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简单的 springboot 限速器

时间:2020-03-18 17:58:05      阅读:236      评论:0      收藏:0      [点我收藏+]

1. 定义注解

// AccessLimit.java
import java.lang.annotation.*;

@Inherited
@Documented
@Target({ElementType.FIELD,ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface AccessLimit {

    //标识 指定sec时间段内的访问次数限制
    int limit() default 5;

    //标识 时间段
    int sec() default 5;

}

2. 定义拦截器

// AccessLimitInterceptor.java
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.annotation.Resource;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Method;
import java.util.concurrent.TimeUnit;

public class AccessLimitInterceptor implements HandlerInterceptor {
 
    //使用RedisTemplate操作redis
    @Resource
    private RedisTemplate<String,Integer> redisTemplate;
 
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        if (handler instanceof HandlerMethod) {
            HandlerMethod handlerMethod = (HandlerMethod) handler;
            Method method = handlerMethod.getMethod();
            if (!method.isAnnotationPresent(AccessLimit.class)) {
                return true;
            }
            AccessLimit accessLimit = method.getAnnotation(AccessLimit.class);
            if (accessLimit == null) {
                return true;
            }
            int limit = accessLimit.limit();
            int sec = accessLimit.sec();
            String key = IpUtil.getIpAddr(request) + request.getRequestURI();
            Integer maxLimit = redisTemplate.opsForValue().get(key);
            if (maxLimit == null) {
                //set时一定要加过期时间
                redisTemplate.opsForValue().set(key, 1, sec, TimeUnit.SECONDS);
            } else if (maxLimit < limit) {
                redisTemplate.opsForValue().set(key, maxLimit + 1, sec, TimeUnit.SECONDS);
            } else {
                output(response, "请求太频繁!");
            }
        }
        return true;
    }
 
    public void output(HttpServletResponse response, String msg) throws IOException {
        response.setContentType("application/json;charset=UTF-8");
        ServletOutputStream outputStream = null;
        try {
            outputStream = response.getOutputStream();
            outputStream.write(msg.getBytes("UTF-8"));
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            outputStream.flush();
            outputStream.close();
        }
    }
 
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
 
    }
 
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
 
    }
}

3. 加上注解

    @AccessLimit(limit = 5,sec = 24*60*60)    // 一日五次
    @RequestMapping(value = "/verify", method = {RequestMethod.POST, RequestMethod.GET})
    public void verify() throws ServletException, IOException {
        service.verify();
    }

参考文档:

https://blog.csdn.net/fanrenxiang/article/details/80683378

简单的 springboot 限速器

原文:https://www.cnblogs.com/sugare/p/12518304.html

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