动态路由的好处

网关动态路可以从redis中取，或者nacos都可以。好处有：修了配置能够动态更新

依赖

    <dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-gateway</artifactId></dependency><!--nacos--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!--        配置中心来做配置管理--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId></dependency><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.47</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.10</version><optional>true</optional></dependency><dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId><version>5.4.7</version></dependency></dependencies><dependencyManagement><dependencies><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId><version>Hoxton.SR9</version><type>pom</type><scope>import</scope></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-alibaba-dependencies</artifactId><version>2.2.6.RELEASE</version><type>pom</type><scope>import</scope></dependency></dependencies></dependencyManagement>

配置类

这里可以从nacos注入，我是直接写死了

@Configuration
public class DynamicRouteConfig {public static final String NACOS_SERVICE_ADDR="localhost:8848";public static final String NACOS_SERVICE_NAMESPACE="7990000d-2835-42d9-86a6-76d998d8c5ea";public static final String NACOS_ROUTE_DATA_ID="route.json";public static final String NACOS_SROUTE_GROUP="DEFAULT_GROUP";
}

监听类与初始化

import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.event.RefreshRoutesEvent;
import org.springframework.cloud.gateway.route.RouteDefinition;
import org.springframework.cloud.gateway.route.RouteDefinitionLocator;
import org.springframework.cloud.gateway.route.RouteDefinitionWriter;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.stereotype.Service;
import org.springframework.util.CollectionUtils;
import reactor.core.publisher.Mono;import javax.annotation.Resource;
import java.util.List;@Service
@Slf4j
public class DynamicRouteServiceImpl implements ApplicationEventPublisherAware {@Resourceprivate RouteDefinitionWriter routeDefinitionWriter;@Resourceprivate RouteDefinitionLocator routeDefinitionLocator;@Resourceprivate ApplicationEventPublisher publisher;@Overridepublic void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {this.publisher =applicationEventPublisher;}public void delete(String id){try {log.info("gateway delete route id {}",id);this.routeDefinitionWriter.delete(Mono.just(id)).subscribe();this.publisher.publishEvent(new RefreshRoutesEvent(this));}catch (Exception e){}}public void updateList(List<RouteDefinition> definitions){log.info("gateway update route {}",definitions);List<RouteDefinition> routeDefinitionsExits = routeDefinitionLocator.getRouteDefinitions().buffer().blockFirst();if (!CollectionUtils.isEmpty(routeDefinitionsExits)){routeDefinitionsExits.forEach(routeDefinition ->{log.info("delete routeDefinition:{}",routeDefinition);delete(routeDefinition.getId());});}definitions.forEach(this::updateById);}private void updateById(RouteDefinition definition) {try {log.info("gateway update route {}",definition);this.routeDefinitionWriter.delete(Mono.just(definition.getId()));}catch (Exception e) {definition.getId();return;}try{routeDefinitionWriter.save(Mono.just(definition)).subscribe();this.publisher.publishEvent(new RefreshRoutesEvent(this));}catch (Exception e){}}public String addRoute(RouteDefinition definition){log.info("gateway add route {}",definition);routeDefinitionWriter.save(Mono.just(definition)).subscribe();this.publisher.publishEvent(new RefreshRoutesEvent(this));return "success";}}

import com.alibaba.fastjson.JSON;
import com.alibaba.nacos.api.NacosFactory;
import com.alibaba.nacos.api.config.ConfigService;
import com.alibaba.nacos.api.config.listener.Listener;
import com.alibaba.nacos.api.exception.NacosException;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang.StringUtils;
import org.springframework.cloud.gateway.route.RouteDefinition;
import org.springframework.context.annotation.DependsOn;
import org.springframework.stereotype.Component;import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.List;
import java.util.Properties;
import java.util.concurrent.Executor;@Component
@Slf4j
@DependsOn("dynamicRouteConfig")
public class DynamicRouteServiceImolByNacos {@Resourceprivate DynamicRouteServiceImpl dynamicRouteService;private ConfigService configService;@PostConstructpublic void init(){log.info("gateway route init......");try {configService=initConfigService();if (configService == null){log.info("gateway initConfigService fail");return;}String configInfo = configService.getConfig(DynamicRouteConfig.NACOS_ROUTE_DATA_ID,DynamicRouteConfig.NACOS_SROUTE_GROUP, 3000);if (StringUtils.isEmpty(configInfo)) {throw  new RuntimeException("ddd");}log.info("获取网关配置：\r\n{}",configInfo);List<RouteDefinition> definitionList = JSON.parseArray(configInfo, RouteDefinition.class);for (RouteDefinition definition : definitionList) {log.info("update route :{}",definition.toString());dynamicRouteService.addRoute(definition);}}catch (Exception e) {log.error("初始化网关路由时失败：",e);}dynamicRouteByNacosListener(DynamicRouteConfig.NACOS_ROUTE_DATA_ID,DynamicRouteConfig.NACOS_SROUTE_GROUP);}private void dynamicRouteByNacosListener(String dataId, String group) {try {configService.addListener(dataId, group, new Listener() {@Overridepublic Executor getExecutor() {log.info("getExecutor \r\n");return null;}@Overridepublic void receiveConfigInfo(String configInfo) {log.info("进行网关更新：\n\r{}",configInfo);List<RouteDefinition> definitionList = JSON.parseArray(configInfo, RouteDefinition.class);log.info("update route :{}",definitionList.toString());dynamicRouteService.updateList(definitionList);}});} catch (NacosException e) {log.error("从nacos 接受动态路由配置出错！！！：",e);}}private ConfigService initConfigService(){try {Properties properties = new Properties();properties.setProperty("serverAddr",DynamicRouteConfig.NACOS_SERVICE_ADDR);properties.setProperty("namespace",DynamicRouteConfig.NACOS_SERVICE_NAMESPACE);return NacosFactory.createConfigService(properties);}catch (Exception e){log.error("初始化网关路由时失败：",e);return null;}}}

效果

当nacos 路由文件修改之后，这里可以监听到。

总结

1-要想真正了解，需要了解Gateway源码。
2-了解一些，SPring 的反应式编程