摘要：
总之，以前的项目需要做电流限制：在几秒钟内杀死货物的界面。其他博客有很多关于使用谷歌插件的文章：guaue。如果是微服务，建议使用senilxxxx。我真的忘了。
总结一下，之前的一个项目需要做限流：秒杀商品的接口。
其他一些博客有很多文章介绍用谷歌的插件：guaue(针对于单机的)，如果是微服务的话推荐使用：senilxxxxx啥来的。具体有些忘记了。
这篇文章分享的内容是用redis+自定义注解+拦截器是实现限流（相对简单的一种）
废话不多说：首先reids的配置类：RedisConfig
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; @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 RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) { RedisTemplate<String, Object> 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：@RequestLimit
import java.lang.annotation.*; /** * 功能描述 * * @author yaoqihui * @version 2021/7/30 * @see [相关类/方法] * @since [malan-rabbitmq] */ @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; }
重点的过滤器拦截限流类：RequestLimitInterceptor
import com.fasterxml.jackson.databind.ObjectMapper; import com.sailmalan.malan.annotation.RequestLimit; import com.sailmalan.malan.utils.IpUtil; 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; @Component public class RequestLimitInterceptor implements HandlerInterceptor { private final Logger log = LoggerFactory.getLogger(this.getClass()); @Autowired private RedisTemplate<String, Object> redisTemplate; @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:{}",ipAddr, 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.info("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; } }
WebConfig类
import com.sailmalan.malan.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; @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"); } }
IpUtil工具类（获取客户端真实ip的工具类）
import javax.servlet.http.HttpServletRequest; import java.net.InetAddress; import java.net.UnknownHostException; 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 = ""; } return ipAddress; } }
RedisUtils类：（自己可以不写，如果代码里面报错，会使用redis的人可以自行替换）
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; import java.util.concurrent.TimeUnit; @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 { ValueOperations<Serializable, Object> operations = 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<Serializable, Object> 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<Serializable> 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<Serializable, Object> 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<String, Object, Object> 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<String, Object, Object> 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<String, Object> 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<Object> lRange(String k, long l, long l1) { ListOperations<String, Object> list = redisTemplate.opsForList(); return list.range(k, l, l1); } /** * Set集合添加 * * @param key * @param value */ public void add(String key, Object value) { SetOperations<String, Object> set = redisTemplate.opsForSet(); set.add(key, value); } /** * Set 集合获取 * * @param key * @return */ public Set<Object> setMembers(String key) { SetOperations<String, Object> set = redisTemplate.opsForSet(); return set.members(key); } /** * Sorted set :有序集合添加 * * @param key * @param value * @param scoure */ public void zAdd(String key, Object value, double scoure) { ZSetOperations<String, Object> zset = redisTemplate.opsForZSet(); zset.add(key, value, scoure); } /** * Sorted set:有序集合获取 * * @param key * @param scoure * @param scoure1 * @return */ public Set<Object> rangeByScore(String key, double scoure, double scoure1) { ZSetOperations<String, Object> zset = redisTemplate.opsForZSet(); return zset.rangeByScore(key, scoure, scoure1); } /** * 根据key获取Set中的所有值 * * @param key 键 * @return */ public Set<Integer> sGet(String key) { try { return redisTemplate.opsForSet().members(key); } catch (Exception e) { e.printStackTrace(); return null; } } /** * 根据value从一个set中查询,是否存在 * * @param key 键 * @param value 值 * @return true 存在 false不存在 */ public boolean sHasKey(String key, Object value) { try { return redisTemplate.opsForSet().isMember(key, value); } catch (Exception e) { e.printStackTrace(); return false; } } }
最后：接口测试。。。。
@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。";
}