SpringBoot + Redis 实现防刷限流

添加自定义AccessLimit注解，使用注解方式实现接口的限流操作

import java.lang.annotation.*;

/**
 * 接口防刷限流
 * 

 * 限流是通过拦截器实现
 *
 * @author H.Yang
 * @date 2022/12/14
 */
@Documented
@Target({ElementType.FIELD, ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface AccessLimit {

    /**
     * 指定second 时间内 API请求次数
     */
    int maxCount() default 5;

    /**
     * 请求次数的指定时间范围  秒数(redis数据过期时间)
     */
    int second() default 60;
}

编写拦截器

import cn.hutool.core.convert.Convert;
import com.xh.jedis.annotation.AccessLimit;
import com.xh.jedis.repository.JedisRepository;
import lombok.AllArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;

/**
 * API 接口防刷限流
 *
 * @author H.Yang
 * @date 2022/12/14
 */
@Slf4j
@AllArgsConstructor
public class AccessLimitInterceptor implements HandlerInterceptor {

    private final JedisRepository jedisRepository;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // Handler 是否为 HandlerMethod 实例
        if (handler instanceof HandlerMethod) {
            // 强转
            HandlerMethod handlerMethod = (HandlerMethod) handler;
            // 获取方法
            Method method = handlerMethod.getMethod();
            // 是否有AccessLimit注解
            if (!method.isAnnotationPresent(AccessLimit.class)) {
                return true;
            }
            // 获取注解内容信息
            AccessLimit accessLimit = method.getAnnotation(AccessLimit.class);
            if (accessLimit == null) {
                return true;
            }

            // 存储key
            String key = request.getRemoteAddr() + ":" + request.getContextPath() + ":" + request.getServletPath();

            // 已经访问的次数
            Integer count = Convert.toInt(jedisRepository.get(key), 0);
            System.out.println("已经访问的次数:" + count);
            if (count < 1) {
                jedisRepository.setex(key, "1", accessLimit.second());
                return true;
            }

            if (count < accessLimit.maxCount()) {
                jedisRepository.incr(key);
                return true;
            }

            if (count >= accessLimit.maxCount()) {
                log.warn("请求过于频繁请稍后再试");
                return false;
            }
        }

        return true;
    }

}

使用 AccessLimit

@Slf4j
@RestController
@RequestMapping("access")
public class AccessLimitController {
 
    /**
     * 限流测试
     */
    @GetMapping
    @AccessLimit(maxCount = 5,second = 60)
    public String limit(HttpServletRequest request) {
        log.info("Access Limit Test");
        return "限流测试";
    }
 
}