防止接口恶意刷新和暴力请求

在实际项目使用中，必须要考虑服务的安全性，当服务部署到互联网以后，就要考虑服务被恶意请求和暴力攻击的情况，下面的教程，通过intercept和redis针对url+ip在一定时间内访问的次数来将ip禁用，可以根据自己的需求进行相应的修改；

首先工程为springboot框架搭建，不再详细叙述。直接上核心代码。

首先创建一个自定义的拦截器类，也是最核心的代码;

/**
 * @description: ip+url重复请求现在拦截器
 **/
@Slf4j
public class IpUrlLimitInterceptor implements HandlerInterceptor {
 
 
	private RedisUtil getRedisUtil() {
		return  SpringContextUtil.getBean(RedisUtil.class);
	}
 
	private static final String LOCK_IP_URL_KEY="lock_ip_";
 
	private static final String IP_URL_REQ_TIME="ip_url_times_";
 
	private static final long LIMIT_TIMES=5;
 
	private static final int IP_LOCK_TIME=60;
 
	@Override
	public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
		log.info("request请求地址uri={},ip={}", httpServletRequest.getRequestURI(), IpAdrressUtil.getIpAdrress(httpServletRequest));
		if (ipIsLock(IpAdrressUtil.getIpAdrress(httpServletRequest))){
			log.info("ip访问被禁止={}",IpAdrressUtil.getIpAdrress(httpServletRequest));
			ApiResult result = new ApiResult(ResultEnum.LOCK_IP);
			returnJson(httpServletResponse, JSON.toJSONString(result));
			return false;
		}
		if(!addRequestTime(IpAdrressUtil.getIpAdrress(httpServletRequest),httpServletRequest.getRequestURI())){
			ApiResult result = new ApiResult(ResultEnum.LOCK_IP);
			returnJson(httpServletResponse, JSON.toJSONString(result));
			return false;
		}
		return true;
	}
 
	@Override
	public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
 
	}
 
	@Override
	public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
 
	}
 
	/**
	 * @Description: 判断ip是否被禁用
	 */
	private Boolean ipIsLock(String ip){
		RedisUtil redisUtil=getRedisUtil();
		if(redisUtil.hasKey(LOCK_IP_URL_KEY+ip)){
			return true;
		}
		return false;
	}
	/**
	 * @Description: 记录请求次数
	 */
	private Boolean addRequestTime(String ip,String uri){
		String key=IP_URL_REQ_TIME+ip+uri;
		RedisUtil redisUtil=getRedisUtil();
		if (redisUtil.hasKey(key)){
			long time=redisUtil.incr(key,(long)1);
			if (time>=LIMIT_TIMES){
				redisUtil.getLock(LOCK_IP_URL_KEY+ip,ip,IP_LOCK_TIME);
				return false;
			}
		}else {
			redisUtil.getLock(key,(long)1,1);
		}
		return true;
	}
 
	private void returnJson(HttpServletResponse response, String json) throws Exception {
		PrintWriter writer = null;
		response.setCharacterEncoding("UTF-8");
		response.setContentType("text/json; charset=utf-8");
		try {
			writer = response.getWriter();
			writer.print(json);
		} catch (IOException e) {
			log.error("LoginInterceptor response error ---> {}", e.getMessage(), e);
		} finally {
			if (writer != null) {
				writer.close();
			}
		}
	}
 
 
}

代码中redis的使用的是分布式锁的形式，这样可以最大程度保证线程安全和功能的实现效果。代码中设置的是1S内同一个接口通过同一个ip访问5次，就将该ip禁用1个小时，根据自己项目需求可以自己适当修改，实现自己想要的功能；

redis分布式锁的关键代码:

@Component
@Slf4j
public class RedisUtil {
 
	private static final Long SUCCESS = 1L;
 
	@Autowired
	private RedisTemplate<String, Object> redisTemplate;
	// =============================common============================
 
	
 
	/**
	 * 获取锁
	 * @param lockKey
	 * @param value
	 * @param expireTime：单位-秒
	 * @return
	 */
	public boolean getLock(String lockKey, Object value, int expireTime) {
		try {
			log.info("添加分布式锁key={},expireTime={}",lockKey,expireTime);
			String script = "if redis.call('setNx',KEYS[1],ARGV[1]) then if redis.call('get',KEYS[1])==ARGV[1] then return redis.call('expire',KEYS[1],ARGV[2]) else return 0 end end";
			RedisScript<String> redisScript = new DefaultRedisScript<>(script, String.class);
			Object result = redisTemplate.execute(redisScript, Collections.singletonList(lockKey), value, expireTime);
			if (SUCCESS.equals(result)) {
				return true;
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return false;
	}
 
	/**
	 * 释放锁
	 * @param lockKey
	 * @param value
	 * @return
	 */
	public boolean releaseLock(String lockKey, String value) {
		String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
		RedisScript<String> redisScript = new DefaultRedisScript<>(script, String.class);
		Object result = redisTemplate.execute(redisScript, Collections.singletonList(lockKey), value);
		if (SUCCESS.equals(result)) {
			return true;
		}
		return false;
	}
 
}

最后将上面自定义的拦截器通过registry.addInterceptor添加一下，就生效了；

@Configuration
@Slf4j
public class MyWebAppConfig extends WebMvcConfigurerAdapter {
    @Bean
	IpUrlLimitInterceptor getIpUrlLimitInterceptor(){
    	return new IpUrlLimitInterceptor();
	}
 
 @Override
    public void addInterceptors(InterceptorRegistry registry) {
		registry.addInterceptor(getIpUrlLimitInterceptor()).addPathPatterns("/**");
        super.addInterceptors(registry);
    }
}

自己可以写一个for循环来测试方面的功能，这里就不详细介绍了；