前言前端
在咱们平常的开发中,不少时候,定时任务都不是写死的,而是写到数据库中,从而实现定时任务的动态配置,下面就经过一个简单的示例,来实现这个功能。java
1、新建一个springboot工程,并添加依赖spring
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency><!-- 为了方便测试,此处使用了内存数据库 --> <groupId>com.h2database</groupId> <artifactId>h2</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.quartz-scheduler</groupId> <artifactId>quartz</artifactId> <version>2.2.1</version> <exclusions> <exclusion> <artifactId>slf4j-api</artifactId> <groupId>org.slf4j</groupId> </exclusion> </exclusions> </dependency> <dependency><!-- 该依赖必加,里面有sping对schedule的支持 --><groupId>org.springframework</groupId><artifactId>spring-context-support</artifactId></dependency>
2、配置文件application.propertiessql
# 服务器端口号server.port=7902# 是否生成ddl语句spring.jpa.generate-ddl=false # 是否打印sql语句spring.jpa.show-sql=true # 自动生成ddl,因为指定了具体的ddl,此处设置为nonespring.jpa.hibernate.ddl-auto=none# 使用H2数据库spring.datasource.platform=h2# 指定生成数据库的schema文件位置spring.datasource.schema=classpath:schema.sql# 指定插入数据库语句的脚本位置spring.datasource.data=classpath:data.sql# 配置日志打印信息logging.level.root=INFOlogging.level.org.hibernate=INFOlogging.level.org.hibernate.type.descriptor.sql.BasicBinder=TRACElogging.level.org.hibernate.type.descriptor.sql.BasicExtractor=TRACElogging.level.com.itmuch=DEBUG
3、Entity类数据库
package com.chhliu.springboot.quartz.entity;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;@Entitypublic class Config { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @Column private String cron; /** * @return the id */ public Long getId() { return id; }……此处省略getter和setter方法……}
4、任务类api
package com.chhliu.springboot.quartz.entity;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.context.annotation.Configuration;import org.springframework.scheduling.annotation.EnableScheduling;import org.springframework.stereotype.Component;@Configuration@Component // 此注解必加@EnableScheduling // 此注解必加public class ScheduleTask { private static final Logger LOGGER = LoggerFactory.getLogger(ScheduleTask.class); public void sayHello(){ LOGGER.info("Hello world, i'm the king of the world!!!"); }}
5、Quartz配置类springboot
因为springboot追求零xml配置,因此下面会以配置Bean的方式来实现服务器
package com.chhliu.springboot.quartz.entity;import org.quartz.Trigger;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.scheduling.quartz.CronTriggerFactoryBean;import org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean;import org.springframework.scheduling.quartz.SchedulerFactoryBean;@Configurationpublic class QuartzConfigration { /** * attention: * Details:配置定时任务 */ @Bean(name = "jobDetail") public MethodInvokingJobDetailFactoryBean detailFactoryBean(ScheduleTask task) {// ScheduleTask为须要执行的任务 MethodInvokingJobDetailFactoryBean jobDetail = new MethodInvokingJobDetailFactoryBean(); /* * 是否并发执行 * 例如每5s执行一次任务,可是当前任务尚未执行完,就已通过了5s了, * 若是此处为true,则下一个任务会执行,若是此处为false,则下一个任务会等待上一个任务执行完后,再开始执行 */ jobDetail.setConcurrent(false); jobDetail.setName("srd-chhliu");// 设置任务的名字 jobDetail.setGroup("srd");// 设置任务的分组,这些属性均可以存储在数据库中,在多任务的时候使用 /* * 为须要执行的实体类对应的对象 */ jobDetail.setTargetObject(task); /* * sayHello为须要执行的方法 * 经过这几个配置,告诉JobDetailFactoryBean咱们须要执行定时执行ScheduleTask类中的sayHello方法 */ jobDetail.setTargetMethod("sayHello"); return jobDetail; } /** * attention: * Details:配置定时任务的触发器,也就是何时触发执行定时任务 */ @Bean(name = "jobTrigger") public CronTriggerFactoryBean cronJobTrigger(MethodInvokingJobDetailFactoryBean jobDetail) { CronTriggerFactoryBean tigger = new CronTriggerFactoryBean(); tigger.setJobDetail(jobDetail.getObject()); tigger.setCronExpression("0 30 20 * * ?");// 初始时的cron表达式 tigger.setName("srd-chhliu");// trigger的name return tigger; } /** * attention: * Details:定义quartz调度工厂 */ @Bean(name = "scheduler") public SchedulerFactoryBean schedulerFactory(Trigger cronJobTrigger) { SchedulerFactoryBean bean = new SchedulerFactoryBean(); // 用于quartz集群,QuartzScheduler 启动时更新己存在的Job bean.setOverwriteExistingJobs(true); // 延时启动,应用启动1秒后 bean.setStartupDelay(1); // 注册触发器 bean.setTriggers(cronJobTrigger); return bean; }}
6、定时查库,并更新任务并发
package com.chhliu.springboot.quartz.entity;import javax.annotation.Resource;import org.quartz.CronScheduleBuilder;import org.quartz.CronTrigger;import org.quartz.JobDetail;import org.quartz.Scheduler;import org.quartz.SchedulerException;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.context.annotation.Configuration;import org.springframework.scheduling.annotation.EnableScheduling;import org.springframework.scheduling.annotation.Scheduled;import org.springframework.stereotype.Component;import com.chhliu.springboot.quartz.repository.ConfigRepository;@Configuration@EnableScheduling@Componentpublic class ScheduleRefreshDatabase { @Autowired private ConfigRepository repository; @Resource(name = "jobDetail") private JobDetail jobDetail; @Resource(name = "jobTrigger") private CronTrigger cronTrigger; @Resource(name = "scheduler") private Scheduler scheduler; @Scheduled(fixedRate = 5000) // 每隔5s查库,并根据查询结果决定是否从新设置定时任务 public void scheduleUpdateCronTrigger() throws SchedulerException { CronTrigger trigger = (CronTrigger) scheduler.getTrigger(cronTrigger.getKey()); String currentCron = trigger.getCronExpression();// 当前Trigger使用的 String searchCron = repository.findOne(1L).getCron();// 从数据库查询出来的 System.out.println(currentCron); System.out.println(searchCron); if (currentCron.equals(searchCron)) { // 若是当前使用的cron表达式和从数据库中查询出来的cron表达式一致,则不刷新任务 } else { // 表达式调度构建器 CronScheduleBuilder scheduleBuilder = CronScheduleBuilder.cronSchedule(searchCron); // 按新的cronExpression表达式从新构建trigger trigger = (CronTrigger) scheduler.getTrigger(cronTrigger.getKey()); trigger = trigger.getTriggerBuilder().withIdentity(cronTrigger.getKey()) .withSchedule(scheduleBuilder).build(); // 按新的trigger从新设置job执行 scheduler.rescheduleJob(cronTrigger.getKey(), trigger); currentCron = searchCron; } }}
6、相关脚本app
一、data.sql
insert into config(id,cron) values(1,'0 0/2 * * * ?'); # 每2分钟执行一次定时任务
二、schema.sql
drop table config if exists;create table config( id bigint generated by default as identity, cron varchar(40), primary key(id));
6、运行测试
测试结果以下:(Quartz默认的线程池大小为10)
0 30 20 * * ?0 0/2 * * * ?2017-03-08 18:02:00.025 INFO 5328 --- [eduler_Worker-1] c.c.s.quartz.entity.ScheduleTask : Hello world, i'm the king of the world!!!2017-03-08 18:04:00.003 INFO 5328 --- [eduler_Worker-2] c.c.s.quartz.entity.ScheduleTask : Hello world, i'm the king of the world!!!2017-03-08 18:06:00.002 INFO 5328 --- [eduler_Worker-3] c.c.s.quartz.entity.ScheduleTask : Hello world, i'm the king of the world!!!2017-03-08 18:08:00.002 INFO 5328 --- [eduler_Worker-4] c.c.s.quartz.entity.ScheduleTask : Hello world, i'm the king of the world!!!
从上面的日志打印时间来看,咱们实现了动态配置,最初的时候,任务是天天20:30执行,后面经过动态刷新变成了每隔2分钟执行一次。
虽然上面的解决方案没有使用Quartz推荐的方式完美,但基本上能够知足咱们的需求,固然也能够采用触发事件的方式来实现,例如当前端修改定时任务的触发时间时,异步的向后台发送通知,后台收到通知后,而后再更新程序,也能够实现动态的定时任务刷新
--------------------- 本文来自 牛奋lch 的CSDN 博客 ,全文地址请点击:https://blog.csdn.net/liuchuanhong1/article/details/60873295?utm_source=copy