1、Eureka介紹
Eureka架構中的三個核心角色:
- 服務註冊中心
Eureka的服務端應用,提供服務註冊和發現功能(eureka-server) - 服務提供者
提供服務的應用,可以是SpringBoot應用,也可以是其它任意技術實現,只要對外提供的是Rest風格服務即可。(user-service) - 服務消費者
消費應用從註冊中心獲取服務列表,從而得知每個服務方的信息,知道去哪裏調用服務方。(user-client)
2、基礎環境搭建
創建一個maven工程
工程結構
2.1 eureka server 模塊 Eureka註冊中心
引入的依賴
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 https://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>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.boss</groupId>
<artifactId>eureka-server</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>eureka-server</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Hoxton.RELEASE</spring-cloud.version>
</properties>
<dependencies>
<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-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2.2 user-service (服務提供者)引入的依賴
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.boss</groupId>
<artifactId>user-service</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>user-service</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Hoxton.RELEASE</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${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>
</project>
2.3 user-client (服務消費者)引入的依賴
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 https://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>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.boss</groupId>
<artifactId>user-client</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>user-client</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Hoxton.RELEASE</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
3、配置註冊中心
3.1 聲明這個應用是一個EurekaServer(註冊中心)
3.2 編寫配置文件
application.yml
server:
port: 8761 # 端口
spring:
application:
name: eureka-server # 應用名稱,會在Eureka中顯示
freemarker:
prefer-file-system-access: false
eureka:
client:
register-with-eureka: false # 是否註冊自己的信息到EurekaServer,默認是true
fetch-registry: false # 是否拉取其它服務的信息,默認是true
service-url: # EurekaServer的地址,現在是自己的地址,如果是集羣,需要加上其它Server的地址。
defaultZone: http://127.0.0.1:${server.port}/eureka
3.3 啓動Eureka Server
4、服務提供者
user-service 對外提供接口服務,可以通過訪問http://localhost:8088/hello 來獲取用戶數據
在服務上添加Eureka的客戶端依賴,客戶端代碼會自動把服務註冊到Eureka Server中。
4.1 啓動類上開啓Eureka客戶端功能
通過添加@EnableDiscoveryClient
來開啓Eureka客戶端功能
4.2 配置
application.yml
server:
port: 8088
spring:
application:
name: user-service # 應用名稱
eureka:
client:
service-url: # EurekaServer地址
defaultZone: http://127.0.0.1:8761/eureka
instance:
prefer-ip-address: true # 當其它服務獲取地址時提供ip而不是hostname
ip-address: 127.0.0.1 # 指定自己的ip信息,不指定的話會自己尋找
4.3 編寫代碼
4.4 測試
訪問實際接口
查看註冊中心,可以發現我們的服務已經註冊上去了
5、服務消費者
user-client 通過註冊中心獲取數據接口,處理後返回給用戶
在服務上添加Eureka的客戶端依賴,客戶端代碼會自動把服務註冊到Eureka Server中。
5.1 啓動類上開啓Eureka客戶端功能
5.2 配置
application.yml
server:
port: 8089
spring:
application:
name: user-client # 應用名稱
eureka:
client:
service-url: # EurekaServer地址
defaultZone: http://127.0.0.1:8761/eureka
instance:
prefer-ip-address: true # 當其它服務獲取地址時提供ip而不是hostname
ip-address: 127.0.0.1 # 指定自己的ip信息,不指定的話會自己尋找
5.3 編寫接口訪問代碼
package com.boss.userclient.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
/**
* @author LGX_TvT
* @date 2019-12-03 16:24
*/
@RestController
public class HelloController {
@Autowired
private RestTemplate restTemplate;
@Autowired
private DiscoveryClient discoveryClient;// Eureka客戶端,可以獲取到服務實例信息
@RequestMapping("/hello")
public String doClientHello(){
// 根據服務名稱,獲取服務實例,因爲只有一個UserService,因此我們直接get(0)獲取
ServiceInstance serviceInstance = discoveryClient.getInstances("user-service").get(0);
// 獲取ip和端口信息,拼接url
String baseURL = "http://" + serviceInstance.getHost() + ":" + serviceInstance.getPort() + "/hello";
String msg = restTemplate.getForObject(baseURL, String.class);
return msg + "!!!";
}
}
5.4 測試
啓動服務消費方,查看註冊中心
可以看到客戶端已經註冊成功
訪問鏈接