Spring Cloud Eureka 实现

Dear 丶 2022-03-15 09:16 251阅读 0赞

之前项目中用到了spring cloud的一些服务，这里准备将spring cloud最常用的一些服务框架进行总结和实现。

框架大致的介绍在之前的文章里面已经有提及：[什么是微服务][Link 1]

这里就从springcloud最开始搭建说起，也就是服务发现和注册，原生提供的就是Eureka服务端和客户端，之后由于zookeeper的流行，也提供你spring cloud zookeeper的实现方式，本文主要还是提供了eureka的实现方法。

eureka 包含client端和server端，主要是做微服务的服务发现功能。

下面开始具体执行顺序。我这边用的是intellJ IDEA开发的

1.server服务端配置：

我这边用的idea 带的spring init工具直接快速构建，如果没有的话也可以通过[https://start.spring.io][https_start.spring.io] 页面进行构建

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 2][]

对应生成的pom.xml内容是：

<?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>2.1.3.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.cloud</groupId>
        <artifactId>server</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>server</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
            <spring-cloud.version>Greenwich.RELEASE</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.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>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
        <repositories>
            <repository>
                <id>spring-milestones</id>
                <name>Spring Milestones</name>
                <url>https://repo.spring.io/milestone</url>
            </repository>
        </repositories>
    
    </project>

2.启动类

在启动类ServerApplication上加上@EnableEurekaServer

@SpringBootApplication
    @EnableEurekaServer
    public class ServerApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(ServerApplication.class, args);
        }
    
    }

在application.properties配置文件里面加上端口号，和一些配置字段

server.port = 12345
    spring.application.name = config-center
    
    eureka.instance.hostname:localhost
    #该应用为注册中心，不向自己注册自己
    eureka.client.register-with-eureka=false
    #是否从euruka服务器获取注册信息
    eureka.client.fetch-registry=false
    eureka.client.service-url.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka/
    
    logging.level.com.netflix.eureka:OFF
    logging.level.com.netflix.discovery:OFF

然后启动 ServerApplication

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 3][]

我这边配置的端口号是12345，启动成功之后再浏览器中输入 [http://localhost:12345/][http_localhost_12345] 可以进入euraka配置管理界面，因为目前还没有服务注册到这个服务管理端，所以applications里面显示的是No instances available

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 4][]

##  2.配置微服务客户端 ##

接下来就是配置各微服务的客户端并将这些服务注册到服务端上进行统一管理。

依旧是使用spring init工具，这里的微服务我这边加入了数据库的支持。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 5][]

对应的pom.xml文件是：

<?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>2.1.3.RELEASE</version>
    		<relativePath/> 
    	</parent>
    	<groupId>com.cloud</groupId>
    	<artifactId>client</artifactId>
    	<version>0.0.1-SNAPSHOT</version>
    	<name>client</name>
    	<description>Demo project for Spring Boot</description>
    
    	<properties>
    		<java.version>1.8</java.version>
    		<spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
    	</properties>
    
    	<dependencies>
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-data-jpa</artifactId>
    		</dependency>
    		<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.cloud</groupId>
    			<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    		</dependency>
    
    		<dependency>
    			<groupId>mysql</groupId>
    			<artifactId>mysql-connector-java</artifactId>
    			<scope>runtime</scope>
    		</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>
    
    	<repositories>
    		<repository>
    			<id>spring-milestones</id>
    			<name>Spring Milestones</name>
    			<url>https://repo.spring.io/milestone</url>
    		</repository>
    	</repositories>
    
    </project>

然后再启动类ClientApplication上加上@EnableEurekaClient 或者@EnableDiscoveryClient，这里建议使用@EnableDiscoveryClient，因为如果用zookeeper的方式也用@EnableDiscoveryClient就可以了。

然后是配置文件中需要添加的内容：

server.port = 10000
    
    eureka.client.serviceUrl.defaultZone= http://localhost:12345/eureka/
    spring.application.name= spring-client-01

一个是服务端口号，一个是服务端地址，再就是自己服务名称。

然后启动 这个服务。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 6][]

启动完成之后，浏览器进入服务管理端，[http://localhost:12345/][http_localhost_12345]

可以看到新增的服务已经注册进来了。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 7][]

github源码地址：源码地址

[Link 1]: https://blog.csdn.net/harryptter/article/details/82875212
[https_start.spring.io]: https://start.spring.io
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70]: /images/20220315/68c60bab47bf417888454bb78803ed1d.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 1]: /images/20220315/304feaa30ed64c8fbebb4610280ab86c.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 2]: /images/20220315/1bb7e05634dd4fb0b73d3a48f1430215.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 3]: /images/20220315/6a13de838f9243a2867b7a48576de228.png
[http_localhost_12345]: http://localhost:12345/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 4]: /images/20220315/e68ec85ab2734543a3796016dc68d8bf.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 5]: /images/20220315/fc9b749a79f24da3850f02bb01799312.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 6]: /images/20220315/b6cc1a60ba2d4c29a2815818e71826ee.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hhcnJ5cHR0ZXI_size_16_color_FFFFFF_t_70 7]: /images/20220315/7b4f245d83b64622b79c78be0d76efd7.png