从本文开始，笔者将总结 spring cloud 相关内容的教程
版本选择
为了适应 java8，笔者选择了下面的版本，后续会出 java17的以SpringBoot3.0.X为主的教程
SpringBoot 版本 2.6.5
SpringCloud 版本 2021.0.1
SpringCloudAlibaba 版本 2021.0.1.0
SpringCloudAlibaba github 版本说明截图
SpringCloud 官网：https://spring.io/projects/spring-cloud
Spring Cloud Alibaba 官网：https://sca.aliyun.com/zh-cn/
目录
1、环境准备
2、项目创建
3、测试限流
4、改进限流返回
5、项目代码
1、环境准备
本文讲解Spring Cloud Gateway 使用 Redis 限流，注册中心使用 Nacos
Macos 官网：https://nacos.io/zh-cn/index.html
Nacos 安装这里不做过多介绍，不了解的朋友可以参考
Nacos 单机安装：https://blog.csdn.net/wsjzzcbq/article/details/123916233
Nacos 集群安装：https://blog.csdn.net/wsjzzcbq/article/details/123956116
笔者使用 docker 开启 nacos 和 redis
Spring Cloud Alibaba 2021.0.1.0 版本对应的nacos版本是 1.4.2
笔者使用的 Naocs 版本是 2.0.0-bugfix，redis 版本是 7.0.6
2、项目创建
新建 maven 聚合项目 cloud-learn
最外层父工程 cloud-learn 的 pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.wsjzzcbq</groupId><artifactId>cloud-learn</artifactId><version>1.0-SNAPSHOT</version><modules><module>gateway-learn</module><module>consumer-learn</module></modules><packaging>pom</packaging><repositories><repository><id>naxus-aliyun</id><name>naxus-aliyun</name><url>https://maven.aliyun.com/repository/public</url><releases><enabled>true</enabled></releases><snapshots><enabled>false</enabled></snapshots></repository></repositories><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.6.5</version><relativePath/></parent><properties><spring-cloud.version>2021.0.1</spring-cloud.version><spring-cloud-alibaba.version>2021.0.1.0</spring-cloud-alibaba.version><alibaba-nacos-discovery.veriosn>2021.1</alibaba-nacos-discovery.veriosn><alibaba-nacos-config.version>2021.1</alibaba-nacos-config.version><spring-cloud-starter-bootstrap.version>3.1.1</spring-cloud-starter-bootstrap.version></properties><dependencyManagement><dependencies><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId><version>${spring-cloud.version}</version><type>pom</type><scope>import</scope></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-alibaba-dependencies</artifactId><version>${spring-cloud-alibaba.version}</version><type>pom</type><scope>import</scope></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId><version>${alibaba-nacos-discovery.veriosn}</version></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId><version>${alibaba-nacos-config.version}</version></dependency><!--spring-cloud-dependencies 2020.0.0 版本不在默认加载bootstrap文件，如果需要加载bootstrap文件需要手动添加依赖--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-bootstrap</artifactId><version>${spring-cloud-starter-bootstrap.version}</version></dependency><dependency><groupId>com.alibaba.fastjson2</groupId><artifactId>fastjson2</artifactId><version>2.0.40</version></dependency></dependencies></dependencyManagement><dependencies><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency></dependencies></project>然后创建2个子工程 consumer-learn 和 gateway-learn
gateway-learn 中配置路由转发到 consumer-learn
consumer-learn 工程 pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>cloud-learn</artifactId><groupId>com.wsjzzcbq</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>consumer-learn</artifactId><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><!--feign负载均衡--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-loadbalancer</artifactId></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build>
</project>consumer-learn 工程 启动类
package com.wsjzzcbq;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.openfeign.EnableFeignClients;/*** ConsumerApplication** @author wsjz* @date 2023/09/17*/
@EnableFeignClients
@SpringBootApplication
public class ConsumerApplication {public static void main(String[] args) {SpringApplication.run(ConsumerApplication.class, args);}
}
consumer-learn 工程 配置文件
spring.application.name=consumer-learn
server.port=8081
spring.cloud.nacos.discovery.username=nacos
spring.cloud.nacos.discovery.password=nacos
spring.cloud.nacos.discovery.server-addr=192.168.31.152:8848
spring.cloud.nacos.discovery.namespace=public
logging.level.com.alibaba.cloudlearnconsumer.feign.ProducerService=DEBUG
consumer-learn 工程 controller
package com.wsjzzcbq.controller;import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;/*** ConsumerController** @author wsjz* @date 2023/09/17*/
@RestController
public class ConsumerController {@RequestMapping("/name")public String user() {return "宝剑锋从磨砺出，梅花香自苦寒来";}
}
gateway-learn
gateway-learn 工程 pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>cloud-learn</artifactId><groupId>com.wsjzzcbq</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>gateway-learn</artifactId><dependencies><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-gateway</artifactId></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!-- gateway负载均衡需要下面依赖，不添加会报错503--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-loadbalancer</artifactId></dependency><!--redis使用较高版本，5以上版本，不要使用windows版redis，低版本redis不支持lua中的命令--><!--https://blog.csdn.net/wxxiangge/article/details/95024214/--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis-reactive</artifactId></dependency><dependency><groupId>com.alibaba.fastjson2</groupId><artifactId>fastjson2</artifactId></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>gateway-learn 工程 启动类
package com.wsjzzcbq;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;/*** GatewayApplication** @author wsjz* @date 2023/09/17*/
@SpringBootApplication
public class GatewayApplication {public static void main(String[] args) {SpringApplication.run(GatewayApplication.class, args);}
}
限流需要实现 KeyResolver 接口的 resolve 方法
在 resolve 方法中返回限流的维度，如请求路径、ip地址、请求参数等
笔者这里限流维度是请求路径
package com.wsjzzcbq.limit;import org.springframework.cloud.gateway.filter.ratelimit.KeyResolver;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;/*** ApiKeyResolver** @author wsjz* @date 2023/09/17*/
@Component
public class ApiKeyResolver implements KeyResolver {@Overridepublic Mono<String> resolve(ServerWebExchange exchange) {System.out.println("API限流: " + exchange.getRequest().getPath().value());return Mono.just(exchange.getRequest().getPath().value());}
}
gateway-learn 工程 配置文件
server:port: 9000
spring:application:name: gateway-learnredis:host: 192.168.31.152password: 123456timeout: 5000database: 0cloud:nacos:discovery:server-addr: http://192.168.31.152:8848gateway:routes:- id: consumer-learnuri: lb://consumer-learnpredicates:- Path=/cloudlearn/consumer/**filters:- name: RequestRateLimiterargs:key-resolver: "#{@apiKeyResolver}"redis-rate-limiter.replenishRate: 1 #生成令牌速率：个/秒redis-rate-limiter.burstCapacity: 2 #令牌桶容量redis-rate-limiter.requestedTokens: 1 #每次消费的Token数量，默认是 1- StripPrefix=2配置说明：
RequestRateLimiter 是 gateway 提供的限流过滤器
#{@apiKeyResolver} 是笔者实现的 ApiKeyResolver
redis-rate-limiter.replenishRate 生成令牌的速率每秒几个
redis-rate-limiter.burstCapacity 令牌桶容量
redis-rate-limiter.requestedTokens 每次消费的令牌数量
当请求到网关以 /cloudlearn/consumer/ 为开头前缀时，会路由到 consumer-learn 服务上
创建完成的项目结构
3、测试限流
分别启动 consumer-learn 和 gateway-learn
登录 Nacos 控制台查看
启动成功后，可在Naocs 控制台查看注册服务信息
浏览器访问测试限流：http://localhost:9000/cloudlearn/consumer/name
运行效果
可以看到当1秒钟内请求超过2次时会被限流
4、改进限流返回
上面代码实现了限流，但限流触发后返回的是429，不利于前端处理，这里我们可以在默认的限流过滤器基础上进行改进，自定义限流时的返回
新建 NewRequestRateLimiterGatewayFilterFactory 类
继承默认的 RequestRateLimiterGatewayFilterFactory
package com.wsjzzcbq.filter;import com.alibaba.fastjson2.JSONObject;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.RequestRateLimiterGatewayFilterFactory;
import org.springframework.cloud.gateway.filter.ratelimit.KeyResolver;
import org.springframework.cloud.gateway.filter.ratelimit.RateLimiter;
import org.springframework.cloud.gateway.route.Route;
import org.springframework.cloud.gateway.support.HttpStatusHolder;
import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import reactor.core.publisher.Mono;import java.nio.charset.StandardCharsets;
import java.util.Iterator;
import java.util.Map;/*** NewRequestRateLimiterGatewayFilterFactory** @author wsjz* @date 2023/09/17*/
@Component
public class NewRequestRateLimiterGatewayFilterFactory extends RequestRateLimiterGatewayFilterFactory {private final RateLimiter defaultRateLimiter;private final KeyResolver defaultKeyResolver;private boolean denyEmptyKey = true;private String emptyKeyStatusCode = HttpStatus.FORBIDDEN.name();public NewRequestRateLimiterGatewayFilterFactory(RateLimiter defaultRateLimiter, KeyResolver defaultKeyResolver) {super(defaultRateLimiter, defaultKeyResolver);this.defaultRateLimiter = defaultRateLimiter;this.defaultKeyResolver = defaultKeyResolver;}@Overridepublic GatewayFilter apply(Config config) {System.out.println("过滤限流");KeyResolver resolver = (KeyResolver)this.getOrDefault(config.getKeyResolver(), this.defaultKeyResolver);RateLimiter<Object> limiter = (RateLimiter)this.getOrDefault(config.getRateLimiter(), this.defaultRateLimiter);boolean denyEmpty = (Boolean)this.getOrDefault(config.getDenyEmptyKey(), this.denyEmptyKey);HttpStatusHolder emptyKeyStatus = HttpStatusHolder.parse((String)this.getOrDefault(config.getEmptyKeyStatus(), this.emptyKeyStatusCode));return (exchange, chain) -> {return resolver.resolve(exchange).defaultIfEmpty("____EMPTY_KEY__").flatMap((key) -> {if ("____EMPTY_KEY__".equals(key)) {if (denyEmpty) {ServerWebExchangeUtils.setResponseStatus(exchange, emptyKeyStatus);return exchange.getResponse().setComplete();} else {return chain.filter(exchange);}} else {String routeId = config.getRouteId();if (routeId == null) {Route route = (Route)exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR);routeId = route.getId();}return limiter.isAllowed(routeId, key).flatMap((response) -> {Iterator var4 = response.getHeaders().entrySet().iterator();while(var4.hasNext()) {Map.Entry<String, String> header = (Map.Entry)var4.next();exchange.getResponse().getHeaders().add((String)header.getKey(), (String)header.getValue());}if (response.isAllowed()) {return chain.filter(exchange);} else {ServerHttpResponse httpResponse = exchange.getResponse();httpResponse.getHeaders().set("Content-Type", "application/json");JSONObject json = new JSONObject();json.put("code", 0);json.put("msg", "当前请求人数较多，请稍后再访问");DataBuffer dataBuffer = httpResponse.bufferFactory().wrap(json.toJSONString().getBytes(StandardCharsets.UTF_8));return httpResponse.writeWith(Mono.just(dataBuffer));}});}});};}private <T> T getOrDefault(T configValue, T defaultValue) {return configValue != null ? configValue : defaultValue;}
}
修改配置文件
配置我们自定义的限流过滤器
server:port: 9000
spring:application:name: gateway-learnredis:host: 192.168.31.152password: 123456timeout: 5000database: 0cloud:nacos:discovery:server-addr: http://192.168.31.152:8848gateway:routes:- id: consumer-learnuri: lb://consumer-learnpredicates:- Path=/cloudlearn/consumer/**filters:- name: NewRequestRateLimiterargs:key-resolver: "#{@apiKeyResolver}"redis-rate-limiter.replenishRate: 1 #生成令牌速率：个/秒redis-rate-limiter.burstCapacity: 2 #令牌桶容量redis-rate-limiter.requestedTokens: 1 #每次消费的Token数量- StripPrefix=2重新启动 gateway-learn
请求测试
5、项目代码
码云地址：https://gitee.com/wsjzzcbq/csdn-blog/tree/master/cloud-learn
至此完
![堆/二叉堆详解[C/C++]](https://img-blog.csdnimg.cn/4f07332950684248bc22b83333581e33.gif#pic_center)
