java消息总线ibus_SpringCloud Bus 消息总线

一、能干嘛？

二、什么是总线？

三、动态刷新全局广播

注意：必须先具备良好的RabbitMQ环境

演示广播效果，增加复杂度，再以3355为模板再制作一个3366

1、新建cloud-config-client-3366

1)POM

cloud2020

com.atguigu.springcloud

1.0-SNAPSHOT

4.0.0

cloud-config-client-3366

8

8

org.springframework.cloud

spring-cloud-starter-config

org.springframework.cloud

spring-cloud-starter-netflix-eureka-client

com.atguigu.springcloud

cloud-api-commons

${project.version}

org.springframework.boot

spring-boot-starter-web

org.springframework.boot

spring-boot-starter-actuator

org.springframework.boot

spring-boot-devtools

runtime

true

org.projectlombok

lombok

true

org.springframework.boot

spring-boot-starter-test

test

pom文件

2)YML

server:

port: 3366

spring:

application:

name: config-client

cloud:

config:

label: master

name: config

profile: dev

uri: http://localhost:3344

eureka:

client:

service-url:

defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka

management:

endpoints:

web:

exposure:

include: “*”

3)主启动

@EnableEurekaClient

@SpringBootApplicationpublic classConfigClientMain3366 {public static voidmain(String[] args) {

SpringApplication.run( ConfigClientMain3366.class,args);

}

}

4)controller

@RestController

@RefreshScopepublic classConfigClientController {

@Value(“${server.port}”)privateString serverPort;

@Value(“${config.info}”)privateString configInfo;

@GetMapping(“/configInfo”)publicString getConfigInfo(){return “serverPort:”+serverPort+”\t\n\n configInfo: “+configInfo;

}

}

2、设计思想

1) 利用消息总线触发一个客户端/bus/refresh，进而刷新所有客户端的配置

2) 利用消息总线触发一个服务端ConfigServer的/bus/refresh端点，进而刷新所有客户端的配置(更加推荐)

图二的架构显然更加合适，图一不适合的原因如下

打破了微服务的职责单一性，因为微服务本身是业务模块，它本不应该承担配置刷新职责

破坏了微服务各节点的对等性

有一定的局限性。例如，微服务在迁移时，它的网络地址常常会发生变化，此时如果想要做到自动刷新，那就会增加更多的修改

3、代码改造

1)给cloud-config-center-3344配置中心服务端添加消息总线支持

POM

org.springframework.cloud

spring-cloud-starter-bus-amqp

增加mq依赖

YML

server:

port:3344spring:

application:

name: cloud-config-center

cloud:

config:

server:

git:

uri: https://github.com/jwen1994/sprincloud-config.git

search-paths:- springcloud-config

username:@.com

password: wj_

label: master

rabbitmq:

host:192.168.216.130

port: 5672username: admin

password: password

eureka:

client:

service-url:

defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka

management:

endpoints:

web:

exposure:

include: “bus-refresh”

2)给cloud-config-center-3355客户端添加消息总线支持

POM

org.springframework.cloud

spring-cloud-starter-bus-amqp

增加mq依赖

YML

server:

port:3355spring:

application:

name: config-client

cloud:

config:

label: master

name: config

profile: dev

uri: http://localhost:3344

rabbitmq:

host: 192.168.216.130

port: 5672username: admin

password: password

eureka:

client:

service-url:

defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka

management:

endpoints:

web:

exposure:

include:”*”

3)给cloud-config-center-3366客户端添加消息总线支持

POM

org.springframework.cloud

spring-cloud-starter-bus-amqp

增加mq依赖

YML

server:

port:3366spring:

application:

name: config-client

cloud:

config:

label: master

name: config

profile: dev

uri: http://localhost:3344

rabbitmq:

host:192.168.216.130port:5672username: admin

password: password

eureka:

client:

service-url:

defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka

management:

endpoints:

web:

exposure:

include:”*”

4、测试

修改Github上配置文件增加版本号

curl -X POST “http://localhost:3344/actuator/bus-refresh”

一次发送，处处生效

四、动态刷新定点通知

不想全部通知，只想定点通知

只通知3355

不通知3366

公式：http://配置中心IP地址/actuator/bus-refresh/{destination}

/bus/refresh请求不再发送到具体的服务实例上，而是发给config server并通过destination参数类指定需要更新配置的服务或实例

我们这里以刷新运行在3355端口上的config-client为例

curl -X POST “http://localhost:3344/actuator/bus-refresh/config-client:3355”

五、总结