这期内容当中小编将会给大家带来有关springboot+websocket怎样实现并发抢红包功能，文章内容丰富且以专业的角度为大家分析和叙述，阅读完这篇文章希望大家可以有所收获。
抢红包功能作为几大高并发场景中典型，应该如何实现？
参考微信抢红包功能，将抢红包分成一下几个步骤：
发红包；主要填写红包信息，生成红包记录
红包支付回调；用户发红包支付成功后，收到微信支付付款成功的回调，生成指定数量的红包。
抢红包；用户并发抢红包。
拆红包；记录用户抢红包记录，转账抢到的红包金额。
项目使用sessionId模拟用户，示例打开俩个浏览器窗口模拟两个用户。
红包记录在 redpacket 表中，用户领取红包详情记录在 redpacket_detail 表中。
CREATE DATABASE `redpacket`; use `redpacket`; CREATE TABLE `redpacket`.`redpacket` ( `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID', `packet_no` varchar(32) NOT NULL COMMENT '订单号', `amount` decimal(5,2) NOT NULL COMMENT '红包金额最高10000.00元', `num` int(11) NOT NULL COMMENT '红包数量', `order_status` int(4) NOT NULL DEFAULT '0' COMMENT '订单状态：0初始、1待支付、2支付成功、3取消', `pay_seq` varchar(32) DEFAULT NULL COMMENT '支付流水号', `create_time` datetime NOT NULL COMMENT '创建时间', `user_id` varchar(32) NOT NULL COMMENT '用户ID', `update_time` datetime NOT NULL COMMENT '更新时间', `pay_time` datetime DEFAULT NULL COMMENT '支付时间', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='红包订单表'; CREATE TABLE `redpacket`.`redpacket_detail` ( `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID', `packet_id` bigint(20) NOT NULL COMMENT '红包ID', `amount` decimal(5,2) NOT NULL COMMENT '红包金额', `received` int(1) NOT NULL DEFAULT '0' COMMENT '是否领取0未领取、1已领取', `create_time` datetime NOT NULL COMMENT '创建时间', `update_time` datetime NOT NULL COMMENT '更新时间', `user_id` varchar(32) DEFAULT NULL COMMENT '领取用户', `packet_no` varchar(32) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='红包详情表';
用户需要填写红包金额、红包数量、备注信息等，生成红包记录，微信收银台下单，返回用户支付。
public RedPacket generateRedPacket(ReqSendRedPacketsVO data,String userId) {
final BigDecimal amount = data.getAmount();
//红包数量
final Integer num = data.getNum();
//初始化订单
final RedPacket redPacket = new RedPacket();
redPacket.setPacketNo(UUID.randomUUID().toString().replace("-", ""));
redPacket.setAmount(amount);
redPacket.setNum(num);
redPacket.setUserId(userId);
Date now = new Date();
redPacket.setCreateTime(now);
redPacket.setUpdateTime(now);
int i = redPacketMapper.insertSelective(redPacket);
if (i != 1) {
throw new ServiceException("生成红包出错", ExceptionType.SYS_ERR);
}
//模拟收银台下单
String paySeq = UUID.randomUUID().toString().replace("-", "");
//拿到收银台下单结果，更新订单为待支付状态
redPacket.setOrderStatus(1);//待支付
redPacket.setPaySeq(paySeq);
i = redPacketMapper.updateByPrimaryKeySelective(redPacket);
if (i != 1) {
throw new ServiceException("生成红包出错", ExceptionType.SYS_ERR);
}
return redPacket;
}
用户支付成功后，系统接收到微信回调接口。
更新红包支付状态
二倍均值法生成指定数量红包，并批量入库。 红包算法参考：Java实现4种微信抢红包算法
红包总数入redis，设置红包过期时间24小时
websocket通知在线用户收到新的红包
@Transactional(rollbackFor = Exception.class)
public void dealAfterOrderPayCallback(String userId,ReqOrderPayCallbackVO data) {
RedPacketExample example = new RedPacketExample();
final String packetNo = data.getPacketNo();
final String paySeq = data.getPaySeq();
final Integer payStatus = data.getPayStatus();
example.createCriteria().andPacketNoEqualTo(packetNo)
.andPaySeqEqualTo(paySeq)
.andOrderStatusEqualTo(1);//待支付状态
//更新订单支付状态
Date now = new Date();
RedPacket updateRedPacket = new RedPacket();
updateRedPacket.setOrderStatus(payStatus);
updateRedPacket.setUpdateTime(now);
updateRedPacket.setPayTime(now);
int i = redPacketMapper.updateByExampleSelective(updateRedPacket, example);
if (i != 1) {
throw new ServiceException("订单状态更新失败", ExceptionType.SYS_ERR);
}
if (payStatus == 2) {
RedPacketExample query = new RedPacketExample();
query.createCriteria().andPacketNoEqualTo(packetNo)
.andPaySeqEqualTo(paySeq)
.andOrderStatusEqualTo(2);
final RedPacket redPacket = redPacketMapper.selectByExample(query).get(0);
final List<BigDecimal> detailList = getRedPacketDetail(redPacket.getAmount(), redPacket.getNum());
final int size = detailList.size();
if (size <= 100) {
i = detailMapper.batchInsert(detailList, redPacket);
if (size != i) {
throw new ServiceException("生成红包失败", ExceptionType.SYS_ERR);
}
} else {
int times = size % 100 == 0 ? size / 100 : (size / 100 + 1);
for (int j = 0; j < times; j++) {
int fromIndex = 100 * j;
int toIndex = 100 * (j + 1) - 1;
if (toIndex > size - 1) {
toIndex = size - 1;
}
final List<BigDecimal> subList = detailList.subList(fromIndex, toIndex);
i = detailMapper.batchInsert(subList, redPacket);
if (subList.size() != i) {
throw new ServiceException("生成红包失败", ExceptionType.SYS_ERR);
}
}
}
final String redisKey = REDPACKET_NUM_PREFIX + redPacket.getPacketNo();
String lua = "local i = redis.call('setnx',KEYS[1],ARGV[1])\r\n" +
"if i == 1 then \r\n" +
" local j = redis.call('expire',KEYS[1],ARGV[2])\r\n" +
"end \r\n" +
"return i";
//优化成lua脚本
final Long execute = redisTemplate.execute(new DefaultRedisScript<>(lua, Long.class), Arrays.asList(redisKey), size, 3600 * 24);
if (execute != 1L) {
throw new ServiceException("生成红包失败", ExceptionType.SYS_ERR);
}
//websocket通知在线用户收到新的红包
Websocket.sendMessageToUser(userId, JSONObject.toJSONString(redPacket));
}
}
/**
* 红包随机算法
*
* @param amount 红包金额
* @param num 红包数量
* @return 随机红包集合
*/
private List<BigDecimal> getRedPacketDetail(BigDecimal amount, Integer num) {
List<BigDecimal> redPacketsList = new ArrayList<>(num);
//最小红包金额
final BigDecimal min = new BigDecimal("0.01");
//最少需要红包金额
final BigDecimal bigNum = new BigDecimal(num);
final BigDecimal atLastAmount = min.multiply(bigNum);
//出去最少红包金额后剩余金额
BigDecimal remain = amount.subtract(atLastAmount);
if (remain.compareTo(BigDecimal.ZERO) == 0) {
for (int i = 0; i < num; i++) {
redPacketsList.add(min);
}
return redPacketsList;
}
final Random random = new Random();
final BigDecimal hundred = new BigDecimal("100");
final BigDecimal two = new BigDecimal("2");
BigDecimal redPacket;
for (int i = 0; i < num; i++) {
if (i == num - 1) {
redPacket = remain;
} else {
//100内随机获得的整数
final int rand = random.nextInt(100);
redPacket = new BigDecimal(rand).multiply(remain.multiply(two).divide(bigNum.subtract(new BigDecimal(i)), 2, RoundingMode.CEILING)).divide(hundred, 2, RoundingMode.FLOOR);
}
if (remain.compareTo(redPacket) > 0) {
remain = remain.subtract(redPacket);
} else {
remain = BigDecimal.ZERO;
}
redPacketsList.add(min.add(redPacket));
}
return redPacketsList;
}页面加载成功后初始化websocket,监听后端新红包生成成功，动态添加红包到聊天窗口。
$(function (){
var websocket;
if('WebSocket' in window) {
console.log("此浏览器支持websocket");
websocket = new WebSocket("ws://127.0.0.1:8082/websocket/${session.id}");
} else if('MozWebSocket' in window) {
alert("此浏览器只支持MozWebSocket");
} else {
alert("此浏览器只支持SockJS");
}
websocket.onopen = function(evnt) {
console.log("链接服务器成功!")
};
websocket.onmessage = function(evnt) {
console.log(evnt.data);
var json = eval('('+evnt.data+ ')');
obj.addPacket(json.id,json.packetNo,json.userId)
};
websocket.onerror = function(evnt) {};
websocket.onclose = function(evnt) {
console.log("与服务器断开了链接!")
}
});抢红包设计高并发，本地单机项目，通过原子Integer控制抢红包接口并发限制为20，
private AtomicInteger receiveCount = new AtomicInteger(0);
@PostMapping("/receive")
public CommonJsonResponse receiveOne(@Validated @RequestBody CommonJsonRequest<ReqReceiveRedPacketVO> vo) {
Integer num = null;
try {
//控制并发不要超过20
if (receiveCount.get() > 20) {
return new CommonJsonResponse("9999", "太快了");
}
num = receiveCount.incrementAndGet();
final String s = orderService.receiveOne(vo.getData());
return StringUtils.isEmpty(s) ? CommonJsonResponse.ok() : new CommonJsonResponse("9999", s);
} finally {
if (num != null) {
receiveCount.decrementAndGet();
}
}
}对于没有领取过该红包的用户，在红包没有过期且红包还有剩余的情况下，抢红包成功，记录成功标识入redis,设置标识过期时间为5秒。
public String receiveOne(ReqReceiveRedPacketVO data) {
final Long redPacketId = data.getPacketId();
final String redPacketNo = data.getPacketNo();
final String redisKey = REDPACKET_NUM_PREFIX + redPacketNo;
if (!redisTemplate.hasKey(redisKey)) {
return "红包已经过期";
}
final Integer num = (Integer) redisTemplate.opsForValue().get(redisKey);
if (num <= 0) {
return "红包已抢完";
}
RedPacketDetailExample example = new RedPacketDetailExample();
example.createCriteria().andPacketIdEqualTo(redPacketId)
.andReceivedEqualTo(1)
.andUserIdEqualTo(data.getUserId());
final List<RedPacketDetail> details = detailMapper.selectByExample(example);
if (!details.isEmpty()) {
return "该红包已经领取过了";
}
final String receiveKey = REDPACKET_RECEIVE_PREFIX + redPacketNo + ":" + data.getUserId();
//优化成lua脚本
String lua = "local i = redis.call('setnx',KEYS[1],ARGV[1])\r\n" +
"if i == 1 then \r\n" +
" local j = redis.call('expire',KEYS[1],ARGV[2])\r\n" +
"end \r\n" +
"return i";
//优化成lua脚本
final Long execute = redisTemplate.execute(new DefaultRedisScript<>(lua, Long.class), Arrays.asList(receiveKey), 1, 5);
if (execute != 1L) {
return "太快了";
}
return "";
}在用户抢红包成功标识未过期的状态下，且红包未过期红包未领完时，从数据库中领取一个红包，领取成功将领取记录写入redis以供查询过期时间为48小时。
@Transactional(rollbackFor = Exception.class)
public String openRedPacket(ReqReceiveRedPacketVO data) {
final Long packetId = data.getPacketId();
final String packetNo = data.getPacketNo();
final String userId = data.getUserId();
final String redisKey = REDPACKET_NUM_PREFIX + packetNo;
Long num = null;
try {
final String receiveKey = REDPACKET_RECEIVE_PREFIX + packetNo + ":" + userId;
if (!redisTemplate.hasKey(receiveKey)) {
log.info("未获取到红包资格，packet:{},user:{}", packetNo, userId);
throw new ServiceException("红包飞走了", ExceptionType.SYS_ERR);
}
redisTemplate.delete(receiveKey);
if (!redisTemplate.hasKey(redisKey)) {
log.info("红包过期了，packet:{}", packetNo);
throw new ServiceException("红包飞走了", ExceptionType.SYS_ERR);
}
num = redisTemplate.opsForValue().increment(redisKey, -1);
if (num < 0L) {
log.info("红包领完了，packet:{}", packetNo);
throw new ServiceException("红包飞走了", ExceptionType.SYS_ERR);
}
final int i = detailMapper.receiveOne(packetId, packetNo, userId);
if (i != 1) {
log.info("红包真的领完了，packet:{}", packetNo);
throw new ServiceException("红包飞走了", ExceptionType.SYS_ERR);
}
RedPacketDetailExample example = new RedPacketDetailExample();
example.createCriteria().andPacketIdEqualTo(packetId)
.andReceivedEqualTo(1)
.andUserIdEqualTo(userId);
final List<RedPacketDetail> details = detailMapper.selectByExample(example);
if (details.size() != 1) {
log.info("已经领取过了，packet:{}，user:{}", packetNo, userId);
throw new ServiceException("红包飞走了", ExceptionType.SYS_ERR);
}
//处理加款
log.info("抢到红包金额{}，packet:{}，user:{}", details.get(0).getAmount(), packetNo, userId);
final String listKey = REDPACKET_LIST_PREFIX + packetNo;
redisTemplate.opsForList().leftPush(listKey,details.get(0));
redisTemplate.expire(redisKey, 48, TimeUnit.HOURS);
return "" + details.get(0).getAmount();
} catch (Exception e) {
if (num != null) {
redisTemplate.opsForValue().increment(redisKey, 1L);
}
log.warn("打开红包异常", e);
throw new ServiceException("红包飞走了", ExceptionType.SYS_ERR);
}
}其中 detailMapper.receiveOne(packetId, packetNo, userId); sql如下，将指定红包记录下未领取的红包更新一条未当前用户已经领取，若成功更新一条则表示领取成功，否则领取失败。
update redpacket_detail d
set received = 1,update_time = now(),user_id = #{userId,jdbcType=VARCHAR}
where received = 0
and packet_id = #{packetId,jdbcType=BIGINT}
and packet_no = #{packetNo,jdbcType=VARCHAR}
and user_id is null
limit 1直接充redis中获取用户领取记录，没有则直接获取数据库并同步至redis。
public RespReceiveListVO receiveList(ReqReceiveListVO data) {
//红包记录redisKey
final String packetNo = data.getPacketNo();
final String redisKey = REDPACKET_LIST_PREFIX + packetNo;
if (!redisTemplate.hasKey(redisKey)) {
RedPacketDetailExample example = new RedPacketDetailExample();
example.createCriteria().andPacketNoEqualTo(packetNo)
.andReceivedEqualTo(1);
final List<RedPacketDetail> list = detailMapper.selectByExample(example);
redisTemplate.opsForList().leftPushAll(redisKey, list);
redisTemplate.expire(redisKey, 24, TimeUnit.HOURS);
}
List retList = redisTemplate.opsForList().range(redisKey, 0, -1);
final Object collect = retList.stream().map(item -> {
final JSONObject packetDetail = (JSONObject) item;
return ReceiveRecordVO.builder()
.amount(packetDetail.getBigDecimal("amount"))
.receiveTime(packetDetail.getDate("updateTime"))
.userId(packetDetail.getString("userId"))
.packetId(packetDetail.getLong("redpacketId"))
.packetNo(packetDetail.getString("redpacketNo"))
.build();
}).collect(Collectors.toList());
return RespReceiveListVO.builder().list((List) collect).build();
}设置jmeter参数1秒中并发请求50个抢11个红包，可以看到，前面的请求都是成功的，中间并发量上来后有部分达到并发上限被拦截，后面红包抢完请求全部失败。
上述就是小编为大家分享的springboot+websocket怎样实现并发抢红包功能了，如果刚好有类似的疑惑，不妨参照上述分析进行理解。如果想知道更多相关知识，欢迎关注亿速云行业资讯频道。
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