创建服务注册中心

创建一个基于Spring boot 2.x的工程，命名为eureka-server，相比spring boot1
.x系列，eureka-server的依赖有变化，spring-cloud的版本也需要修改成Finchley.RC1版本，pom.xml如下：

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.1.RELEASE</version>
    <relativePath/>
</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</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-config</artifactId>
    </dependency>
</dependencies>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Finchley.RC1</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

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

@EnableEurekaServer
@SpringBootApplication
public class EurekaServerApplication {
    public static void main(String[] args) {
        SpringApplication.run(EurekaServerApplication.class, args);
    }
}

并在application.yml配置文件中增加如下信息：

spring:
  application:
    name: eureka-server
server:
  port: 1001
eureka:
  instance:
    hostname: localhost
  client:
    register-with-eureka: false
    fetch-registry: false

启动工程后，访问：http://localhost:1001/，可以看到下面的页面，其中还没有任何服务

1.png

创建服务注册发现端

创建一个新的springboot工程，命名为eureka-client，作为提供服务的客户端，并向服务注册中心注册自己，pom.xml如下

<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</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>
</dependencies>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Finchley.RC1</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

并实现一个接口,通过DiscoveryClient对象打印客户端名称和端口：

@RestController
public class TestController {
    @Autowired
    private DiscoveryClient discoveryClient;

    @Value("${server.port}")
    private String port;

    @GetMapping("/disc")
    public String dc() {
        return "Services: " + discoveryClient.getServices() + ":" + port;
    }
}

启动类这里通过@EnableDiscoveryClient进行注解启动一个服务提供端，并激活DiscoveryClient

@EnableDiscoveryClient
@SpringBootApplication
public class EurekaClientApplication {

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

application.yml需要配置注册中心地址和服务名称：

spring:
  application:
    name: eureka-client
server:
  port: 2001
eureka:
  instance:
    hostname: localhost
    prefer-ip-address: true
    instance-id: ${eureka.instance.hostname}:${spring.application.name}:${server.port}
  client:
    serviceUrl:
      defaultZone: http://localhost:1001/eureka/ 

启动工程，刷新 http://localhost:1001/ 页面会多出刚才我们启动的 eureka-client 服务，访问 http://localhost:2001/disc 接口，会打印Services: [eureka-client]:2001信息。