使用 Eureka 注册服务

在本章中，您将详细了解如何将 Spring Boot 微服务应用程序注册到 Eureka Server 中。在注册应用之前，请确保 Eureka Server 运行在 8761 端口或先构建 Eureka Server 并运行。有关构建 Eureka 服务器的更多信息，您可以参考上一章。

首先，您需要在我们的构建配置文件中添加以下依赖项，以将微服务注册到 Eureka 服务器。

Maven 用户可以在 pom.xml 文件中添加以下依赖项 −

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

Gradle 用户可以将以下依赖项添加到 build.gradle 文件中 −

compile('org.springframework.cloud:spring-cloud-starter-eureka')

现在，我们需要在主 Spring Boot 应用程序类文件中添加 @EnableEurekaClient 注解。 @EnableEurekaClient 注解使您的 Spring Boot 应用程序充当 Eureka 客户端。

主要的 Spring Boot 应用程序如下所示 −

package com.tutorialspoint.eurekaclient;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

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

要将 Spring Boot 应用程序注册到 Eureka Server 中，我们需要在 application.properties 文件或 application.yml 文件中添加以下配置，并在我们的配置中指定 Eureka Server URL。

application.yml 文件的代码如下 −

eureka:
   client:
      serviceUrl:
         defaultZone: http://localhost:8761/eureka
      instance:
      preferIpAddress: true
spring:
   application:
      name: eurekaclient

application.properties 文件的代码如下 −

eureka.client.serviceUrl.defaultZone  = http://localhost:8761/eureka
eureka.client.instance.preferIpAddress = true
spring.application.name = eurekaclient

现在，在主 Spring Boot 应用程序中添加 Rest Endpoint 以返回 String，并在构建配置文件中添加 Spring Boot Starter Web 依赖项。观察下面给出的代码 −

package com.tutorialspoint.eurekaclient;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableEurekaClient
@RestController
public class EurekaclientApplication {
   public static void main(String[] args) {
      SpringApplication.run(EurekaclientApplication.class, args);
   }
   @RequestMapping(value = "/")
   public String home() {
      return "Eureka Client application";
   }
}

整个配置文件如下所示。

对于 Maven 用户 - 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 
   http://maven.apache.org/xsd/maven-4.0.0.xsd">
   
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.tutorialspoint</groupId>
   <artifactId>eurekaclient</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>jar</packaging>

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

   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>1.5.9.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>Edgware.RELEASE</spring-cloud.version>
   </properties>

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

对于 Gradle 用户 – build.gradle

buildscript {
   ext {
      springBootVersion = '1.5.9.RELEASE'
   }
   repositories {
      mavenCentral()
   }
   dependencies {
      classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
   }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'

group = 'com.tutorialspoint'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8

repositories {
   mavenCentral()
}
ext {
   springCloudVersion = 'Edgware.RELEASE'
}
dependencies {
   compile('org.springframework.cloud:spring-cloud-starter-eureka')
   testCompile('org.springframework.boot:spring-boot-starter-test')
   compile('org.springframework.boot:spring-boot-starter-web')   
}
dependencyManagement {
   imports {
      mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
   }
}

您可以创建一个可执行的 JAR 文件，并使用以下 Maven 或 Gradle 命令运行 Spring Boot 应用程序 −

对于 Maven，您可以使用以下命令 −