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Editor to share with you how Spring Boot uses interceptor and cache to complete interface anti-brushing. I believe most people don't know much about it, so share this article for your reference. I hope you will learn a lot after reading this article. Let's learn about it together.

Why do you need the interface to prevent brushing?

In order to reduce the pressure on the server, leave the server resources to valuable requests and prevent malicious access, general programs will have interface anti-brush settings. Next, a simple and flexible interface anti-brush operation is introduced.

Technical analysis

The main technology is interception + cache. We can mark and manage the interfaces that need to be brushed through custom annotations, and use cache statistics to specify the frequency at which a specific ip accesses a certain interface in a time interval. If it exceeds a certain threshold, let him enter the dark room for a while and automatically liberate when it expires.

Main code

Pre-environment building, Spring Boot project, introducing Web and Redis dependencies

Org.springframework.boot spring-boot-starter-parent 2.3.3.RELEASE org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-data-redis org.springframework.boot spring-boot-starter

Custom annotation

Define interceptor, override preHandler method

@ Override public boolean preHandle (HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {log.info ("- interface anti-brush interceptor -"); if (handler instanceof HandlerMethod) {HandlerMethod handlerMethod = (HandlerMethod) handler; AccessLimit accessLimit = handlerMethod.getMethodAnnotation (AccessLimit.class) / / if it is not in the anti-brush target, return if (accessLimit = = null) {return true;} / / to get the maximum number of visits int maxAccessCnt = accessLimit.maxAccessCnt (); / / get ip String key = getRealIp (request) / / the interface path of the ip+ request = > unique identification key key + = request.getRequestURI (); / / current visits Object value = redisTemplate.opsForValue () .get (key) If (value = = null) {/ / set the key retention time to 1s redisTemplate.opsForValue (). Set (key, 1,1L, TimeUnit.SECONDS);} else {Integer currentCnt = (Integer) value; if (currentCnt)

< maxAccessCnt) { //对应key值自增 redisTemplate.opsForValue().increment(key); } else { //超出接口时间段内允许访问的次数，直接返回错误信息,同时设置过期时间 20s自动剔除 redisTemplate.expire(key, 20L,TimeUnit.SECONDS); response.setContentType("application/json;charset=utf-8"); try { OutputStream out = response.getOutputStream(); out.write("访问次数已达上线！请稍后再访问".getBytes(StandardCharsets.UTF_8)); out.flush(); out.close(); } catch (IOException e) { e.printStackTrace(); } return false; } } } return true; } 添加到需要防刷的接口上 /** * 返回不携带data的（成功例子） * @return */@AccessLimit@GetMapping("/getPaperS")public ApiResult getPaperInfoSuccess() { if (log.isInfoEnabled()) { log.info("收到获取paper信息请求..."); } //...业务逻辑 if (log.isInfoEnabled()) { log.info("完成获取paper信息请求，准备返回对象信息"); } return ApiResultGenerator.success();}测试结果 正常情况下

When the maximum number of visits in the time period

The above is all the contents of the article "how to use interceptor and cache to complete interface anti-brushing in Spring Boot". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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