Spring Boot + Redis实战-利用自定义注解+分布式锁实现接口幂等性

org.springframework.boot
    spring-boot-starter-data-redis

/**
 * @author Howinfun
 * @desc 自定义注解：分布式锁
 * @date 2019/11/12
 */
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface CacheLock {

    /** key前缀 */
    String prefix() default "";

    /** 过期秒数,默认为5秒 */
    int expire() default 5;

    /** 超时时间单位，默认为秒 */
    TimeUnit timeUnit() default TimeUnit.SECONDS;

    /** Key的分隔符（默认 :）  */
    String delimiter() default ":";
}

/**
 * @author Howinfun
 * @desc 自定义切面
 * @date 2019/11/12
 */
@Aspect
@Component
public class LockCheckAspect {

    /** lua */
    private static final String RELEASE_LOCK_LUA_SCRIPT = "if redis.call(‘get‘, KEYS[1]) == ARGV[1] then return redis.call(‘del‘, KEYS[1]) else return 0 end";

    @Autowired
    private RedisTemplate redisTemplate;

    // 增强带有CacheLock注解的方法
    @Pointcut("@annotation(cn.gdmcmc.system.api.config.aop.CacheLock)")
    public void pointCut(){}

    @Around("pointCut()")
    public Object around(ProceedingJoinPoint joinPoint) throws Throwable{

       // 可以根据业务获取用户唯一的个人信息，例如手机号码
       String phone = .....;
        
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        CacheLock cacheLock = method.getAnnotation(CacheLock.class);
        String prefix = cacheLock.prefix();
        if (StringUtils.isBlank(prefix)){
            throw new GlobalException("CacheLock prefix can‘t be null");
        }
        // 拼接 key
        String delimiter = cacheLock.delimiter();
        StringBuilder sb = new StringBuilder();
        sb.append(prefix).append(delimiter).append(phone);
        final String lockKey = sb.toString();
        final String UUID = cn.hutool.core.lang.UUID.fastUUID().toString();
        try {
            // 获取锁
            boolean success = redisTemplate.opsForValue().setIfAbsent(lockKey,UUID,cacheLock.expire(),cacheLock.timeUnit());
            if (!success){
                throw new CustomDeniedException("请勿重复提交");
            }
            Object result= joinPoint.proceed();
            return result;
        }finally {
            // 最后记得释放锁
            DefaultRedisScript redisScript = new DefaultRedisScript(RELEASE_LOCK_LUA_SCRIPT,Long.class);
            Long result = redisTemplate.execute(redisScript, Collections.singletonList(lockKey),UUID);
        }

    }
}

@RestController
@RequestMapping(value = "/charge")
@AllArgsConstructor
public class ChargeController {    
    
    @PostMapping("/startCharge")
    @CacheLock(prefix = "recharge")
    public Result startCharge(@RequestBody @Validated({ChargeQuery.QRCodeNotBlank.class}) ChargeQuery query){
        return this.chargeChargeService.startCharge(query);
    }
}