Spring Cloud(Finchley.RCI) (二) Spring Cloud服務註冊與發現

在這裏, 我們需要的組件是Spring Cloud Netflix的Eureka, Eureka是一個服務註冊與發現模塊

創建服務註冊中心

pom文件

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.funtl</groupId>
        <artifactId>hello-spring-cloud-dependencies</artifactId>
        <version>1.0.0-SNAPSHOT</version>
        <relativePath>../hello-spring-cloud-dependencies/pom.xml</relativePath>
    </parent>

    <artifactId>hello-spring-cloud-eureka</artifactId>
    <packaging>jar</packaging>

    <name>hello-spring-cloud-eureka</name>
    <url>http://www.funtl.com</url>
    <inceptionYear>2018-Now</inceptionYear>

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

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

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <mainClass>com.funtl.hello.spring.cloud.eureka.EurekaApplication</mainClass>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

Application

啓動一個服務註冊中心, 只需要一個註解@EnableEurekaServer

package com.funtl.hello.spring.cloud.eureka;

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

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

application.yml

Eureka是一個高可用的組件, 它沒有後端緩存, 每一個實例註冊之後需要向註冊中心發送心跳(因此可以在內存中完成), 在默認情況下Eureka Server也是一個Eureka Client必須要指定一個Server.

spring:
  application:
    name: hello-spring-cloud-eureka

server:
  port: 5761

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