动态路由的实现方式多种多样，研究一下基于数据方式的动态路由。
1. 创建项目，并pom.xml文件引入如下依赖
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.olive</groupId> <artifactId>olive-gateway</artifactId> <version>0.0.1-SNAPSHOT</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.7.1</version> </parent> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>2021.0.3</version> <type>pom</type> <scope>import</scope> </dependency> <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-alibaba-dependencies</artifactId> <version>2021.1</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <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> </dependencies> </project>
使用 spring-boot-starter-paren t就不需要给子集pom配置版本号了，因为它包括了
- 定义了 java 编译版本为 1.8
- 使用 utf-8 格式编码
- 继承 spring-boot-dependencies 进行统一版本依赖管理
- 执行打包 war jar 操作配置；可以省略打包 plugin 的配置
- 自动化资源过滤。如 application.properties 和 application.yml 的资源过滤、 包括 profile 多环境配置的
- 自动化插件配置
- 不需要配置 maven 打包 plugin 插件配置
2. 从数据库加载路由配置
先定义一个接口，该接口的功能主要是返回数据库配置的所有路由
import org.springframework.cloud.gateway.route.RouteDefinition; import reactor.core.publisher.Flux; /** * 返回所有路由数据 */ public interface GatewayRouterService { Flux<RouteDefinition> getGatewayRoutes(); }
实现该接口
import java.util.ArrayList; import java.util.List; import org.springframework.cloud.gateway.route.RouteDefinition; import org.springframework.stereotype.Service; import com.olive.router.GatewayRouterService; import reactor.core.publisher.Flux; @Service public class RouterServiceImpl implements GatewayRouterService { @Override public Flux<RouteDefinition> getGatewayRoutes() { System.out.println("------getGatewayRoutes-------"); List<RouteDefinition> routes = null; //TODO查询数据库返回所有有效路由 return Flux.fromIterable(routes ); } }
3. 动态加载路由
实现 RouteDefinitionRepository 接口，Spring自动从数据库中读取路由配置；采用 nacos 作为服务发现与配置中心，nacos 自动触发心跳检测，网关基于心跳检测会自动刷新数据库路由配置，默认 30s 进行一次路由刷新。参考实现 RouteRefreshListener。
import org.springframework.cloud.gateway.route.RouteDefinition; import org.springframework.cloud.gateway.route.RouteDefinitionRepository; import com.olive.router.GatewayRouterService; import reactor.core.publisher.Flux; import reactor.core.publisher.Mono; public class DatabaseRouteDefinitionRepository implements RouteDefinitionRepository { private final GatewayRouterService gatewayRouterService; public InDBRouteDefinitionRepository(GatewayRouterService gatewayRouterService) { this.gatewayRouterService= gatewayRouterService; } @Override public Flux<RouteDefinition> getRouteDefinitions() { return gatewayRouterService.getGatewayRoutes(); } @Override public Mono<Void> save(Mono<RouteDefinition> route) { //TODO return Mono.empty(); } @Override public Mono<Void> delete(Mono<String> routeId) { //TODO return Mono.empty(); } }
4. 配置加载自定义的路由
spring-gateway 默认是先从 application.yml 文件加载路由配置；这里通过 AutoConfigureBefore 注解，加载数据库的路由配置。
import org.springframework.boot.autoconfigure.AutoConfigureBefore; import org.springframework.boot.autoconfigure.AutoConfigureOrder; import org.springframework.boot.autoconfigure.condition.ConditionalOnBean; import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean; import org.springframework.cloud.gateway.config.GatewayAutoConfiguration; import org.springframework.cloud.gateway.route.RouteDefinitionRepository; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.core.Ordered; import com.olive.route.DatabaseRouteDefinitionRepository; import com.olive.router.GatewayRouterService; @AutoConfigureBefore(GatewayAutoConfiguration.class) @AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 5) @Configuration public class GatewayConfig { /** * 网关路由配置实现bean */ @Bean @ConditionalOnMissingBean(RouteDefinitionRepository.class) @ConditionalOnBean(GatewayRouterService.class) public DatabaseRouteDefinitionRepository databaseRouteDefinitionRepository(GatewayRouterService gatewayRouterService) { return new DatabaseRouteDefinitionRepository(gatewayRouterService); } }
5. 添加 application.yml 配置文件
需要启动nacos，然后要配置 nacos 注册中心地址。
server: port: 8089 spring: application: name: olive-gateway cloud: nacos: discovery: server-addr: 192.168.255.10:8848
6. 编写 springboot 启动引导类
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; @EnableDiscoveryClient @SpringBootApplication public class GwApplication { public static void main(String[] args) { SpringApplication.run(GwApplication.class, args); } }
