操作在数据库,使用MQ异步落库
@Autowired
private TicketService ticketService;
@PostMapping(“/grab”)
public ResponseEntity grabTicket(
@RequestParam Long scenicId,
@RequestParam Long userId) {
boolean success = ticketService.grab(scenicId, userId);
return success ?
ResponseEntity.ok(“抢票成功”) :
ResponseEntity.badRequest().body(“抢票失败”);
}

@Service
public class TicketService {
@Autowired
private StringRedisTemplate redisTemplate;

// @Autowired
// private RocketMQTemplate rocketMQTemplate;
private static final DefaultRedisScript SCRIPT;

static {
SCRIPT = new DefaultRedisScript<>();
SCRIPT.setResultType(Long.class);
SCRIPT.setScriptText(
“if redis.call(‘SISMEMBER’, KEYS[2], ARGV[1]) == 1 then return -1 end “ +
“local stock = tonumber(redis.call(‘GET’, KEYS[1])) “ +
“if stock <= 0 then return 0 end “ +
“redis.call(‘DECR’, KEYS[1]) “ +
“redis.call(‘SADD’, KEYS[2], ARGV[1]) “ +
“return 1”
);
}

public boolean grab(Long scenicId, Long userId) {
// 抢票前先预热库存
//redisTemplate.opsForValue().set(“ticket:stock:” + scenicId, “100”);
//redisTemplate.delete(“ticket:user:” + scenicId);

String stockKey = "ticket:stock:" + scenicId;
String userKey = "ticket:user:" + scenicId;
Long result = redisTemplate.execute(
        SCRIPT,
        Arrays.asList(stockKey, userKey),
        userId.toString()
);
if (result == null || result != 1) {
    return false;
}
// 异步下单

// rocketMQTemplate.convertAndSend(
// “ticket-order-topic”,
// new TicketOrderMsg(scenicId, userId)
// );
return true;
}

}