利用spring如何实现接口限流
1.创建自定义注解
**
* 限流注解
*/
@Inherited
@Documented
@Target({ElementType.FIELD, ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface AccessLimit {
//限流唯一标识
String key() default "";
//限流时间
int time();
//限流次数
int count();
}
创建限流配置类
/**
* 注解拦截
*/
@Slf4j
@Aspect
@Configuration
public class AccessLimitConfig {
@Autowired
private RedisTemplate redisTemplate;
@Autowired
private DefaultRedisScript redisScript;
/**
* 执行redis的具体方法，限制method，保证没有其他的东西进来
*
* @return
*/
@Around("execution(* com.mayday.auth.controller ..*(..) )")
public Object interceptor(ProceedingJoinPoint joinPoint) throws Throwable {
MethodSignature signature = (MethodSignature) joinPoint.getSignature();
Method method = signature.getMethod();
Class targetClass = method.getDeclaringClass();
AccessLimit accessLimit = method.getAnnotation(AccessLimit.class);
if (accessLimit != null) {
//获取request对象
HttpServletRequest request = ((ServletRequestAttributes) Objects.requireNonNull(RequestContextHolder.getRequestAttributes())).getRequest();
String ipAddr = IpUtils.getIpAddr(request);
String string = ipAddr + "-" + targetClass.getName() + "- " + method.getName() + "-" + accessLimit.key();
List keys = Collections.singletonList(string);
Number number = redisTemplate.execute(redisScript, keys, accessLimit.count(), accessLimit.time());
if (number != null && number.intValue() != 0 && number.intValue() <= accessLimit.count()) {
return joinPoint.proceed();
}
} else {
return joinPoint.proceed();
}
return new Result(false, StatusCode.REPEAT_OPERATE);
}
}
3. 创建切面类
/**
* 限流配置
*/
@Slf4j @Component
public class AccessLimitAspect {
/**
* 读取限流脚本
*
* @return
*/
@Bean
public DefaultRedisScript redisLuaScript() {
DefaultRedisScript redisScript = new DefaultRedisScript<>();
redisScript.setScriptSource(new ResourceScriptSource(new ClassPathResource("redisLimit.lua")));
//返回类型郑州哪个妇科医院好 http://www.sptdfk.com/
redisScript.setResultType(Number.class);
return redisScript;
}
/**
* RedisTemplate
*
* @return
*/
@Bean
public RedisTemplate limitRedisTemplate(LettuceConnectionFactory redisConnectionFactory) {
RedisTemplate template = new RedisTemplate<>();
template.setKeySerializer(new StringRedisSerializer());
template.setValueSerializer(new GenericJackson2JsonRedisSerializer());
template.setConnectionFactory(redisConnectionFactory);
return template;
}
}
Lua脚本
--Lua脚本
--IP限流Lua脚本
--- 限流KEY资源唯一标识
local key = "rate.limit:" .. KEYS[1]
--- 时间窗最大并发数
local limit = tonumber(ARGV[1])
--- -过期时间
local expire_time = ARGV[2]
local is_exists = redis.call("EXISTS", key)
if is_exists == 1 then
if redis.call("INCR", key) > limit then
return 0
else
return 1
end
else
redis.call("SET", key, 1)
redis.call("EXPIRE", key, expire_time)
return 1
end