服务注册与发现

本节视频

概述

在这里,我们需要用的组件是 Spring Cloud Netflix 的 Eureka,Eureka 是一个服务注册和发现模块

创建服务注册中心

pom.xml 文件配置如下:

<?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>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>
        <!-- Spring Boot Begin -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- Spring Boot End -->

        <!-- Spring Cloud Begin -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
        <!-- Spring Cloud End -->
    </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>
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Application

启动一个服务注册中心,只需要一个注解 @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);
    }
}
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application.yml

Eureka 是一个高可用的组件,它没有后端缓存,每一个实例注册之后需要向注册中心发送心跳(因此可以在内存中完成),在默认情况下 Erureka Server 也是一个 Eureka Client ,必须要指定一个 Server。

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

server:
  port: 8761

eureka:
  instance:
    hostname: localhost
  client:
    registerWithEureka: false
    fetchRegistry: false
    serviceUrl:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
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通过 eureka.client.registerWithEureka:falsefetchRegistry:false 来表明自己是一个 Eureka Server.

操作界面

Eureka Server 是有界面的,启动工程,打开浏览器访问:

http://localhost:8761

上次更新: 2019-4-19 19:23:15