环境准备

注册中心：nacos

jdk版本：jdk17

Spring Cloud Alibaba版本组合：

• Spring Boot 3.0.10
• Spring Cloud 2022.0.4
• Spring Cloud Alibaba 2022.0.0.0

项目结构介绍

|-- demo-framework
    |-- demo-provider-service(服务提供方)

demo-framework：父级pom，负责进行依赖管理、

demo-provider-service：服务提供方，本案例中将用于集成注册中心

步骤一：确认nacos已启动

访问naco地址（http://127.0.0.1:8848/nacos）可以正常访问！

步骤二：创建demo-framework工程

该工程为pom类型，负责管理整个工程的依赖以及自定义属性，仅有pom文件。

pom.xml

<artifactId>demo-framework</artifactId>
    <packaging>pom</packaging>
    <modules>
        <module>demo-provider-service</module>
    </modules>
    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <!-- 目前最新版本 jdk要求17-->
        <spring.cloud.alibaba.version>2022.0.0.0</spring.cloud.alibaba.version>
        <spring.cloud.version>2022.0.4</spring.cloud.version>
        <spring.boot.version>3.0.10</spring.boot.version>
        <alibaba.fastjson2.version>2.0.39</alibaba.fastjson2.version>
    </properties>
    <dependencyManagement>
        <dependencies>
            <!-- spring boot-->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring.boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- spring cloud-->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring.cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- spring cloud alibaba-->
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring.cloud.alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

步骤三：创建demo-provider-service模块

web服务，引入注册中心。

1. pom.xml中引入spring-cloud-starter-alibaba-nacos-discovery依赖

 <!-- nacos服务发现 -->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>

2. application.yml引入注册中心相关信息

spring:
  application:
    name: provider-service
  cloud:
    nacos:
      discovery:
        enabled: true
        username: nacos
        password: nacos
        server-addr: 127.0.0.1:8848

3. 应用启动类

ProviderServiceApplication.java

package demo.provider.service;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

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

运行ProviderServiceApplication即可启动应用。

结果验证

访问nacos，菜单-服务列表，可以看到provider-service有实例在线即服务注册成功。

拓展：省略注解@EnableDiscoveryClient

可以通过在application文件中配置spring.cloud.discovery.enabled=true来省略启动类上注解@EnableDiscoveryClient，以起到同样的效果。

拓展：自动装配原理

1. 通过查看依赖spring-cloud-starter-alibaba-nacos-discovery中META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports文件内容可知相关自动装配类。

com.alibaba.cloud.nacos.discovery.NacosDiscoveryAutoConfiguration
com.alibaba.cloud.nacos.endpoint.NacosDiscoveryEndpointAutoConfiguration
com.alibaba.cloud.nacos.registry.NacosServiceRegistryAutoConfiguration
com.alibaba.cloud.nacos.discovery.NacosDiscoveryClientConfiguration
com.alibaba.cloud.nacos.discovery.NacosDiscoveryHeartBeatConfiguration
com.alibaba.cloud.nacos.discovery.reactive.NacosReactiveDiscoveryClientConfiguration
com.alibaba.cloud.nacos.discovery.configclient.NacosConfigServerAutoConfiguration
com.alibaba.cloud.nacos.loadbalancer.LoadBalancerNacosAutoConfiguration
com.alibaba.cloud.nacos.NacosServiceAutoConfiguration
com.alibaba.cloud.nacos.util.UtilIPv6AutoConfiguration