如何用Spring Gateway结合Nacos动态调整数据库长尾词路由？

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动态路由的实现方式多种多样，以下是一些基于数据方式的动态路由研究：

1. 创建项目，并在pom.xml文件中引入以下依赖：

xml

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="maven.apache.org/POM/4.0.0" xmlns:xsi="www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="maven.apache.org/POM/4.0.0 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

importorg.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;importjava.util.List;
import org.springframework.cloud.gateway.route.RouteDefinition;
importorg.springframework.stereotype.Service;
importcom.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
returnFlux.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;
importorg.springframework.cloud.gateway.route.RouteDefinitionRepository;
importcom.olive.router.GatewayRouterService;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
publicclassDatabaseRouteDefinitionRepositoryimplementsRouteDefinitionRepository{
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;
importcom.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
publicclassGwApplication{
public static void main(String[] args) {
SpringApplication.run(GwApplication.class, args);
}
}