经过网上搜索学习后，特此记录如何在SpringBoot项目中实现动态定时任务。
因为只是一个demo，所以只引入了需要的依赖：
<dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-log4j2</artifactId><optional>true</optional></dependency><!-- spring boot 2.3版本后，如果需要使用校验，需手动导入validation包--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-validation</artifactId></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency>
</dependencies>启动类：
package com.wl.demo;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;/*** @author wl*/
@EnableScheduling
@SpringBootApplication
public class DemoApplication {public static void main(String[] args) {SpringApplication.run(DemoApplication.class, args);System.out.println("(*^▽^*)启动成功!!!(〃'▽'〃)");}
}配置文件application.yml，只定义了服务端口：
server:port: 8089定时任务执行时间配置文件：task-config.ini:
printTime.cron=0/10 * * * * ?定时任务执行类：
package com.wl.demo.task;import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.PropertySource;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.TriggerContext;
import org.springframework.scheduling.annotation.SchedulingConfigurer;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;
import org.springframework.scheduling.support.CronTrigger;
import org.springframework.stereotype.Component;import java.time.LocalDateTime;
import java.util.Date;/*** 定时任务* @author wl*/
@Data
@Slf4j
@Component
@PropertySource("classpath:/task-config.ini")
public class ScheduleTask implements SchedulingConfigurer {@Value("${printTime.cron}")private String cron;@Overridepublic void configureTasks(ScheduledTaskRegistrar taskRegistrar) {// 动态使用cron表达式设置循环间隔taskRegistrar.addTriggerTask(new Runnable() {@Overridepublic void run() {log.info("Current time： {}", LocalDateTime.now());}}, new Trigger() {@Overridepublic Date nextExecutionTime(TriggerContext triggerContext) {// 使用CronTrigger触发器，可动态修改cron表达式来操作循环规则CronTrigger cronTrigger = new CronTrigger(cron);Date nextExecutionTime = cronTrigger.nextExecutionTime(triggerContext);return nextExecutionTime;}});}
}编写一个接口，使得可以通过调用接口动态修改该定时任务的执行时间：
package com.wl.demo.controller;import com.wl.demo.task.ScheduleTask;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;/*** @author wl*/
@Slf4j
@RestController
@RequestMapping("/test")
public class TestController {private final ScheduleTask scheduleTask;@Autowiredpublic TestController(ScheduleTask scheduleTask) {this.scheduleTask = scheduleTask;}@GetMapping("/updateCron")public String updateCron(String cron) {log.info("new cron :{}", cron);scheduleTask.setCron(cron);return"ok";}
}启动项目，可以看到任务每10秒执行一次：
访问接口，传入请求参数cron表达式，将定时任务修改为15秒执行一次：
可以看到任务变成了15秒执行一次
除了上面的借助cron表达式的方法，还有另一种触发器，区别于CronTrigger触发器，该触发器可随意设置循环间隔时间，不像cron表达式只能定义小于等于间隔59秒。
package com.wl.demo.task;import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.PropertySource;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.TriggerContext;
import org.springframework.scheduling.annotation.SchedulingConfigurer;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;
import org.springframework.scheduling.support.CronTrigger;
import org.springframework.scheduling.support.PeriodicTrigger;
import org.springframework.stereotype.Component;import java.time.LocalDateTime;
import java.util.Date;/*** 定时任务* @author wl*/
@Data
@Slf4j
@Component
@PropertySource("classpath:/task-config.ini")
public class ScheduleTask implements SchedulingConfigurer {@Value("${printTime.cron}")private String cron;private Long timer = 10000L;@Overridepublic void configureTasks(ScheduledTaskRegistrar taskRegistrar) {// 动态使用cron表达式设置循环间隔taskRegistrar.addTriggerTask(new Runnable() {@Overridepublic void run() {log.info("Current time： {}", LocalDateTime.now());}}, new Trigger() {@Overridepublic Date nextExecutionTime(TriggerContext triggerContext) {// 使用CronTrigger触发器，可动态修改cron表达式来操作循环规则
// CronTrigger cronTrigger = new CronTrigger(cron);
// Date nextExecutionTime = cronTrigger.nextExecutionTime(triggerContext);// 使用不同的触发器，为设置循环时间的关键，区别于CronTrigger触发器，该触发器可随意设置循环间隔时间，单位为毫秒PeriodicTrigger periodicTrigger = new PeriodicTrigger(timer);Date nextExecutionTime = periodicTrigger.nextExecutionTime(triggerContext);return nextExecutionTime;}});}
}增加一个修改时间的接口：
package com.wl.demo.controller;import com.wl.demo.task.ScheduleTask;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;/*** @author wl*/
@Slf4j
@RestController
@RequestMapping("/test")
public class TestController {private final ScheduleTask scheduleTask;@Autowiredpublic TestController(ScheduleTask scheduleTask) {this.scheduleTask = scheduleTask;}@GetMapping("/updateCron")public String updateCron(String cron) {log.info("new cron :{}", cron);scheduleTask.setCron(cron);return"ok";}@GetMapping("/updateTimer")public String updateTimer(Long timer) {log.info("new timer :{}", timer);scheduleTask.setTimer(timer);return"ok";}
}测试结果：
