前一篇文章nacos-简介和初体验（一）我们已经在服务器部署了nacos应用了，接下来让我们尝试在springcloud中整合nacos，代替我们springcloud config。

一、新建springcloud工程

新建一个springboot工程，pom文件如下：

<?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>2.3.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.eujian</groupId>
    <artifactId>nacos-config</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>nacos-config</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.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
            <version>2.2.5.RELEASE</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

新建一个测试的controller

import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/config")
@RefreshScope
public class DemoController {

    @Value("${demoKey:demoKey}")
    private String demoKey;

    /**
     * http://localhost:8081/config/getdemo
     */
    @GetMapping("getdemo")
    public String demo(){
        return demoKey;
    }
}

由于nacos在修改配置的时候会触发spring内部的event事件，所以我们可以监听这个event来做一些日志的打印。和特殊的事件变更。

新建自己的事件变更监听类

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.context.environment.EnvironmentChangeEvent;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.event.EventListener;
import org.springframework.core.env.Environment;

import java.util.Set;
@Slf4j
@Configuration
public class ConfigChangeLister {
    @Autowired
    private Environment environment;

    @EventListener
    public void getUserEvent(EnvironmentChangeEvent event) {
        Set<String> keys = event.getKeys();
        keys.forEach(k->{
            String v = environment.getProperty(k);
            log.info("配置变更，key={},value={}",k,v);
        });
    }
}

新建一个bootstrap.properties文件

server.port=8081
spring.cloud.nacos.config.server-addr=localhost:8848
spring.application.name=config-demo
spring.cloud.nacos.config.file-extension=properties