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首页 > 软件编程 > java > SpringBoot使用Nacos动态配置管理时定时器不执行

SpringBoot使用Nacos动态配置管理时定时器不执行的问题及解决

作者:朝如青丝·暮成雪

本文详细解析了在使用Nacos 7.4.1版本进行定时任务配置动态刷新时遇到的问题的解决方案,包括pom依赖配置、配置类懒加载机制以及Nacos配置中心示例配置

说明

nacos服务版本:1.4.1

问题

在定时器类中使用nacos注解动态刷新,变更配置中心的配置后,项目监听到了变更,但是会使定时器无法执行的问题。

解决方案

1. pom依赖

<?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>2.3.2.RELEASE</version>
        <relativePath/>
    </parent>
    <groupId>com.tyg</groupId>
    <artifactId>nacos-demo</artifactId>
    <version>0.0.1</version>
    <name>nacos-demo</name>
    <description>测试</description>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <maven.compiler.encoding>UTF-8</maven.compiler.encoding>
        <java.version>1.8</java.version>
        <spring.cloud.alibaba.version>2.2.5.RELEASE</spring.cloud.alibaba.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
            <version>${spring.cloud.alibaba.version}</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <version>${spring.cloud.alibaba.version}</version>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.3.2.RELEASE</version>
            </dependency>
            <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-dependencies -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR4</version>
                <type>pom</type>
                <scope>runtime</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.2.RELEASE</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

2. nacos动态配置的数据统一放到一个类中

在更新nacos配置后,配置类会出现懒加载,即访问时才加载,如果将变更的变量放到定时器类中,那么定时器就会懒加载,导致定时器无法执行!

import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.context.annotation.Configuration;

/**
 * nacos统一动态配置类
 * @author tyg
 * @date 2021-04-15 15:57
 */
@RefreshScope
@Configuration
public class DynamicConfig {

    @Value("${demo.number:10}")
    public Integer number;

    public Integer getNumber(){
        return this.number;
    }
}

3. 定时器中调用示例

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * 定时器demo
 * @author tyg
 * @date 2021-04-15 9:50
 */
@Component
public class DemoTask {

    @Resource
    private DynamicConfig dynamicConfig;

    @Scheduled(fixedDelay = 5000)
    public void run(){
        System.out.println(new SimpleDateFormat("HH:mm:ss").format(new Date()) + " demo.number=" + dynamicConfig.getNumber());
    }
}

4. bootstrap.yml配置示例

server:
  port: 8800
spring:
  application:
    name: nacos-demo
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
      config:
        server-addr: ${spring.cloud.nacos.discovery.server-addr}
        file-extension: yaml

5. nacos配置中心示例

6. 执行日志

总结

以上为个人经验,希望能给大家一个参考,也希望大家多多支持脚本之家。

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