消息总线

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消息总线

dalaoyang 2018-04-24 15:27:00 浏览877
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SpringCloudBus:事件、消息总线,用于在集群(例如,配置变化事件)中传播状态变化,可与Spring Cloud Config联合实现热部署。

在上一篇写出了springcloud对微服务的集中配置,那么就出现了一个问题,如果修改配置了怎么实现不需重启服务来实现配置的更新,下面有集中解决方法。

1.使用/refresh手动刷新配置

缺点:单点刷新,如果集群服务多的话,无论是工作量还是维护上都十分麻烦。

使用上一篇的config-client服务,加入依赖,

spring-boot-starter-actuator

pom文件如下:

<?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>

    <groupId>com.dalaoyang</groupId>
    <artifactId>springcloud_config_client</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springcloud_config_client</name>
    <description>springcloud_config_client</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Edgware.SR1</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</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>

在Controller类上加入@RefreshScope注解,由于上一篇controller写在了启动类上,所以直接加在启动类上,代码如下:

package com.dalaoyang;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
@RefreshScope
public class SpringcloudConfigClientApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringcloudConfigClientApplication.class, args);
    }


    @Value("${title}")
    String title;

    @RequestMapping("/getTitle")
    public String getTitle(){
        return title;
    }

}

配置文件新增配置management.security.enabled=false,在刷新时关闭安全验证。

代码如下:

spring.application.name=config-client
spring.cloud.config.label=master
spring.cloud.config.profile=test
spring.cloud.config.uri= http://localhost:9000/

##注册中心地址
eureka.client.service-url.defaultZone=http://eureka.dalaoyang.cn/eureka/

## 刷新时,关闭安全验证
management.security.enabled=false

分别启动项目config-server,config-client。访问http://localhost:8080/getTitle,结果如下图

9953332-0fc784d9c9da643f
image

修改git上配置,修改为dalaoyang_test_change,在次请求,结果没有改变,使用postman或者其他工具post请求http://localhost:8080/getTitle看到返回如下结果。

9953332-aa6563b0236cd221
image

在次访问http://localhost:8080/getTitle,如下图

9953332-407c574eb9ed38f6
image

2.使用springcloudbus刷新配置

springcloudbus需要使用轻量消息代理,本文使用rabbitmq,启动rabbitmq如下图:

9953332-f798d882454cddae
image

访问http://localhost:15672/#/如下图

9953332-727d442c5812aa80
image

新建项目springcloud_bus,同时改造config-client,pom文件加入bus依赖,代码如下:

<?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>

    <groupId>com.dalaoyang</groupId>
    <artifactId>springcloud_bus</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springcloud_bus</name>
    <description>springcloud_bus</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Edgware.SR1</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bus-amqp</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>

加入rabbitmq配置,配置文件如下:

spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest

##端口号
server.port=8881

## 刷新时,关闭安全验证
management.security.enabled=false

spring.application.name=config-client
spring.cloud.config.label=master
spring.cloud.config.profile=test
spring.cloud.config.uri= http://localhost:9000/

##注册中心地址
eureka.client.service-url.defaultZone=http://eureka.dalaoyang.cn/eureka/

启动类加入注解@RefreshScope,代码如下:

package com.dalaoyang;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
@RefreshScope
public class SpringcloudBusApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringcloudBusApplication.class, args);
    }


    @Value("${title}")
    String title;

    @RequestMapping("/getTitle")
    public String getTitle(){
        return title;
    }
}

config-client加入同样依赖和配置,重启config-client,启动springcloud_bus,先去http://eureka.dalaoyang.cn/,可以看到

9953332-8dbb23361cc4919a
image

先将git上配置改回dalaoyang_test,分别请求http://localhost:8881/getTitlehttp://localhost:8080/getTitle结果如下:

9953332-ff6e22df4b77f19e
image
9953332-9f9a574dc861675a
image

然后用postman使用post请求访问http://localhost:8881/bus/refresh

再次分别请求http://localhost:8881/getTitlehttp://localhost:8080/getTitle结果如下:

9953332-e41c96398b690176
image
9953332-3c87773d68c5e693
image

从图中可以看出刷新配置成功。

3.局部刷新配置,配置与第2种方法一样,只是在使用postman刷新时略加改变,在本文中使用http://localhost:8881/bus/refresh?destination=config-client:8881可以刷新服务名为config-client端口为8881的服务,如果想要刷新服务名为config-client的所有服务可以写成http://localhost:8881/bus/refresh?destination=config-client:**

源码下载 :大老杨码云

个人网站:https://www.dalaoyang.cn

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