Spring Boot Eureka 服务注册



  • Eureka 服务注册

    在本章中,您将详细学习如何将Spring Boot 微服务应用程序注册到Eureka Server中。注册该应用程序之前,请确保Eureka Server在端口8761上运行,或者首先构建Eureka Server并运行它。有关构建Eureka服务器的更多信息,请参考上一章。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用户可以将以下依赖项添加到pom.xml文件中-
    
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>
    
    
    Gradle用户依赖的代码如下
    
    implementation 'org.springframework.cloud:spring-cloud-starter-netflix-eureka-client'
    
    
    完现在,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应用程序类如下所示-
    
    package com.jc2182.demo;
    
    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。
    下面给出了application.yml文件的代码-
    
    eureka:
       client:
          serviceUrl:
             defaultZone: http://localhost:8761/eureka
          instance:
          preferIpAddress: true
    spring:
       application:
          name: eurekaclient
    
    
    下面给出了application.properties文件的代码-
    
    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。遵守下面给出的代码-
    
    package com.jc2182.demo;
    
    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。
    Maven 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>2.3.0.BUILD-SNAPSHOT</version>
            <relativePath/> <!-- lookup parent from repository -->
        </parent>
        <groupId>com.jc2182</groupId>
        <artifactId>demo</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>demo</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <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.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>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
        <repositories>
            <repository>
                <id>spring-milestones</id>
                <name>Spring Milestones</name>
                <url>https://repo.spring.io/milestone</url>
            </repository>
            <repository>
                <id>spring-snapshots</id>
                <name>Spring Snapshots</name>
                <url>https://repo.spring.io/snapshot</url>
                <snapshots>
                    <enabled>true</enabled>
                </snapshots>
            </repository>
        </repositories>
        <pluginRepositories>
            <pluginRepository>
                <id>spring-milestones</id>
                <name>Spring Milestones</name>
                <url>https://repo.spring.io/milestone</url>
            </pluginRepository>
            <pluginRepository>
                <id>spring-snapshots</id>
                <name>Spring Snapshots</name>
                <url>https://repo.spring.io/snapshot</url>
                <snapshots>
                    <enabled>true</enabled>
                </snapshots>
            </pluginRepository>
        </pluginRepositories>
    
    </project>
    
    
    Gradle 用户 – build.gradle
    
    plugins {
        id 'org.springframework.boot' version '2.3.0.BUILD-SNAPSHOT'
        id 'io.spring.dependency-management' version '1.0.9.RELEASE'
        id 'java'
    }
    
    group = 'com.jc2182'
    version = '0.0.1-SNAPSHOT'
    sourceCompatibility = '1.8'
    
    repositories {
        mavenCentral()
        maven { url 'https://repo.spring.io/milestone' }
        maven { url 'https://repo.spring.io/snapshot' }
    }
    
    ext {
        set('springCloudVersion', "Hoxton.BUILD-SNAPSHOT")
    }
    
    dependencies {
        implementation 'org.springframework.boot:spring-boot-starter-web'
        implementation 'org.springframework.cloud:spring-cloud-starter-netflix-eureka-client'
        testImplementation('org.springframework.boot:spring-boot-starter-test') {
            exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
        }
    }
    
    dependencyManagement {
        imports {
            mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
        }
    }
    
    test {
        useJUnitPlatform()
    }
    
    
    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,请使用以下命令
    
    mvn clean install
    
    
    在“BUILD SUCCESS”之后,您可以在target目录下找到JAR文件。
    对于Gradle,请使用以下命令-
    
    gradle clean build
    
    
    在“BUILD SUCCESSFUL”之后,您可以在build/libs目录下找到JAR文件。
    现在,使用如下所示的命令运行JAR文件:
    
    java –jar <JARFILE>
    
    
    您会发现该应用程序已在Tomcat端口8080上启动。
    在您的Web浏览器中访问URL http://localhost:8761/,您可以看到Eureka Client应用程序已在Eureka Server中注册。
    现在,在Web浏览器中访问URL http://localhost:8080/并查看Rest Endpoint输出。