说明
本文通过 自定义注解 + Redis 实现接口限流。
实现
- 自定义注解
@Inherited
@Documented
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
// 默认就是60秒内可以访问2次
public @interface RequestLimit {
/**
* 时间，秒为单位
*/
int second() default 60;
/**
* second时间内允许访问的次数
*/
int maxCount() default 2;
}
- 通过AOP实现限流
@Configuration
@EnableAspectJAutoProxy
@Aspect
@Slf4j
@Order(-5) // 如果有多个AOP，需要将Order设置到最小，优先判断限流
public class RequestLimitAspect {
// 这里通过将访问信息保存在redis中，判断是否限流
@Autowired
private RedisTemplate<String, String> redisTemplate;
// 定义切点，所有添加RequestLimit注解的
@Pointcut(value = "@annotation(org.xxx.xxx.annotation.RequestLimit)")
private void handleRequestLimit() {
}
@Around("handleRequestLimit()")
public Object handleResponseEncrypt(ProceedingJoinPoint pjp) throws Throwable {
MethodSignature signature = (MethodSignature) pjp.getSignature();
Method method = signature.getMethod();
RequestLimit requestLimit = method.getAnnotation(RequestLimit.class);
// 没有添加注解直接放行
if (null == requestLimit) {
return pjp.proceed();
}
ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
// 获取HttpServletRequest
HttpServletRequest request = (HttpServletRequest) requestAttributes.resolveReference(RequestAttributes.REFERENCE_REQUEST);
// 获取公网IP
String ip = CommonUtils.getPublicIp(request);
// 实现同一个公网IP 限流
String key = "limit:" + ip + ":" + request.getServletPath();
String count = redisTemplate.opsForValue().get(key);
if (StringUtils.isEmpty(count)) {
count = "1";
redisTemplate.opsForValue().set(key, count, requestLimit.second(), TimeUnit.SECONDS);
return pjp.proceed();
}
if (Integer.valueOf(count) < requestLimit.maxCount()) {
redisTemplate.opsForValue().increment(key);
return pjp.proceed();
}
log.info("RemoteAddr:{} 请求接口:{} 请求过于频繁, 已拒绝请求.", ip, request.getServletPath());
HttpServletResponse response = requestAttributes.getResponse();
response.setCharacterEncoding("UTF-8");
response.setContentType("application/json; charset=utf-8");
response.getWriter()
// 触发限流自定义返回内容
.println(JSON.toJSONString(new Response(Constant.ResponseCode.RequestLimit, Constant.ResponseMsg.RequestLimit)));
return null;
}
}
- 获取公网IP
public static String getPublicIp(HttpServletRequest request) {
String ip = null;
try {
ip = request.getHeader("x-forwarded-for");
if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
ip = request.getHeader("Proxy-Client-IP");
}
if (StringUtils.isEmpty(ip) || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
ip = request.getHeader("WL-Proxy-Client-IP");
}
if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
ip = request.getHeader("HTTP_CLIENT_IP");
}
if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
ip = request.getHeader("HTTP_X_FORWARDED_FOR");
}
if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
ip = request.getRemoteAddr();
}
} catch (Exception e) {
log.error("getPublicIp ERROR ", e);
}
//使用代理，则获取第一个IP地址
if (StringUtils.isEmpty(ip) && ip.length() > 15) {
if (ip.indexOf(",") > 0) {
ip = ip.substring(0, ip.indexOf(","));
}
}
return ip;
}