解决计时误差
var userNowTime = new Date().getTime();
console.log('nowTime:' + nowTime);
console.log('userNowTime:' + userNowTime);//计算用户时间和系统时间的差,忽略中间网络传输的时间(本机测试大约为50-150毫秒)
var deviationTime = userNowTime - nowTime;
console.log('deviationTime:' + deviationTime);
//考虑到用户时间可能和服务器时间不一致,开始秒杀时间需要加上时间差
startTime = startTime + deviationTime;
//
//时间判断 计时交互
seckill.countDown(seckillId, nowTime, startTime, endTime);
} else {
console.log('result: ' + result);
alert('result: ' + result);
}
});
}
},handlerSeckill: function (seckillId, node) {
//获取秒杀地址,控制显示器,执行秒杀
node.hide().html('<button class="btn btn-primary btn-lg" id="killBtn">开始秒杀</button>');$.post(seckill.URL.exposer(seckillId), {}, function (result) {
//在回调函数种执行交互流程
if (result && result['success']) {
var exposer = result['data'];
if (exposer['exposed']) {
//开启秒杀
//获取秒杀地址
var md5 = exposer['md5'];
var killUrl = seckill.URL.execution(seckillId, md5);
console.log("killUrl: " + killUrl);
//绑定一次点击事件
$('#killBtn').one('click', function () {
//执行秒杀请求
//1.先禁用按钮
$(this).addClass('disabled');//,<-$(this)===('#killBtn')->
//2.发送秒杀请求执行秒杀
$.post(killUrl, {}, function (result) {
if (result && result['success']) {
var killResult = result['data'];
var state = killResult['state'];
var stateInfo = killResult['stateInfo'];
//显示秒杀结果
node.html('<span class="label label-success">' + stateInfo + '</span>');
}
});
});
node.show();
} else {
//未开启秒杀(由于浏览器计时偏差,以为时间到了,结果时间并没到,需要重新计时)
var now = exposer['now'];
var start = exposer['start'];
var end = exposer['end'];
var userNowTime = new Date().getTime();
var deviationTime = userNowTime - nowTime;
start = start + deviationTime;
seckill.countDown(seckillId, now, start, end);
}
} else {
console.log('result: ' + result);
}
});},countDown: function (seckillId, nowTime, startTime, endTime) {
console.log(seckillId + '_' + nowTime + '_' + startTime + '_' + endTime);
var seckillBox = $('#seckill-box');
if (nowTime > endTime) {
//秒杀结束
seckillBox.html('秒杀结束!');
} else if (nowTime < startTime) {
//秒杀未开始,计时事件绑定
var killTime = new Date(startTime);//todo 防止时间偏移
seckillBox.countdown(killTime, function (event) {
//时间格式
var format = event.strftime('秒杀倒计时: %D天 %H时 %M分 %S秒 ');
seckillBox.html(format);
}).on('finish.countdown', function () {
//时间完成后回调事件
//获取秒杀地址,控制现实逻辑,执行秒杀
console.log('______fininsh.countdown');
seckill.handlerSeckill(seckillId, seckillBox);
});
} else {
//秒杀开始
seckill.handlerSeckill(seckillId, seckillBox);
}
}}
用户秒杀之前需要先登记用户的手机号码,这个号码会保存在cookie中。

到了秒杀开始时间段,用户就可以点击按钮进行秒杀操作。


每个用户只能秒杀一次,不能重复秒杀,如果重复执行,会显示重复秒杀。


秒杀倒计时:


总结:其实在真实的秒杀系统中,我们是不直接对数据库进行操作的,我们一般是会放到redis中进行处理,企业的秒杀目前应该考虑使用redis,而不是mysql。其实高并发是个伪命题,根据业务场景,数据规模,架构的变化而变化。开发高并发相关系统的基础知识大概有:多线程,操作系统IO模型,分布式存储,负载均衡和熔断机制,消息服务,甚至还包括硬件知识。每块知识都需要一定的学习周期,需要几年的时间总结和提炼。

源码地址:https://github.com/sdksdk0/SecKill


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