在Spring Boot项目中,通过@EnableScheduling可启用Spring自带的定时任务支持,在通过@Scheduled注解定义定时任务,但是通过注解只能编写固定时间的定时任务,无法动态调整定时间隔,可通过实现SchedulingConfigurer接口实现动态定时任务注册。
参考代码:
package org.cent.demo.scanner.schedule;import lombok.AllArgsConstructor;import lombok.Data;import lombok.extern.slf4j.Slf4j;import org.springframework.context.annotation.Configuration;import org.springframework.scheduling.Trigger;import org.springframework.scheduling.annotation.EnableScheduling;import org.springframework.scheduling.annotation.SchedulingConfigurer;import org.springframework.scheduling.config.ScheduledTaskRegistrar;import org.springframework.scheduling.support.CronTrigger;import java.util.Arrays;import java.util.List;/** * @author: cent * @email: 292462859@qq.com * @date: 2019/1/16. * @description: */@Configuration@EnableScheduling@Slf4jpublic class DynamicSchedule implements SchedulingConfigurer { /** * 测试数据,实际可从数据库获取 */ private List<Task> tasks = Arrays.asList( new Task(1, "任务1", "*/30 * * * * *"), new Task(2, "任务2", "*/30 * * * * *"), new Task(3, "任务3", "*/30 * * * * *"), new Task(4, "任务4", "*/30 * * * * *"), new Task(5, "任务5", "*/30 * * * * *"), new Task(6, "任务6", "*/30 * * * * *"), new Task(7, "任务7", "*/30 * * * * *"), new Task(8, "任务8", "*/30 * * * * *"), new Task(9, "任务9", "*/30 * * * * *"), new Task(10, "任务10", "*/30 * * * * *") ); @Override public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) { tasks.forEach(task -> { //任务执行线程 Runnable runnable = () -> log.info("execute task {}", task.getId()); //任务触发器 Trigger trigger = triggerContext -> { //获取定时触发器,这里可以每次从数据库获取最新记录,更新触发器,实现定时间隔的动态调整 CronTrigger cronTrigger = new CronTrigger(task.getCron()); return cronTrigger.nextExecutionTime(triggerContext); }; //注册任务 scheduledTaskRegistrar.addTriggerTask(runnable, trigger); }); } @Data @AllArgsConstructor static class Task { /** * 主键ID */ private int id; /** * 任务名称 */ private String name; /** * cron表达式 */ private String cron; } }
作者:centychen
链接:https://www.jianshu.com/p/546631cc2b8f