springcloud-eureka简单实现

请参考 spring+cloud为服务实战 第三章

一。创建Eureka服务

1.使用Idea创建一个项目

结构如下：

2.pom.xml配置:

<?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.cloudlearn</groupId>
	<artifactId>core</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>core</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.6.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>
		<spring-cloud.version>Finchley.SR1</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>
		</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.启动类配置

/*通过@EnableEurekaServer注解启动一个服务注册中心，提供给其他应用进行对话
 * 默认情况下服务注册中心也会将自己作为客户端尝试注册自己，所以我们应该禁止，只需在配置文件中修改即可（application.properties有详细说明）:
 * eureka.client.register-with-eureka=false
 * eureka.client.fetch-registry=false
 * */
@EnableEurekaServer
@SpringBootApplication
public class CoreApplication {

	public static void main(String[] args) {
		SpringApplication.run(CoreApplication.class, args);
	}
}

　4.application.properties配置

server.port=1111

eureka.instance.hostname=localhost
#由于该应用未注册中心，所以设置为false,代表不向注册中心注册自己
eureka.client.register-with-eureka=false
#由于注册中心的职责就是维护实例，所以它并不需要去检索服务，所以设置成false
eureka.client.fetch-registry=false
eureka.client.service-url.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka

5.运行一下我们的项目 并且访问  http://localhost:1111/ 结果如下：

因为以上只是开启了服务注册中心，所以还没有服务，下面我们在创建一个注册服务

二。注册服务

1.创建过程与上面类似只是选择服务那里有些许不同（web项目）

2.pom.xml配置：

<?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.cloudlearn</groupId>
	<artifactId>zhuce</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>zhuce</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.6.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>
		<spring-cloud.version>Finchley.SR1</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.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>
		</dependency>
		<!-- https://mvnrepository.com/artifact/log4j/log4j -->
		<dependency>
			<groupId>log4j</groupId>
			<artifactId>log4j</artifactId>
			<version>1.2.17</version>
		</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.启动类配置

@RestController
public class HelloController {
    private final static org.apache.log4j.Logger log = org.apache.log4j.Logger.getLogger(HelloController.class);
    @Autowired
    private DiscoveryClient discoveryClient;

    @RequestMapping("/hello")
    public String Hello(){
        discoveryClient.getServices().forEach(id -> {
            discoveryClient.getInstances(id).forEach(instance -> {
                log.info("/hello, host:" + instance.getHost() + ", service_id:" + instance.getServiceId());
            });
        });
        return "Hello World";
    }
}

　　

//通过添加注解EnableDiscoveryClient，激活Eureka中的DiscoveryClient实现（自动化配置，创建DiscoveryClient接口针对Eureka客户端的EurekaDiscoveryClient实例）

@EnableDiscoveryClient
@SpringBootApplication
public class ZhuceApplication {

	public static void main(String[] args) {
		SpringApplication.run(ZhuceApplication.class, args);
	}
}

　　

4.application.properties配置：

#服务的名称
spring.application.name=hello-service
#指定服务中心的地址（我们上一个服务中心的地址）
eureka.client.service-url.defaultZone=http://localhost:1111/eureka/

　　

5.启动我们的项目，结果如下代表启动成功

　　然后在运行  http://localhost:1111/ 结果如下：

运行http://localhost:8080/hello，结果控制台日志打印：