前言前端
在咱們平常的開發中,不少時候,定時任務都不是寫死的,而是寫到數據庫中,從而實現定時任務的動態配置,下面就經過一個簡單的示例,來實現這個功能。java
1、新建一個springboot工程,並添加依賴spring
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency><!-- 爲了方便測試,此處使用了內存數據庫 --> <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><!-- 該依賴必加,裏面有sping對schedule的支持 --><groupId>org.springframework</groupId><artifactId>spring-context-support</artifactId></dependency>
2、配置文件application.propertiessql
# 服務器端口號server.port=7902# 是否生成ddl語句spring.jpa.generate-ddl=false # 是否打印sql語句spring.jpa.show-sql=true # 自動生成ddl,因爲指定了具體的ddl,此處設置爲nonespring.jpa.hibernate.ddl-auto=none# 使用H2數據庫spring.datasource.platform=h2# 指定生成數據庫的schema文件位置spring.datasource.schema=classpath:schema.sql# 指定插入數據庫語句的腳本位置spring.datasource.data=classpath:data.sql# 配置日誌打印信息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類數據庫
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; }……此處省略getter和setter方法……}
4、任務類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 // 此註解必加@EnableScheduling // 此註解必加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配置類springboot
因爲springboot追求零xml配置,因此下面會以配置Bean的方式來實現服務器
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:配置定時任務 */ @Bean(name = "jobDetail") public MethodInvokingJobDetailFactoryBean detailFactoryBean(ScheduleTask task) {// ScheduleTask爲須要執行的任務 MethodInvokingJobDetailFactoryBean jobDetail = new MethodInvokingJobDetailFactoryBean(); /* * 是否併發執行 * 例如每5s執行一次任務,可是當前任務尚未執行完,就已通過了5s了, * 若是此處爲true,則下一個任務會執行,若是此處爲false,則下一個任務會等待上一個任務執行完後,再開始執行 */ jobDetail.setConcurrent(false); jobDetail.setName("srd-chhliu");// 設置任務的名字 jobDetail.setGroup("srd");// 設置任務的分組,這些屬性均可以存儲在數據庫中,在多任務的時候使用 /* * 爲須要執行的實體類對應的對象 */ jobDetail.setTargetObject(task); /* * sayHello爲須要執行的方法 * 經過這幾個配置,告訴JobDetailFactoryBean咱們須要執行定時執行ScheduleTask類中的sayHello方法 */ jobDetail.setTargetMethod("sayHello"); return jobDetail; } /** * attention: * Details:配置定時任務的觸發器,也就是何時觸發執行定時任務 */ @Bean(name = "jobTrigger") public CronTriggerFactoryBean cronJobTrigger(MethodInvokingJobDetailFactoryBean jobDetail) { CronTriggerFactoryBean tigger = new CronTriggerFactoryBean(); tigger.setJobDetail(jobDetail.getObject()); tigger.setCronExpression("0 30 20 * * ?");// 初始時的cron表達式 tigger.setName("srd-chhliu");// trigger的name return tigger; } /** * attention: * Details:定義quartz調度工廠 */ @Bean(name = "scheduler") public SchedulerFactoryBean schedulerFactory(Trigger cronJobTrigger) { SchedulerFactoryBean bean = new SchedulerFactoryBean(); // 用於quartz集羣,QuartzScheduler 啓動時更新己存在的Job bean.setOverwriteExistingJobs(true); // 延時啓動,應用啓動1秒後 bean.setStartupDelay(1); // 註冊觸發器 bean.setTriggers(cronJobTrigger); return bean; }}
6、定時查庫,並更新任務併發
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查庫,並根據查詢結果決定是否從新設置定時任務 public void scheduleUpdateCronTrigger() throws SchedulerException { CronTrigger trigger = (CronTrigger) scheduler.getTrigger(cronTrigger.getKey()); String currentCron = trigger.getCronExpression();// 當前Trigger使用的 String searchCron = repository.findOne(1L).getCron();// 從數據庫查詢出來的 System.out.println(currentCron); System.out.println(searchCron); if (currentCron.equals(searchCron)) { // 若是當前使用的cron表達式和從數據庫中查詢出來的cron表達式一致,則不刷新任務 } else { // 表達式調度構建器 CronScheduleBuilder scheduleBuilder = CronScheduleBuilder.cronSchedule(searchCron); // 按新的cronExpression表達式從新構建trigger trigger = (CronTrigger) scheduler.getTrigger(cronTrigger.getKey()); trigger = trigger.getTriggerBuilder().withIdentity(cronTrigger.getKey()) .withSchedule(scheduleBuilder).build(); // 按新的trigger從新設置job執行 scheduler.rescheduleJob(cronTrigger.getKey(), trigger); currentCron = searchCron; } }}
6、相關腳本app
一、data.sql
insert into config(id,cron) values(1,'0 0/2 * * * ?'); # 每2分鐘執行一次定時任務
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、運行測試
測試結果以下:(Quartz默認的線程池大小爲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!!!
從上面的日誌打印時間來看,咱們實現了動態配置,最初的時候,任務是天天20:30執行,後面經過動態刷新變成了每隔2分鐘執行一次。
雖然上面的解決方案沒有使用Quartz推薦的方式完美,但基本上能夠知足咱們的需求,固然也能夠採用觸發事件的方式來實現,例如當前端修改定時任務的觸發時間時,異步的向後臺發送通知,後臺收到通知後,而後再更新程序,也能夠實現動態的定時任務刷新
--------------------- 本文來自 牛奮lch 的CSDN 博客 ,全文地址請點擊:https://blog.csdn.net/liuchuanhong1/article/details/60873295?utm_source=copy