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1.准备环境
eureka server: 注册中心
config server: 配置中心
config client: 配置客户端
2、开始踩坑
eureka server搭建不用说，很简单，引入netflix-eureka-server依赖就行了，然后配置注册中心，主程序加入注解就ok！
pom.xml
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
applicaiton.properties:
server.port= 8761
spring.application.name= eureka-server
eureka.client.service-url.default-zone = http://localhost:8761/eureka/
eureka.client.registry-fetch-interval-seconds=5000
eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false
applcation主程序：
package top.juntech.springcloudeurekaserver;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@SpringBootApplication
@EnableEurekaServer
public class SpringcloudEurekaServerApplication {
public static void main(String[] args) {
SpringApplication.run(SpringcloudEurekaServerApplication.class, args);
}
}
ok,eurekaserver就搭建好了，接下来我们搭建配置中心config-server
新建module ---->config-server--->引入config server依赖-------->配置文件-------》主程序加入注解
1、pom.xml
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Greenwich.SR2</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
2、application.yml(注释掉的部分是把配置中心文件放在git仓库的，为了方便，我们这里使用的是本地)
#server.port= 8763
#spring.application.name= config-server
#
##配置中心
#spring.cloud.config.server.git.uri= https://github.com/JunTech/springcloud-config-repo
#spring.cloud.config.server.git.password=
#spring.cloud.config.server.git.username=
#spring.cloud.config.server.git.search-paths=config-repo
#spring.cloud.config.label=master
server:
port: 8763
spring:
application:
name: config-server
profiles:
active: native
cloud:
config:
server:
native:
search-locations: classpath:/configRepo
3、在application.(*)文件当前目录下建立configRepo文件夹
search-locations: classpath:/configRepo 的意思是在configRepo文件夹下查找config client的配置文件
我们这里在文件夹configRepo中创建了一个文件：
config-client-dev.yml：
author: juntech
server:
port: 10007
注意，我把端口信息放在配置中心的！
4、主程序加入注解，声明为配置中心
package top.juntech.springcloudconfigserver;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.config.server.EnableConfigServer;
@SpringBootApplication
//加入注解声明为配置中心
@EnableConfigServer
public class SpringcloudConfigServerApplication {
public static void main(String[] args) {
SpringApplication.run(SpringcloudConfigServerApplication.class, args);
}
}
ok,配置中心我们也弄完了！
最后，到config client环节了！！！！
激动否。。。
config client搭建
流程和上面的一毛一样。
新建module ---->config-client--->引入config client、eureka client依赖-------->配置文件-------》主程序加入注解
1、pom.xml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 https://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>top.juntech</groupId>
<artifactId>springcloud-config-client</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springcloud-config-client</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>
<version>2.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2、bootstrap.yml(注意，这里必须是bootstrap.yml,不然会报错)
spring:
application:
name: config-client
profiles:
active: dev
cloud:
config:
uri: http://localhost:8763
eureka:
client:
service-url:
default-zone: http://localhost:8761/eureka/
3、主程序
package top.juntech.springcloudconfigclient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@SpringBootApplication
@RestController
@EnableDiscoveryClient
public class SpringcloudConfigClientApplication {
public static void main(String[] args) {
SpringApplication.run(SpringcloudConfigClientApplication.class, args);
}
@Value("${author}")
private String author;
@Value("${server.port}")
private String port;
@GetMapping("/hi")
public String hi(){
return "hi ,author : "+this.author+",i am from port : "+this.port;
}
}
3、总结
上面的3个module按照eurekaserver--->config server---->config client依次运行，在打开localhost:8761
显示如下：
Instances currently registered with Eureka
| Application | AMIs | Availability Zones | Status |
|---|---|---|---|
| CONFIG-CLIENT | n/a (1) | (1) | UP (1) - Ryan:config-client:10007 |
说明将config client注册到注册中心了，然后打开：http://localhost:10007/hi
hi ,author : juntech,i am from port : 10007
成功了。
总结如下：
发生Could not resolve placeholder* in value *错误的可能原因有以下几种：
-
配置中心profiles指定错误：
spring: application: name: config-server profiles: active: native在这里，我每次都是写到spring.profiles就回车，显示就成了
spring: application: name: config-server profiles: native （x） 这是错误的 -
config client必须每个配置文件都必须以 bootstrap.yml命名
之前我使用的是applicaiton.yml作为config client的配置文件，然后无一例外的都获取不到配置中心配置的server.port，每次运行都报错显示
启动 config-client报错 Could not resolve placeholder 'server.port' in value "${server.port}"
若还不能解决你的问题，可重构项目，参考我上面的代码，进行配置中心的config client的搭建！
4、参考资料
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