一、简介
Spring cloud Eureka是spring Cloud Netflix微服务套件中的一部分,它基于Netflix Eureka做了二次封装,主要负责完成微服务架构中的服务治理功能。Spring Cloud通过为Eureka增加了Spring Boot 风格的自动化配置,我们只需要通过简单的引入依赖和注解配置就能让Spring Boot构建的微服务应用轻松地与Eureka服务治理体系进行整合。
二、搭建服务注册中心:
1、首先创建一个基础的Spring boot工程,命名为 eureka-server,并在pom中引入必要内容:
<?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.anzy</groupId>
<artifactId>eureka-server</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>eureka-server</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.0.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>
</properties>
<dependencies>
<!--增加eureka-server的依赖-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka-server</artifactId>
</dependency>
<!--用于测试的,本例可省略-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<!--依赖管理,用于管理spring-cloud的依赖,其中Camden.SR3是版本号-->
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Camden.SR3</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、通过
@EnableEurekaServer 注解启动一个服务注册中心供给其他应用进行对话。
package com.anzy.eurekaserver;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@EnableEurekaServer
@SpringBootApplication
public class EurekaServerApplication {
public static void main(String[] args) {
// SpringApplication.run(EurekaServerApplication.class, args);
new SpringApplicationBuilder(EurekaServerApplication.class).web(true).run(args);
}
}
3、在默认配置下,该服务注册中心会将自己作为客户端来尝试注册他自己,所以我们需要在application.properties中增加相关配置:
server.port=1111
eureka.instance.hostname=localhost
# 由于应用为注册中心,所以设置为false,代表不想注册中心注册自己
eureka.client.register-with-eureka=false
#由于注册中心的职责就是维护服务实例,他不需要去检索服务,所以设置为false
eureka.client.fetch-registry=false
eureka.client.serviceUrl.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka/
4、完成上述操作启动项目访问 http://localhost:1111,可看到如下信息
可看到Instances currently registered with Eureka
栏下没有注册任何服务。
注:如果启动报错可能原因是引入的jar版本有冲突,可修改一下版本号。
三、注册服务提供者
1、创建一个基础的Spring boot项目,创建项目名为demo,修改pom:
<?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.anzy</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.0.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>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<!--增加eureka-server的依赖-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
</dependencies>
<!--依赖管理,用于管理spring-cloud的依赖,其中Camden.SR3是版本号-->
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Camden.SR3</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、创建controller,添加DiscoverClient
package com.anzy.demo.test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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.GetMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* Created by anzy on 2018/4/21.
*/
@RestController
public class HelloController {
private final Logger logger = LoggerFactory.getLogger(HelloController.class);
@Autowired
private DiscoveryClient discoveryClient;
@GetMapping("hello")
public String hello(){
ServiceInstance instance = discoveryClient.getLocalServiceInstance();
logger.info("/hello,host:" + instance.getHost() + ",service_id:"+instance.getServiceId());
return "hello spring boot";
}
}
3、在主类(启动类)里面添加@EnableEurekaClient
package com.anzy.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
@EnableEurekaClient
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
4、修改配置文件application.properties
spring.application.name=demo
eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka
5、启动项目,刷新http://localhost:1111,可看到demo已经注册到上面。
简单的单机服务治理就此搭建好。
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服务治理界面上那句红字具体怎么回事我暂时还没研究,有知道的可以简单说一下,供大家学习。
可加Q群551807041 一起学习。