前言
该篇介绍的内容如题,就是利用redis实现接口的限流( 某时间范围内 最大的访问次数 ) 。
正文
惯例,先看下我们的实战目录结构:
首先是pom.xml 核心依赖:
org.springframework.boot spring-boot-starter-data-redis org.apache.commons commons-pool2 org.springframework.boot spring-boot-starter-web
然后是application.yml里面的redis接入配置:
spring: redis: lettuce: pool: #连接池最大连接数 使用负值代表无限制 默认为8 max-active: 10 #最大空闲连接 默认8 max-idle: 10 #最小空闲连接 默认0 min-idle: 1 host: 127.0.0.1 password: 123456 port: 6379 database: 0 timeout: 2000ms server: port: 8710
redis的配置类, RedisConfig.java:
import com.fasterxml.jackson.annotation.JsonAutoDetect; import com.fasterxml.jackson.annotation.PropertyAccessor; import com.fasterxml.jackson.databind.ObjectMapper; import org.springframework.cache.CacheManager; import org.springframework.cache.annotation.EnableCaching; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.data.redis.cache.RedisCacheConfiguration; import org.springframework.data.redis.cache.RedisCacheManager; import org.springframework.data.redis.connection.RedisConnectionFactory; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.core.StringRedisTemplate; import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer; import org.springframework.data.redis.serializer.RedisSerializationContext; import org.springframework.data.redis.serializer.StringRedisSerializer; import static org.springframework.data.redis.cache.RedisCacheConfiguration.defaultCacheConfig; /** * @Author: JCccc * @CreateTime: 2018-09-11 * @Description: */ @Configuration @EnableCaching public class RedisConfig { @Bean public CacheManager cacheManager(RedisConnectionFactory connectionFactory) { RedisCacheConfiguration cacheConfiguration = defaultCacheConfig() .disableCachingNullValues() .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(new Jackson2JsonRedisSerializer(Object.class))); return RedisCacheManager.builder(connectionFactory).cacheDefaults(cacheConfiguration).build(); } @Bean public RedisTemplateredisTemplate(RedisConnectionFactory factory) { RedisTemplate redisTemplate = new RedisTemplate<>(); redisTemplate.setConnectionFactory(factory); Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class); ObjectMapper om = new ObjectMapper(); om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL); jackson2JsonRedisSerializer.setObjectMapper(om); //序列化设置 ,这样为了存储操作对象时正常显示的数据,也能正常存储和获取 redisTemplate.setKeySerializer(new StringRedisSerializer()); redisTemplate.setValueSerializer(jackson2JsonRedisSerializer); redisTemplate.setHashKeySerializer(new StringRedisSerializer()); redisTemplate.setHashValueSerializer(jackson2JsonRedisSerializer); return redisTemplate; } @Bean public StringRedisTemplate stringRedisTemplate(RedisConnectionFactory factory) { StringRedisTemplate stringRedisTemplate = new StringRedisTemplate(); stringRedisTemplate.setConnectionFactory(factory); return stringRedisTemplate; } }
自定义注解:
import java.lang.annotation.*; /** * @Author JCccc * @Description * @Date 2021/7/23 11:46 */ @Inherited @Documented @Target({ElementType.FIELD, ElementType.TYPE, ElementType.METHOD}) @Retention(RetentionPolicy.RUNTIME) public @interface RequestLimit { /** * 时间内 秒为单位 */ int second() default 10; /** * 允许访问次数 */ int maxCount() default 5; //默认效果 : 10秒内 对于使用该注解的接口,只能总请求访问数 不能大于 5次 }
接下来是拦截器 RequestLimitInterceptor.java:
拦截接口的方式 是通过 ip地址+接口url ,做时间内的访问计数
import com.elegant.testdemo.annotation.RequestLimit; import com.elegant.testdemo.utils.IpUtil; import com.fasterxml.jackson.databind.ObjectMapper; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.stereotype.Component; import org.springframework.web.method.HandlerMethod; import org.springframework.web.servlet.HandlerInterceptor; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.util.concurrent.TimeUnit; /** * @Author JCccc * @Description * @Date 2021/7/23 11:49 */ @Component public class RequestLimitInterceptor implements HandlerInterceptor { private final Logger log = LoggerFactory.getLogger(this.getClass()); @Autowired private RedisTemplateredisTemplate; @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { try { if (handler instanceof HandlerMethod) { HandlerMethod handlerMethod = (HandlerMethod) handler; // 获取RequestLimit注解 RequestLimit requestLimit = handlerMethod.getMethodAnnotation(RequestLimit.class); if (null==requestLimit) { return true; } //限制的时间范围 int seconds = requestLimit.second(); //时间内的 最大次数 int maxCount = requestLimit.maxCount(); String ipAddr = IpUtil.getIpAddr(request); // 存储key String key = ipAddr+":"+request.getContextPath() + ":" + request.getServletPath(); // 已经访问的次数 Integer count = (Integer) redisTemplate.opsForValue().get(key); log.info("检测到目前ip对接口={}已经访问的次数", request.getServletPath() , count); if (null == count || -1 == count) { redisTemplate.opsForValue().set(key, 1, seconds, TimeUnit.SECONDS); return true; } if (count < maxCount) { redisTemplate.opsForValue().increment(key); return true; } log.warn("请求过于频繁请稍后再试"); returnData(response); return false; } return true; } catch (Exception e) { log.warn("请求过于频繁请稍后再试"); e.printStackTrace(); } return true; } public void returnData(HttpServletResponse response) throws IOException { response.setCharacterEncoding("UTF-8"); response.setContentType("application/json; charset=utf-8"); ObjectMapper objectMapper = new ObjectMapper(); //这里传提示语可以改成自己项目的返回数据封装的类 response.getWriter().println(objectMapper.writeValueAsString("请求过于频繁请稍后再试")); return; } }
接下来是 拦截器的配置 WebConfig.java:
import com.elegant.testdemo.interceptor.RequestLimitInterceptor; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Configuration; import org.springframework.web.servlet.config.annotation.InterceptorRegistry; import org.springframework.web.servlet.config.annotation.WebMvcConfigurer; /** * @Author JCccc * @Description * @Date 2021/7/23 11:52 */ @Configuration public class WebConfig implements WebMvcConfigurer { @Autowired private RequestLimitInterceptor requestLimitInterceptor; @Override public void addInterceptors(InterceptorRegistry registry) { registry.addInterceptor(requestLimitInterceptor) //拦截所有请求路径 .addPathPatterns("/**") //再设置 放开哪些路径 .excludePathPatterns("/static/**","/auth/login"); } }
最后还有两个工具类
import javax.servlet.http.HttpServletRequest; import java.net.InetAddress; import java.net.UnknownHostException; /** * @Author : JCccc * @CreateTime : 2018-11-23 * @Description : * @Point: Keep a good mood **/ public class IpUtil { public static String getIpAddr(HttpServletRequest request) { String ipAddress = null; try { ipAddress = request.getHeader("x-forwarded-for"); if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) { ipAddress = request.getHeader("Proxy-Client-IP"); } if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) { ipAddress = request.getHeader("WL-Proxy-Client-IP"); } if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) { ipAddress = request.getRemoteAddr(); if (ipAddress.equals("127.0.0.1")) { // 根据网卡取本机配置的IP InetAddress inet = null; try { inet = InetAddress.getLocalHost(); } catch (UnknownHostException e) { e.printStackTrace(); } ipAddress = inet.getHostAddress(); } } // 对于通过多个代理的情况,第一个IP为客户端真实IP,多个IP按照','分割 if (ipAddress != null && ipAddress.length() > 15) { // "***.***.***.***".length() // = 15 if (ipAddress.indexOf(",") > 0) { ipAddress = ipAddress.substring(0, ipAddress.indexOf(",")); } } } catch (Exception e) { ipAddress=""; } // ipAddress = this.getRequest().getRemoteAddr(); return ipAddress; } }
RedisUtil :
import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.redis.core.*; import org.springframework.stereotype.Component; import java.io.Serializable; import java.util.List; import java.util.Set; @Component public class RedisUtils { @Autowired private RedisTemplate redisTemplate; /** * 写入String型 [ 键,值] * * @param key * @param value * @return */ public boolean set(final String key, Object value) { boolean result = false; try { ValueOperationsoperations = redisTemplate.opsForValue(); operations.set(key, value); result = true; } catch (Exception e) { e.printStackTrace(); } return result; } /** * 写入String型,顺便带有过期时间 [ 键,值] * * @param key * @param value * @return */ public boolean setWithTime(final String key, Object value,int seconds) { boolean result = false; try { ValueOperations operations = redisTemplate.opsForValue(); operations.set(key, value,seconds, TimeUnit.SECONDS); result = true; } catch (Exception e) { e.printStackTrace(); } return result; } /** * 批量删除对应的value * * @param keys */ public void remove(final String... keys) { for (String key : keys) { remove(key); } } /** * 批量删除key * * @param pattern */ public void removePattern(final String pattern) { Set keys = redisTemplate.keys(pattern); if (keys.size() > 0) redisTemplate.delete(keys); } /** * 删除对应的value * * @param key */ public void remove(final String key) { if (exists(key)) { redisTemplate.delete(key); } } /** * 判断缓存中是否有对应的value * * @param key * @return */ public boolean exists(final String key) { return redisTemplate.hasKey(key); } /** * 读取缓存 * * @param key * @return */ public Object get(final String key) { Object result = null; ValueOperations operations = redisTemplate.opsForValue(); result = operations.get(key); return result; } /** * 哈希 添加 * hash 一个键值(key->value)对集合 * * @param key * @param hashKey * @param value */ public void hmSet(String key, Object hashKey, Object value) { HashOperations hash = redisTemplate.opsForHash(); hash.put(key, hashKey, value); } /** * Hash获取数据 * * @param key * @param hashKey * @return */ public Object hmGet(String key, Object hashKey) { HashOperations hash = redisTemplate.opsForHash(); return hash.get(key, hashKey); } /** * 列表添加 * list:lpush key value1 * * @param k * @param v */ public void lPush(String k, Object v) { ListOperations list = redisTemplate.opsForList(); list.rightPush(k, v); } /** * 列表List获取 * lrange: key 0 10 (读取的个数 从0开始 读取到下标为10 的数据) * * @param k * @param l * @param l1 * @return */ public List
最后写个测试接口
TestController.java
import com.elegant.testdemo.annotation.RequestLimit; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; /** * @Author JCccc * @Description * @Date 2021/7/23 11:55 */ @RestController public class TestController { @GetMapping("/test") @RequestLimit(maxCount = 3,second = 60) public String test() { return "你好,如果对你有帮助,请点赞加关注。"; } }
这个/test接口的注解,我们设置的是 60秒内 最大访问次数为 3次 (实际应用应该是根据具体接口做相关的次数限制。)
然后使用postman测试一下接口:
前面三次都是请求通过的:
第四次:
ok,就先到这。
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