spring服务注册和发现的实现springCloudStarterNetflixEurekaServer

1.spring服务注册和发现

2.编译条件

• JDK 1.8 or later

• Gradle 4+ or Maven 3.2+

3.代码格式

3.1 service目录

3.2 client的目录

4.POM.xml的文件

   4.0.0
   
      org.springframework.boot
      spring-boot-starter-parent
      2.2.2.RELEASE
       
   
   com.example
   service-registration-and-discovery-service
   0.0.1-SNAPSHOT
   service-registration-and-discovery-service
   Demo project for Spring Boot

   
      1.8
      Hoxton.SR1
   

   
      
         org.springframework.cloud
         spring-cloud-starter-netflix-eureka-server
      

      
         org.springframework.boot
         spring-boot-starter-test
         test
         
            
               org.junit.vintage
               junit-vintage-engine
            
         
      
   

   
      
         
            org.springframework.cloud
            spring-cloud-dependencies
            ${spring-cloud.version}
            pom
            import
         
      
   

   
      
         
            org.springframework.boot
            spring-boot-maven-plugin
         
      
   

   
      
         spring-milestones
         Spring Milestones
         https://repo.spring.io/milestone
      
   

build.gradle

plugins {
   id 'org.springframework.boot' version '2.2.2.RELEASE'
   id 'io.spring.dependency-management' version '1.0.8.RELEASE'
   id 'java'
}

group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '1.8'

repositories {
   mavenCentral()
   maven { url 'https://repo.spring.io/milestone' }
}

ext {
   set('springCloudVersion', "Hoxton.SR1")
}

dependencies {
   implementation 'org.springframework.cloud:spring-cloud-starter-netflix-eureka-server'
   testImplementation('org.springframework.boot:spring-boot-starter-test') {
      exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
   }
}

dependencyManagement {
   imports {
      mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
   }
}

test {
   useJUnitPlatform()
}

5.原理

 

启动Eureka服务注册表
您首先需要一个Eureka服务注册中心。

可以使用Spring Cloud的@EnableEurekaServer来建立一个注册表，其他应用程序可以与之通信。

这是一个常规的Spring引导应用程序，添加了一个注释（@enableeruekaserver）以启用服务注册表

 

5.1 启动EurekaServer的服务

@EnableEurekaServer
@SpringBootApplication

package com.example.serviceregistrationanddiscoveryservice;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@EnableEurekaServer
@SpringBootApplication
public class ServiceRegistrationAndDiscoveryServiceApplication {

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

5.2 启动Client的客户端

@EnableDiscoveryClient
@SpringBootApplication

定义一个Client的客服端

package com.example.serviceregistrationanddiscoveryclient;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@EnableDiscoveryClient
@SpringBootApplication
public class ServiceRegistrationAndDiscoveryClientApplication {

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

@RestController
class ServiceInstanceRestController {

   @Autowired
   private DiscoveryClient discoveryClient;

   @RequestMapping("/service-instances/{applicationName}")
   public List serviceInstancesByApplicationName(
         @PathVariable String applicationName) {
      return this.discoveryClient.getInstances(applicationName);
   }
}

5.3配置为

server.port=8761

eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false

logging.level.com.netflix.eureka=OFF
logging.level.com.netflix.discovery=OFF

5.4 测试应用程序

 

5.4.1 要使用Maven运行Eureka服务，请在终端窗口（在/complete目录中）中运行以下命令：

./mvnw spring-boot:run -pl eureka-service

下载老半天，不好用，修改为, 本机也配置了mvn环境，

mvn spring-boot:run -pl eureka-service

编译成功后，启动界面为：启动服务端口为8761端口，

2020-04-06 19:42:12.075  INFO 4075 --- [      Thread-11] o.s.c.n.e.server.EurekaServerBootstrap   : Initialized server context
2020-04-06 19:42:12.100  INFO 4075 --- [      Thread-11] e.s.EurekaServerInitializerConfiguration : Started Eureka Server
2020-04-06 19:42:12.139  INFO 4075 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8761 (http) with context path ''
2020-04-06 19:42:12.140  INFO 4075 --- [           main] .s.c.n.e.s.EurekaAutoServiceRegistration : Updating port to 8761
2020-04-06 19:42:12.144  INFO 4075 --- [           main] gistrationAndDiscoveryServiceApplication : Started ServiceRegistrationAndDiscoveryServiceApplication in 19.956 seconds (JVM running for 20.472)
 

进入界面为：

5.4.2要使用Maven运行Eureka客户机，请在终端窗口（在/complete目录中）中运行以下命令：

./mvnw spring-boot:run -pl eureka-client

打开终端，点击下面加号，新的session,运行eureka-client

输入下面命令mvn spring-boot:run -pl eureka-client

要使用Gradle运行Eureka服务，请在终端窗口（在/complete目录中）中运行以下命令：

./gradlew :eureka-service:bootRun

要使用Gradle运行Eureka客户机，请在终端窗口（在/complete目录中）中运行以下命令：

./gradlew :eureka-client:bootRun