SpringBoot动态修改yml配置文件的方法详解

< dependencies >

     < dependency >

         < groupId >org.springframework.boot</ groupId >

         < artifactId >spring-boot-starter-web</ artifactId >

     </ dependency >

     < dependency >

         < groupId >org.projectlombok</ groupId >

         < artifactId >lombok</ artifactId >

     </ dependency >

</ dependencies >

#端口号

server:

   port: 31091

spring:

   profiles:

     active: dev

coisini:

     mail: maggieq8324 @gmail .com

import lombok.extern.slf4j.Slf4j;

import org.springframework.boot.ApplicationArguments;

import org.springframework.boot.ApplicationRunner;

import org.springframework.stereotype.Component;

import java.util.Map;

import java.util.concurrent.Executors;

import java.util.concurrent.ScheduledExecutorService;

import java.util.concurrent.TimeUnit;

/**

  * @Description spring容器初始化完成后进行一些其他初始化操作

  * @date Mar 24, 2022

  * @version 1.0

  */

@Slf4j

@Component

public class InitializationConfig implements ApplicationRunner {

     private static ScheduledExecutorService executorService = Executors.newScheduledThreadPool( 1 );

     private static String profile;

     @Override

     public void run(ApplicationArguments applicationArguments) throws Exception {

         scheduleUpdateConf();

     }

     private void scheduleUpdateConf() {

         try {

             Map lhm = YmlUtil.loadYaml( "application.yml" );

             profile = (String) YmlUtil.getValByKey(lhm, "spring.profiles.active" );

         } catch (Exception e) {

             log.error( "加载配置文件application.yml异常" );

         }

         // TODO 开启定时刷新内存中配置文件内容

         log.info( "refresh config file start" );

         executorService.scheduleAtFixedRate(InitializationConfig::updateConfVal, 0 , 10 , TimeUnit.SECONDS);

         log.info( "refresh config file end" );

     }

     /**

      * 更新配置文件值

      */

     private static void updateConfVal(){

         try {

             Map lhm = YmlUtil.loadYaml( "application-" + profile + ".yml" );

             String mail = YmlUtil.getValByKey(lhm, "coisini.mail" ).toString();

             DynamicMailConfig instance = DynamicMailConfig.getInstance();

             if (!instance.getDynamicMail().equals(mail)) {

                 instance.setDynamicMail(mail);

                 log.info( "实时配置mail更新：" + instance.getDynamicMail());

             }

         } catch (Exception e){

             log.error( "更新配置文件值异常: " , e);

         }

     }

}

/**

  * @Description 动态邮箱单例

  * @date Mar 24, 2022

  * @version 1.0

  */

public class DynamicMailConfig {

     private static String mail;

     private final static DynamicMailConfig dynamic;

     static {

         dynamic = new DynamicMailConfig();

     }

     private DynamicMailConfig() {

         mail = "" ;

     }

     public static DynamicMailConfig getInstance() {

         return dynamic;

     }

     public String getDynamicMail() {

         return mail;

     }

     public void setDynamicMail(String mail) {

         this .mail = mail;

     }

}

import org.yaml.snakeyaml.Yaml;

import java.io.File;

import java.io.FileInputStream;

import java.io.InputStream;

import java.util.LinkedHashMap;

import java.util.Map;

/**

  * @Description 动态操作yml配置文件工具类

  *  【需要将config配置文件夹和项目jar包放在同级别目录下，这样修改config下的配置文件后，jvm才能及时得获取新的配置】

  * @date Mar 24, 2022

  * @version 1.0

  */

public class YmlUtil {

     public static LinkedHashMap loadYaml(String fileName) throws Exception{

         String path = System.getProperty( "user.dir" );

         File file = new File(path + "/config/" + fileName);

         InputStream in;

         if (file.exists()) {

             in = new FileInputStream(path + "/config/" + fileName);

         } else {

             // TODO 如果没有config文件夹，则从项目的resources目录下找

             in = YmlUtil. class .getClassLoader().getResourceAsStream(fileName);

         }

         LinkedHashMap lhm = new Yaml().loadAs(in, LinkedHashMap. class );

         return lhm;

     }

     public static Object getValByKey(Map lhm, String key) throws Exception{

         String[] keys = key.split( "[.]" );

         Map ymlInfo = lhm;

         for ( int i = 0 ; i < keys.length; i++) {

             Object value = ymlInfo.get(keys[i]);

             if (i < keys.length - 1 ) {

                 ymlInfo = (Map) value;

             } else if (value == null ) {

                 throw new Exception( "key不存在" );

             } else {

                 return value;

             }

         }

         return null ;

     }

}

@Slf4j

@RestController

public class TestController {

     @GetMapping ( "/getDynamicMail" )

     public String getDynamicMail() {

         String dynamicMail = DynamicMailConfig.getInstance().getDynamicMail();

         log.info( "getDynamicMail: " + dynamicMail);

         return dynamicMail;

     }

}