学习Spring Cloud Config 的时候，很容易遇到各种各样的问题，这里我就把我遇到的：Client 端读取不到Server端的配置文件中的属性总结一下。

首先我搭建了一个Eureka 注册中心，这里就不着重介绍了，不知道的小伙伴可以
网上查资料！

1.搭建Config 配置中心

POM 文件：

<?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> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.7.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.sg.config</groupId> <artifactId>config-demo</artifactId> <version>0.0.1-SNAPSHOT</version> <name>config-demo</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> <spring-cloud.version>Greenwich.SR2</spring-cloud.version> </properties> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-config-server</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> <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> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>

这里面Config用到的依赖是 spring-cloud-config-server ，其他自己看着引入即可

2.application.yml 的配置

server: port: 8095spring: application: name: config-demo cloud: config: server: git: uri: https://github.com/****/spring-cloud-demo.git username: password: search-paths: spring-cloud-demo-configeureka: client: service-url: defaultZone: http://127.0.0.1:8090/eureka/ register-with-eureka: true fetch-registry: true

Config Server 的配置主要是spring.cloud.config.server.git 下面的东西，其他按需配置即可。

3.Config Server 启动类

import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.client.discovery.EnableDiscoveryClient;import org.springframework.cloud.config.server.EnableConfigServer;@SpringBootApplication@EnableConfigServer@EnableDiscoveryClientpublic class ConfigDemoApplication { public static void main(String[] args) { SpringApplication.run(ConfigDemoApplication.class, args); }}

至此 Config Server 端就配置完成了。

4.配置Config Client 端

首先引入依赖

<?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> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.6.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.sg.eureka.client</groupId> <artifactId>eureka-client-demo</artifactId> <version>0.0.1-SNAPSHOT</version> <name>eureka-client-demo</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> <spring-cloud.version>Greenwich.SR2</spring-cloud.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>com.sg.common</groupId> <artifactId>spring-cloud-common</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-config --> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-config</artifactId> </dependency> </dependencies> <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> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>

主要有关的依赖是 spring-cloud-starter-config ，其他的按需引入即可

5.application.yml 配置文件

server: port: 8091spring: application: name: eureka-client-demo cloud: config: profile: test uri: http://127.0.0.1:8095/ label: master discovery: enabled: true service-id: config-demoeureka: client: register-with-eureka: true fetch-registry: true service-url: defaultZone: http://127.0.0.1:8090/eureka/### 端点控制management: endpoints: web: exposure: # 开启指定端点 include: hystrix.streamproject: name: hahha

启动类上什么配置也不用添加，就可以了，重要的一点：
1：如果用了Eureka ，则需要配置 spring.cloud.config.discovery.enable: true 和 spring.cloud.config.discovery.service-id: config-demo 这两个属性

6.读取Server中配置的属性

package com.sg.eureka.client.controller;import com.sg.common.vo.UserVO;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Value;import org.springframework.context.annotation.Configuration;import org.springframework.core.env.Environment;import org.springframework.web.bind.annotation.*;/** * @author liuhailong * @date 2019-08-08 */@RestController@RequestMapping(value = "users")@Configurationpublic class UserController { @Autowired private Environment environment; @Value("${project.name}") private String name; @GetMapping(value = "/config") public String getConfig(@RequestParam("key")String key){ return environment.getProperty(key); } @GetMapping(value = "/projectName") public String projectName(){ return name; }}

我这里用了 两种方式去读取配置文件中的内容
1：使用Spring core中的Environment 类 中的getProperty 可以取到
2：使用Spring 的 @Value("${project.name}") 注解

6.接下来验证一下：访问 http://localhost:8091/users/config?key=project.name 结果发现获取不到Config Server中配置的参数。主要原因：Spring Cloud 会首先加载bootstrap.yml 和bootstrap.properties 配置文件，然后再去加载spplication.properties 配置文件，所以在Config client 中的配置文件名称要修改为 bootstrap.yml 。然后在读取配置中心Config Server 中的 eureka-client-demo-test 的配置文件，这样就可以读取到了。