springcloud ( 6 分布式配置中心(Spring Cloud Config))
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分布式配置中心简介
在分布式系统中，由于服务数量巨多，为了方便服务配置文件统一管理，实时更新，所以需要分布式配置中心组件。在Spring Cloud中，有分布式配置中心组件spring cloud config ，它支持配置服务放在配置服务的内存中（即本地），也支持放在远程Git仓库中。在spring cloud config 组件中，分两个角色，一是config server，二是config client。
父工程
新建一个maven项目
pom.xml内容如下
4.0.0
com.cloud.shj
parent-config
1.0-SNAPSHOT
pom
config-server
config-client
org.springframework.boot
spring-boot-starter-parent
2.0.3.RELEASE
UTF-8
UTF-8
1.8
Finchley.RELEASE
org.springframework.boot
spring-boot-starter-test
test
org.springframework.cloud
spring-cloud-dependencies
${spring-cloud.version}
pom
import
org.springframework.boot
spring-boot-maven-plugin
新建config-server
在parent-config上新建一个springboot模块 config-server
pom.xml内容如下
4.0.0
com.cloud.shj
config-server
0.0.1-SNAPSHOT
jar
config-server
Demo project for Spring Boot
com.cloud.shj
parent-config
1.0-SNAPSHOT
org.springframework.boot
spring-boot-starter-web
org.springframework.cloud
spring-cloud-config-server
org.springframework.boot
spring-boot-maven-plugin
启动类如下
@SpringBootApplication
@EnableConfigServer
public class ConfigServerApplication {
public static void main(String[] args) {
SpringApplication.run(ConfigServerApplication.class, args);
}
}
配置文件内容如下
spring.application.name=config-server
server.port=8777
spring.cloud.config.server.git.uri=https://github.com/2213510339/springcloudConfig
spring.cloud.config.server.git.searchPaths=shj
spring.cloud.config.label=master
spring.cloud.config.server.git.username=
spring.cloud.config.server.git.password=其中:
- spring.cloud.config.server.git.uri：配置git仓库地址
- spring.cloud.config.server.git.searchPaths：配置仓库路径
- spring.cloud.config.label：配置仓库的分支
- spring.cloud.config.server.git.username：访问git仓库的用户名
- spring.cloud.config.server.git.password：访问git仓库的用户密码
如果Git仓库为公开仓库，可以不填写用户名和密码，如果是私有仓库需要填
启动项目,
访问配置信息的URL与配置文件的映射关系如下：
/{application}/{profile}[/{label}]
/{application}-{profile}.yml
/{label}/{application}-{profile}.yml
/{application}-{profile}.properties
/{label}/{application}-{profile}.properties
其中 application 指的是 config-server的名称,label指的是分支的名称,例如master,profile指的是环境的名称,例如dev开发环境配置文件,
test测试环境,pro正式环境
例如输入http://127.0.0.1:8777/config-server/dev/master
输入 http://127.0.0.1:8777/master/config-server-dev.properties
输入一个不存在的资源 http://127.0.0.1:8777/a/b
证明配置服务中心可以从远程程序获取配置信息。
构建 config-client
pom.xml内容
4.0.0
com.cloud.shj
config-client
0.0.1-SNAPSHOT
jar
config-client
Demo project for Spring Boot
com.cloud.shj
parent-config
1.0-SNAPSHOT
org.springframework.boot
spring-boot-starter-web
org.springframework.cloud
spring-cloud-starter-config
org.springframework.boot
spring-boot-maven-plugin
配置文件内容
spring.application.name=config-client
spring.cloud.config.label=master
spring.cloud.config.profile=dev
spring.cloud.config.uri= http://127.0.0.1:8777/
server.port=7888其中:
spring.cloud.config.label 指明远程仓库的分支
spring.cloud.config.profile 指明环境
spring.cloud.config.uri 指明配置服务中心的网址
启动类内容如下
@SpringBootApplication
@RestController
public class ConfigClientApplication {
public static void main(String[] args) {
SpringApplication.run(ConfigClientApplication.class, args);
}
@Value("${foo}")
String foo;
@RequestMapping("config")
public String config(){
return foo;
}
}启动项目,报错了
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'configClientApplication': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'foo' in value "${foo}"
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:379) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1350) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:580) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:503) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:760) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at com.cloud.shj.ConfigClientApplication.main(ConfigClientApplication.java:14) [classes/:na]
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'foo' in value "${foo}"
at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:172) ~[spring-core-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:124) ~[spring-core-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:237) ~[spring-core-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:211) ~[spring-core-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.lambda$processProperties$0(PropertySourcesPlaceholderConfigurer.java:175) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:839) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1086) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1065) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:584) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:91) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:373) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
... 17 common frames omitted
找了半天原因,没找到,于是更改了下端口
spring.application.name=config-server
server.port=8888
spring.cloud.config.server.git.uri=https://github.com/2213510339/springcloudConfig
spring.cloud.config.server.git.searchPaths=shj
spring.cloud.config.label=master
spring.cloud.config.server.git.username=
spring.cloud.config.server.git.password=
spring.application.name=config-client
spring.cloud.config.label=master
spring.cloud.config.profile=dev
spring.cloud.config.uri= http://localhost:8888/
server.port=8881
然后项目就正常跑走起来了,如果有大佬知道原因,请在下面留言解释,
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