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SpringCloud成长笔记(一)服务注册与发现(Eureka)一、SpringCloud简介二、环境搭建三、代码四、运行五、代码六、参考资料

一、SpringCloud简介

springCloud是在springboot的基础上形成的组件库,本章我们先介绍Eureka([juˈri:kə])

二、环境搭建

springboot版本2.1.0.RELEASE,springcloud版本Greenwich.M1

新建工程

SpringCloud成长笔记(一)服务注册与发现(Eureka)一、SpringCloud简介二、环境搭建三、代码四、运行五、代码六、参考资料

工程名

SpringCloud成长笔记(一)服务注册与发现(Eureka)一、SpringCloud简介二、环境搭建三、代码四、运行五、代码六、参考资料

spring生态体系的组件

SpringCloud成长笔记(一)服务注册与发现(Eureka)一、SpringCloud简介二、环境搭建三、代码四、运行五、代码六、参考资料
SpringCloud成长笔记(一)服务注册与发现(Eureka)一、SpringCloud简介二、环境搭建三、代码四、运行五、代码六、参考资料

我们选中Cloud Bootstrap,eureka server,eureka discovery

创建两个module,其他没用的文件都删除,基本框架如下

SpringCloud成长笔记(一)服务注册与发现(Eureka)一、SpringCloud简介二、环境搭建三、代码四、运行五、代码六、参考资料

三、代码

服务端:

pom.xml

<?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.mhm</groupId>
	<artifactId>server</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>server</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.1.0.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>Greenwich.M1</spring-cloud.version>
	</properties>

	<dependencies>
		<!--springcloud 版本-->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter</artifactId>
		</dependency>

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

		<!--eureka 20181114-->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-eureka</artifactId>
			<version>1.4.0.RELEASE</version>
		</dependency>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-config-server</artifactId>
			<version>1.4.3.RELEASE</version>
		</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>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>


</project>

           

application.properties,不管用yml还是properties,习惯了用properties了。

package com.mhm;

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

@SpringBootApplication
@EnableEurekaServer
public class ServerApplication {

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

           

增加@EnableEurekaServer的注解,如果依赖没有,maven–>Reimport一次,运行。

SpringCloud成长笔记(一)服务注册与发现(Eureka)一、SpringCloud简介二、环境搭建三、代码四、运行五、代码六、参考资料

这时候还没有客户端注册上来。

客户端:

pom.xml

<?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.mhm</groupId>
	<artifactId>client</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>client</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.1.0.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>Greenwich.M1</spring-cloud.version>
	</properties>

	<dependencies>
		<!--springcloud 版本-->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter</artifactId>
		</dependency>

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

		<!--eureka 20181114-->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-eureka</artifactId>
			<version>1.4.0.RELEASE</version>
		</dependency>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-config-server</artifactId>
			<version>1.4.3.RELEASE</version>
		</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>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>


</project>

           

application.properties

server.port=8080
spring.application.name=eureka-client
eureka.client.service-url.defaultZone=http://localhost:8080/eureka
           

代码:

package com.mhm;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class ClientApplication {

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

           

只需要增加@EnableDiscoveryClient的注解即可。

四、运行

SpringCloud成长笔记(一)服务注册与发现(Eureka)一、SpringCloud简介二、环境搭建三、代码四、运行五、代码六、参考资料

服务端可以看到客户端注册上来

SpringCloud成长笔记(一)服务注册与发现(Eureka)一、SpringCloud简介二、环境搭建三、代码四、运行五、代码六、参考资料
SpringCloud成长笔记(一)服务注册与发现(Eureka)一、SpringCloud简介二、环境搭建三、代码四、运行五、代码六、参考资料

上面看到了是两个客户端注册了上来,是因为客户端重启了一次。

EMERGENCY! EUREKA MAY BE INCORRECTLY CLAIMING INSTANCES ARE UP WHEN THEY’RE NOT. RENEWALS ARE LESSER**

红色部分:

保护模式,客户端即使停止了,服务器端也会记录下来。。

增加如下的配置,则会剔除停止的节点,60秒监测一次,剔除停止的节点

eureka.server.enable-self-preservation=false

eureka.server.eviction-interval-timer-in-ms=60000

客户端的配置

eureka.client.healthcheck.enabled # 开启健康检查(需要spring-boot-starter-actuator依赖)

eureka.instance.lease-renewal-interval-in-seconds # 续约更新时间间隔(默认30秒)

eureka.instance.lease-expiration-duration-in-seconds # 续约到期时间(默认90秒)

启动服务端:

THE SELF PRESERVATION MODE IS TURNED OFF. THIS MAY NOT PROTECT INSTANCE EXPIRY IN CASE OF NETWORK/OTHER PROBLEMS.

自我保存模式关闭。在网络/其他问题的情况下,这可能无法保护实例失效

客户端掉线后,服务端剔除断掉的节点

五、代码

Github

六、参考资料

官网资料

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