Spring Cloud Alibaba系列之nacos：(3)服务集成Nacos

毕业版本依赖关系(推荐使用)

由于 Spring Boot 2.4+ 和以下版本之间变化较大，目前企业级客户老项目相关 Spring Boot 版本仍停留在 Spring Boot 2.4 以下，为了同时满足存量用户和新用户不同需求，社区以 Spring Boot 2.4 为分界线，同时维护 2.2.x 和 2021.x 两个分支迭代。

2021.x 分支

适配 Spring Boot 2.4, Spring Cloud 2021.x 版本及以上的 Spring Cloud Alibaba 版本如下表（最新版本用*标记）： (注意，该分支 Spring Cloud Alibaba 版本命名方式进行了调整, 未来将对应 Spring Cloud 版本，前三位为 Spring Cloud 版本，最后一位为扩展版本，比如适配 Spring Cloud 2021.0.1 版本对应的 Spring Cloud Alibaba 第一个版本为：2021.0.1.0，第个二版本为：2021.0.1.1，依此类推)

Spring Cloud Alibaba Version Spring Cloud Version Spring Boot Version

2021.0.1.0*

Spring Cloud 2021.0.1

2.6.3

2021.1

Spring Cloud 2020.0.1

2.4.2

2.2.x 分支

适配 Spring Boot 为 2.4, Spring Cloud Hoxton 版本及以下的 Spring Cloud Alibaba 版本如下表（最新版本用*标记）：

Spring Cloud Alibaba Version Spring Cloud Version Spring Boot Version

2.2.8.RELEASE*

Spring Cloud Hoxton.SR12

2.3.12.RELEASE

2.2.7.RELEASE

Spring Cloud Hoxton.SR12

2.3.12.RELEASE

Spring Cloud Alibaba Version	Spring Cloud Version	Spring Boot Version
2021.0.1.0*	Spring Cloud 2021.0.1	2.6.3
2021.1	Spring Cloud 2020.0.1	2.4.2

Spring Cloud Alibaba Version	Spring Cloud Version	Spring Boot Version
2.2.8.RELEASE*	Spring Cloud Hoxton.SR12	2.3.12.RELEASE
2.2.7.RELEASE	Spring Cloud Hoxton.SR12	2.3.12.RELEASE

这里选取：

Spring Cloud Alibaba Version：2.2.8.RELEASE
Spring Cloud Version：Spring Cloud Hoxton.SR12
Spring Boot Version：2.3.12.RELEASE

具体的版本依赖可以查看wiki：版本说明 · alibaba/spring-cloud-alibaba Wiki · GitHub

项目结构

Nacos 的服务发现功能，如下图示:

Nacos Server，nacos服务端，前面已经部署启动了
2个APP，即业务服务，注册到nacos里面
一个service-consumer服务消费方，一个server-provider服务提供方
这里也仿照这个结构，maven项目，一个auth认证服务，一个cipher加解密服务

添加依赖

在主pom上面添加


<properties>
        <spring-boot.version>2.3.12.RELEASEspring-boot.version>
        <spring-cloud.version>Hoxton.SR12spring-cloud.version>
        <spring-cloud-alibaba-nacos.version>2.2.7.RELEASEspring-cloud-alibaba-nacos.version>
        <java.version>1.8java.version>
    properties>
 
<dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-dependenciesartifactId>
                <version>${spring-boot.version}version>
                <type>pomtype>
                <scope>importscope>
            dependency>
            <dependency>
                <groupId>org.springframework.cloudgroupId>
                <artifactId>spring-cloud-dependenciesartifactId>
                <version>${spring-cloud.version}version>
                <type>pomtype>
                <scope>importscope>
            dependency>
            <dependency>
                <groupId>com.alibaba.cloudgroupId>
                <artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
                <version>${spring-cloud-alibaba-nacos.version}version>
            dependency>
 
            <dependency>
                <groupId>com.alibaba.nacosgroupId>
                <artifactId>nacos-clientartifactId>
                <version>2.1.1version>
            dependency>
        dependencies>
    dependencyManagement>

在auth服务pom里面引入


<dependencies>
<dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
 
        <dependency>
            <groupId>com.alibaba.cloudgroupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
            <exclusions>
                <exclusion>
                    <groupId>com.alibaba.nacosgroupId>
                    <artifactId>nacos-clientartifactId>
                exclusion>
            exclusions>
        dependency>
dependencies>

配置服务注册到 Nacos server

在 application.properties 中配置 Nacos server 的地址：


server.port=8080
spring.application.name=auth-service
 
spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848

开启服务注册发现功能

通过 Spring Cloud 原生注解 @EnableDiscoveryClient 开启服务注册发现功能：


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

启动服务，观察效果

服务注册

先启动nacos-server服务

启动auth服务，如果打印类似日志，表示注册成功

进入nacos控制台，查看服务列表

会看到刚才的auth服务已经成功注册到nacos了，同理可以注册启动cipher服务

服务调用

服务消费

在auth服务上创建一个接口，用作服务消费方，先创建RestTemplate实例


@SpringBootApplication
@EnableDiscoveryClient
public class AuthApplication
{
    public static void main(String[] args)
    {
        SpringApplication.run(AuthApplication.class, args);
    }
    
    @LoadBalanced
    @Bean
    public RestTemplate restTemplate()
    {
        return new RestTemplate();
    }
}

再创建controller


@RestController
public class TestController
{
    
    @Autowired
    private RestTemplate restTemplate;
    
    @RequestMapping(value = "/echo/{str}", method = RequestMethod.GET)
    public String echo(@PathVariable String str)
    {
        return restTemplate.getForObject("http://cipher-service/echo/" + str, String.class);
    }
}

服务提供

在cipher服务创建一个接口，用作服务提供方


@RestController
public class EchoController {
    @RequestMapping(value = "/echo/{string}", method = RequestMethod.GET)
    public String echo(@PathVariable String string) {
        return "Hello Nacos Discovery " + string;
    }
}

服务调用

启动 AuthApplication和CipherApplication，调用 http://localhost:8080/echo/2022，返回内容为 Hello Nacos Discovery 2022

示例工程代码

示例代码地址：tsm

可能出现的问题

java.lang.NoClassDefFoundError: com/alibaba/nacos/client/logging/NacosLogging

注意，如果是从官网的例子升级上来的，nacos-cliet版本也要升级到最新版本，比如1.1.0升到2.1.1，不然就会出现下面的错误


java.lang.NoClassDefFoundError: com/alibaba/nacos/client/logging/NacosLogging
	at com.alibaba.cloud.nacos.discovery.logging.NacosLoggingListener.onApplicationEvent(NacosLoggingListener.java:46) ~[spring-cloud-starter-alibaba-nacos-discovery-2.2.7.RELEASE.jar:2.2.7.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:80) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:53) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:342) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.builder.SpringApplicationBuilder.run(SpringApplicationBuilder.java:140) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.cloud.bootstrap.BootstrapApplicationListener.bootstrapServiceContext(BootstrapApplicationListener.java:212) [spring-cloud-context-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at org.springframework.cloud.bootstrap.BootstrapApplicationListener.onApplicationEvent(BootstrapApplicationListener.java:117) [spring-cloud-context-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at org.springframework.cloud.bootstrap.BootstrapApplicationListener.onApplicationEvent(BootstrapApplicationListener.java:74) [spring-cloud-context-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:80) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:53) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:342) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1247) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1236) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at com.tw.tsm.auth.AuthApplication.main(AuthApplication.java:11) [classes/:na]
Caused by: java.lang.ClassNotFoundException: com.alibaba.nacos.client.logging.NacosLogging

com.alibaba.nacos.api.exception.NacosException: Client not connected, current status:STARTING

用最新版本，2.x以上，除了开放8848nocos-server这个端口以外，还需要开放9848，9849这2个端口，否则启动会报以上错误


 
com.alibaba.nacos.api.exception.NacosException: Client not connected, current status:STARTING
	at com.alibaba.nacos.common.remote.client.RpcClient.request(RpcClient.java:655) ~[nacos-client-2.1.1.jar:na]
	at com.alibaba.nacos.common.remote.client.RpcClient.request(RpcClient.java:635) ~[nacos-client-2.1.1.jar:na]
	at com.alibaba.nacos.client.naming.remote.gprc.NamingGrpcClientProxy.requestToServer(NamingGrpcClientProxy.java:304) ~[nacos-client-2.1.1.jar:na]
	at com.alibaba.nacos.client.naming.remote.gprc.NamingGrpcClientProxy.doSubscribe(NamingGrpcClientProxy.java:255) ~[nacos-client-2.1.1.jar:na]
	at com.alibaba.nacos.client.naming.remote.gprc.NamingGrpcClientProxy.subscribe(NamingGrpcClientProxy.java:240) ~[nacos-client-2.1.1.jar:na]
	at com.alibaba.nacos.client.naming.remote.NamingClientProxyDelegate.subscribe(NamingClientProxyDelegate.java:160) ~[nacos-client-2.1.1.jar:na]
	at com.alibaba.nacos.client.naming.NacosNamingService.subscribe(NacosNamingService.java:404) ~[nacos-client-2.1.1.jar:na]
	at com.alibaba.cloud.nacos.discovery.NacosWatch.start(NacosWatch.java:134) ~[spring-cloud-starter-alibaba-nacos-discovery-2.2.7.RELEASE.jar:2.2.7.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:182) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.access$200(DefaultLifecycleProcessor.java:53) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:360) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:158) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:122) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:895) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:554) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:755) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:402) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1247) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1236) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at com.tw.tsm.auth.AuthApplication.main(AuthApplication.java:11) [classes/:na]

如果是云服务，要在安全组添加端口开放，并指定访问范围

如果是物理机，开放端口：

Centos7 查看防火墙状态,开放特定端口 - 明知山有小脑斧 - 博客园

参考资料

官网地址：Nacos Spring Cloud 快速开始

nacos连接异常 · Issue #I3TQ9B · 若依/RuoYi-Cloud - Gitee.com

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原文地址：https://blog.csdn.net/weigeshikebi/article/details/126818292