Nacos--在Spring cloud中使用Spring Cloud Alibaba Nacos Discovery（服务注册+配置管理示例）
开发套路放在前：
a 加依赖
b 加注解
c 写配置
-
父pom.xml（依赖约束）
<?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.zeng</groupId>
<artifactId>nacosTest</artifactId>
<version>1.0-SNAPSHOT</version>
<modules>
<module>quickstart‐provider</module>
</modules>
<packaging>pom</packaging>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencyManagement>
<dependencies>
<!--spring-cloud-alibaba-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>2.1.0.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<!--spring-cloud-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Greenwich.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<!--spring-boot-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>2.1.3.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.10</version>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>2.2.5.RELEASE</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
</configuration>
</plugin>
</plugins>
</build>
</project>-
子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">
<parent>
<artifactId>nacosTest</artifactId>
<groupId>com.zeng</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>quickstart-provider</artifactId>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--需要引入该jar才能使bootstrap配置文件生效-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
</dependencies>
</project>-
nacos配置
-
测试controller
@RestController
@Slf4j
@RefreshScope
public class ServiceTest {
@Value("${common.config1:local}")
private String testValue;
@GetMapping(value = "/getConfig")
public String getConfig() {
log.debug("debug:common.config1="+testValue);
log.info("info:common.config1="+testValue);
return testValue;//可动态更新
}
}-
bootstrap.yml
spring: application: name: quickstart-provider cloud: nacos: discovery: server-addr: 192.168.31.119:8848 namespace: 405e2609-c439-4b1e-b177-82f5a5ce2a0b config: server-addr: 192.168.31.119:8848 file-extension: yaml namespace: 405e2609-c439-4b1e-b177-82f5a5ce2a0b group: TEST_GROUP
-
启动类
@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class ProviderApp {
public static void main(String[] args) {
SpringApplication.run(ProviderApp.class,args);
}
}
@EnableDiscoveryClient 在spring cloud项目中表明此项目是一个注册发现客户端，这里注册服务发现使用的是Nacos
@EnableFeignClients 开启FeignClient
注：如果只是注册服务提供者到nacos，@EnableDiscoveryClient和@EnableFeignClients可以省略，但大部分服务不仅是提供者，也是消费者，所以习惯把这两个注解加上。
-
测试
打开http://127.0.0.1:8848/nacos/的服务列表：
测试配置管理成功：
并能在线更新配置（日志级别）成功：
遇到如下错误：
java.lang.IllegalArgumentException: no server available
at com.alibaba.nacos.client.naming.net.NamingProxy.reqAPI(NamingProxy.java:438) ~[nacos-client-1.1.1.jar:na]
at com.alibaba.nacos.client.naming.net.NamingProxy.reqAPI(NamingProxy.java:386) ~[nacos-client-1.1.1.jar:na]
at com.alibaba.nacos.client.naming.net.NamingProxy.sendBeat(NamingProxy.java:309) ~[nacos-client-1.1.1.jar:na]
at com.alibaba.nacos.client.naming.beat.BeatReactor$BeatTask.run(BeatReactor.java:92) [nacos-client-1.1.1.jar:na]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_201]
at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266) [na:1.8.0_201]
at java.util.concurrent.FutureTask.run(FutureTask.java) [na:1.8.0_201]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_201]
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) [na:1.8.0_201]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_201]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_201]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_201]
可能是因为你加了nacos服务发现的依赖，但是没有在bootstrap.yml中配置
建议：
1 因为是配置管理和服务发现都使用nacos，所以最好先测试好配置管理后，再配置服务发现
2 可能有的小伙伴和我一样，想把服务发现的配置放到nacos的配置管理中，其实完全没必要，因为配置管理中的服务发现配置修改后，服务实例必需重启才会生效。