springboot 定时任务实现SchedulingConfigurer接口，修改定时任务不重启项目

ゝ一纸荒年。 2022-12-01 15:53 355阅读 0赞

## 业务场景描述： ##

定时任务的任务名称，cron（定时任务表达式），定时任务开关，存储在数据库表中。在不重启项目的情况下，修改定时任务表达式，可以实时获取新的定时任务执行时间规则；修改定时任务执行状态，可以随时开关定时任务。

使用技术：基于接口  **SchedulingConfigurer**

## 1、建表 管理定时任务 ##

DROP TABLE IF EXISTS `scheduled`;
    CREATE TABLE `scheduled` (
      `name` varchar(20) DEFAULT NULL,
      `cron` varchar(30) DEFAULT NULL,
      `open` tinyint(1) DEFAULT NULL COMMENT '1开启， 其他为关闭'
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
    
    -- ----------------------------
    -- Records of scheduled
    -- ----------------------------
    INSERT INTO `scheduled` VALUES ('demo1', '0/5 * * * * ?', '1');
    INSERT INTO `scheduled` VALUES ('demo2', '0/6 * * * * ?', '1');

## 2、代码实现 ##

### 定时任务配置类： ###

package com.example.demo.scheduled;
    
    import com.google.common.util.concurrent.ThreadFactoryBuilder;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    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.concurrent.Executor;
    import java.util.concurrent.Executors;
    import java.util.concurrent.ThreadFactory;
    
    /**
     * @Description: 基于接口SchedulingConfigurer的动态定时任务
     * @Author: 
     * @Date: 2020-08-27
     */
    @Configuration
    @EnableScheduling
    public abstract class ConfigurerSchedulingDemo implements SchedulingConfigurer {
    
        //定时任务周期表达式
        private String cron;
        /** 
         * @Description:  重写配置定时任务的方法
         * @param: scheduledTaskRegistrar 
         * @return: void 
         * @Author: 
         * @Date: 2020/8/28
         */
        @Override
        public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) {
            scheduledTaskRegistrar.setScheduler(taskScheduler());
            scheduledTaskRegistrar.addTriggerTask(
                    //执行定时任务
                    () ->
                    {
                        taskService();
                    },
                    //设置触发器
                    triggerContext -> {
    
                       cron = getCron();//获取定时任务周期表达式
    
                        CronTrigger trigger = new CronTrigger(cron);
    
                        return trigger.nextExecutionTime(triggerContext);
                    }
            );
    
        }
    
        @Bean
        public Executor taskScheduler() {
            //设置线程名称
            ThreadFactory namedThreadFactory = new ThreadFactoryBuilder().setNameFormat("demo-pool-%d").build();
            //创建线程池
            return Executors.newScheduledThreadPool(5, namedThreadFactory);
        }
    
        /**
         * @Description: 执行定时任务
         * @param:
         * @return: void
         * @Author: 
         * @Date: 2020/8/28
         */
        public abstract void taskService();
    
        /**
         * @Description: 获取定时任务周期表达式
         * @param:
         * @return: java.lang.String
         * @Author: 
         * @Date: 2020/8/28
         */
        public abstract String getCron();
    
    }

### 定时任务1 ###

package com.example.demo.scheduled;
    
    import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
    import com.example.demo.dao.CronMapper;
    import com.example.demo.entity.Scheduled;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.annotation.Configuration;
    
    import java.time.LocalDateTime;
    
    /**
     * @Description:
     * @Author: 
     * @Date: 2020-08-27
     */
    @Configuration
    public class TaskDemo extends ConfigurerSchedulingDemo {
    
        @Autowired      //注入mapper
        @SuppressWarnings("all")
        CronMapper cronMapper;
    
        @Override
        public void taskService() {
            Integer open = getOpen();
            if (1== open){
                System.out.println("定时任务demo1:"
                        + LocalDateTime.now()+"，线程名称："+Thread.currentThread().getName()
                        + " 线程id："+Thread.currentThread().getId());
            }
        }
    
        @Override
        public String getCron() {
            QueryWrapper<Scheduled> queryWrapper = new QueryWrapper<>();
            queryWrapper.eq("name","demo1");
            String cron = cronMapper.selectOne(queryWrapper).getCron();
            return cron;
        }
    
        public Integer getOpen() {
            QueryWrapper<Scheduled> queryWrapper = new QueryWrapper<>();
            queryWrapper.eq("name", "demo1");
            Integer open = cronMapper.selectOne(queryWrapper).getOpen();
            return open;
        }
    
    }

###    定时任务2 ###

package com.example.demo.scheduled;
    
    import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
    import com.example.demo.dao.CronMapper;
    import com.example.demo.entity.Scheduled;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.annotation.Configuration;
    
    import java.time.LocalDateTime;
    
    /**
     * @Description:
     * @Author: 
     * @Date: 2020-08-27
     */
    @Configuration
    public class TaskDemo1 extends ConfigurerSchedulingDemo {
    
        @Autowired      //注入mapper
        @SuppressWarnings("all")
        CronMapper cronMapper;
    
        @Override
        public void taskService() {
            Integer open = getOpen();
            if (1== open){
                System.out.println("定时任务demo2:"
                        + LocalDateTime.now()+"，线程名称："+Thread.currentThread().getName()
                        + " 线程id："+Thread.currentThread().getId());
            }
        }
    
        @Override
        public String getCron() {
            QueryWrapper<Scheduled> queryWrapper = new QueryWrapper<>();
            queryWrapper.eq("name","demo2");
            String cron = cronMapper.selectOne(queryWrapper).getCron();
            return cron;
        }
    
        public Integer getOpen() {
            QueryWrapper<Scheduled> queryWrapper = new QueryWrapper<>();
            queryWrapper.eq("name", "demo2");
            Integer open = cronMapper.selectOne(queryWrapper).getOpen();
            return open;
        }
    }

## 效果展示： ##

启动项目：控制台输出展示

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5waW5nMTk5Mw_size_16_color_FFFFFF_t_70][]

修改数据库 demo1的执行时间为每15秒一次：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5waW5nMTk5Mw_size_16_color_FFFFFF_t_70 1][]

关闭demo1的定时任务，将demo1的open状态改为0：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5waW5nMTk5Mw_size_16_color_FFFFFF_t_70 2][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5waW5nMTk5Mw_size_16_color_FFFFFF_t_70]: /images/20221123/2575c868ac14455485a77b57a84b6d0c.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5waW5nMTk5Mw_size_16_color_FFFFFF_t_70 1]: /images/20221123/221bef716e644419a6d260bf0ff04375.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5waW5nMTk5Mw_size_16_color_FFFFFF_t_70 2]: /images/20221123/4df1f143300d469a9a525a09d67abfea.png