先说Eureka的原理,Eureka是一个强调高可用性的服务注册与发现组件,它带有心跳、数据增量同步、互相复制、缓存信息等特有机制。
Eureka分为客户端和服务端,客户端即我们之前写的服务消费者和提供者,服务端就是Eureka将客户端的信息注册到服务机,实现服务的发现和注册
心跳机制:微服务启动后,定期向EurekaServer发送心跳,如果某段时间没有收到微服务发送的心跳就会注销该微服务,默认时间为90秒
缓存信息:当面对高并发的请求时,就会对服务器造成压力,Eureka可以通过缓存注册信息的方式减缓压力
互相复制:默认下,EurekaServer同时也是EurekaClient,因此可以相互复制,以实现数据的同步
新建一个EurekaServer工程,搜索Eureka勾选server
在启动类中添加@EnableEurekaServer注解
package com.lyl.cloud;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@SpringBootApplication
@EnableEurekaServer
public class EurekaServerApplication {
public static void main(String[] args) {
SpringApplication.run(EurekaServerApplication.class, args);
}
}
然后对配置文件进行配置
application.properties
#设置服务器的端口
server.port=8761
#Eureka配置
#是否将自己注册到Eureka-server上
eureka.client.register-with-eureka=true
#是否从其他的Eureka-server获取注册信息,
eureka.client.fetch-registry=true
#设置与EurekaSever交互的地址,查询和注册服务都需要以来这个地址,多个地址可以用","逗号进行分隔
eureka.client.service-url.defaultZone=http://localhost:8761/eureka/
启动项目并在浏览器输入:http://localhost:8761/
可以访问到这个页面,接下来我们把之前写的服务注册到Eureka-Server中
打开provider-user,打开pom文件,在里面加上eureka的依赖,注:如果出现冲突问题,尝试去掉<version>或者改变版本
<?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>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.2.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>com.lyl.cloud</groupId>
<artifactId>provider-user</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>provider-user</name>
<description>Demo project for Spring Boot</description>
<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>Finchley.BUILD-SNAPSHOT</spring-cloud.version>
</properties>
<!-- web、mybatis与mysql的依赖文件 -->
<dependencies>
<!-- eureka依赖 -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- 监控,以了解程序运行情况 通过http://ip:端口/health进行访问查询,通过http://ip:端口/info进行查询项目配置
查询info的配置在properties文件中进行详细配置,要显示的信息 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
</dependencies>
<!-- springcloud的依赖 -->
<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-snapshots</id>
<name>Spring Snapshots</name>
<url>https://repo.spring.io/snapshot</url>
<snapshots>
<enabled>true</enabled>
</snapshots>
</repository>
<repository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-snapshots</id>
<name>Spring Snapshots</name>
<url>https://repo.spring.io/snapshot</url>
<snapshots>
<enabled>true</enabled>
</snapshots>
</pluginRepository>
<pluginRepository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
</pluginRepository>
</pluginRepositories>
</project>
然后对application.properties进行相关的配置
#mybatis扫描路径
mybatis.type-aliases-package=com.lyl.cloud.entity
#mysql连接配置
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/cloud?useUnicode=true&characterEncoding=UTF-8&useSSL=false
spring.datasource.username=root
spring.datasource.password=root
#springMVC配置
spring.mvc.view.prefix=classpath:/templates/*
#配置端口
server.port=8000
#项目配置说明,通过http://ip(localhost):端口(8000)/info进行查询
[email protected]@
info.app.encoding:@project.build.sourceEncoding@
info.app.java.source:@java.version@
info.app.java.target:@java.version@
#整合eureka
#注册到server的应用名称
spring.application.name=provider-user
#注册地址
eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/
#是否将自己的ip注册到server,如果不设置或者设为false那就将操作系统的hostname注册到server
eureka.instance.prefer-ip-address=true
最后在启动类上加上@EnableDiscoveryClient注解即可
package com.lyl.cloud;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
/**
* @EnableDiscoveryClient声明这是一个EurekaClient
* @MapperScan对括号里面的路径进行扫描
* @author canbe
*
*/
@EnableDiscoveryClient
@SpringBootApplication
@MapperScan("com.lyl.cloud.mapper.*")
public class ProviderUserApplication {
public static void main(String[] args) {
SpringApplication.run(ProviderUserApplication.class, args);
}
}
同样的操作我们在provider-consumer中再进行一遍,最后进行测试,先打开server
再打开provider-user和provider-consumer
发现服务已经注册到server上了,下一节我们说服务发现