SpringCloud微服务实战之服务治理Eureka(单节点)

╰半夏微凉° 2022-06-02 20:27 210阅读 0赞

> Euraka是NetFlix微服务套件中的一部分，它基于Netflix Eureka做了二次封装，主要负责完成微服务架构中的服务治理和服务发现功能。

## 示例： ##

**一、Eureka搭建服务注册**  
1、创建maven项目SpringCloud-EurekaServer  
![这里写图片描述][SouthEast]  
2、修改pom.xml文件，pom中添加Euraka依赖jar包。

<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.spring</groupId>
      <artifactId>SpringCloud-EurekaServer</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <packaging>jar</packaging>
    
      <name>SpringCloud-EurekaServer</name>
      <url>http://maven.apache.org</url>
    
      <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
      </properties>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.3.5.RELEASE</version>
            <relativePath/> 
        </parent>
    
        <dependencies>
            <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-eureka-server</artifactId>
            </dependency>
        </dependencies>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Brixton.RELEASE</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>

3、创建application.propertises文件

server.port=8888
    
    eureka.client.register-with-eureka=false
    eureka.client.fetch-registry=false
    eureka.client.serviceUrl.defaultZone=http://localhost:${server.port}/eureka/

*  server.port：Eureka服务注册端口。
 *  eureka.client.register-with-eureka：设置为false，代表不向注册中心注册自己。
 *  eureka.client.fetch-registry：设置为false，代表不去检索服务。
    
    通过[http://localhost:8888/][http_localhost_8888]访问注册中心：  
    ![这里写图片描述][SouthEast 1]
    
    由于该注册中心还没注册任何服务，所以Instances currently registered with Eureka栏为“No instances available”。

**二、在服务注册中心注册helloService服务**

1、创建Maven项目SpringCloud-Service  
![这里写图片描述][SouthEast 2]

2、修改pom.xml，添加Euraka和SpringBoot依赖

<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.spring</groupId>
      <artifactId>SpringCloud-Service</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <packaging>jar</packaging>
    
      <name>SpringCloud-Service</name>
      <url>http://maven.apache.org</url>
    
      <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
      </properties>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.3.5.RELEASE</version>
            <relativePath/> 
        </parent>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</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-eureka-server</artifactId>
            </dependency>
        </dependencies>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Brixton.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            </dependencies>
        </dependencyManagement>
    </project>

3、新增application.propertises文件

server.port=9999
    
    spring.application.name=helloService
    eureka.client.serviceUrl.defaultZone=http://localhost:8888/eureka/

*  server.port：helloService服务端口。
 *  spring.application.name：向服务注册中心注册的服务名。
 *  eureka.client.serviceUrl.defaultZone：eureka服务注册中心Url。

4、实现HelloServiceController

package com.spring.springcloud.rest;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.cloud.client.ServiceInstance;
    import org.springframework.cloud.client.discovery.DiscoveryClient;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class HelloServiceController {
    
        @Autowired
        private DiscoveryClient client;
    
        @RequestMapping(value="/hello",method=RequestMethod.GET)
        public String greeting(){
    
            ServiceInstance si = client.getLocalServiceInstance();
    
            return "hello";
        }
    }

5、最后向Application主类中添加注解@EnableDiscoveryClient，用于激活Eureka中的EnableDiscoveryClient实现。

package com.spring.springcloud;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    
    @EnableDiscoveryClient
    @SpringBootApplication
    public class Application {
    
        public static void main(String[] args) {
            SpringApplication.run(Application.class, args);
        }
    
    }

运行HelloService注册服务，启动成功之后，访问注册中心：[http://localhost:8888/][http_localhost_8888]

![这里写图片描述][SouthEast 3]

此时我们看见helloService已经成功注册。

[SouthEast]: /images/20220603/d4daeb66d4b34e0b80991f253a0533d0.png
[http_localhost_8888]: http://localhost:8888/
[SouthEast 1]: /images/20220603/ad60256f07e44073aafbc6554809fe44.png
[SouthEast 2]: /images/20220603/e16cdca268314866909ad415568cc8ae.png
[SouthEast 3]: /images/20220603/973f0f8048c4461ebabd88546de1cc42.png