Springboot中spring-boot-starter-quartz的使用及说明

这篇文章主要介绍了Springboot中spring-boot-starter-quartz的使用及说明，具有很好的参考价值，希望对大家有所帮助。如有错误或未考虑完全的地方，望不吝赐教

前言

在做定时任务时，有需求是把定时执行cron表达式存在数据库中，通过更改数据库中的值，来改变任务执行的频率。

一、添加pom.xml依赖

 org.springframework.bootspring-boot-starter-quartz org.mybatis.spring.bootmybatis-spring-boot-starter1.3.2 mysqlmysql-connector-java8.0.13runtime

二、application.properties添加数据库信息

spring.datasource.url:jdbc:mysql://localhost:3306/test?setUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false spring.datasource.username:root spring.datasource.password:root

三、数据库操作

1.创建数据库test和表cron

SET NAMES utf8mb4; SET FOREIGN_KEY_CHECKS = 0; -- ---------------------------- -- Table structure for cron -- ---------------------------- DROP TABLE IF EXISTS `cron`; CREATE TABLE `cron`  ( `id` int NOT NULL AUTO_INCREMENT, `cron` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL, PRIMARY KEY (`id`) USING BTREE ) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic; -- ---------------------------- -- Records of cron -- ---------------------------- INSERT INTO `cron` VALUES (1, '0/5 * * * * ? *');

cron表：

cron表

2.创建cron表对应的实体类

public class CronModel { private String cron; public String getCron() { return cron; } public void setCron(String cron) { this.cron = cron; } }

3.创建Mapper

@Mapper public interface CronModelMapper { @Select("select cron from cron where id = 1") String getCron(); }

4.创建Service

@Service public class CronModelService { @Autowired CronModelMapper cronModelMapper; public String getCron() { return cronModelMapper.getCron(); } }

二、Quartz相关

1.创建JobConfig类

/** * Quartz的相关配置，注册JobDetail和Trigger * 注意JobDetail和Trigger是org.quartz包下的，不是spring包下的，不要导入错误 */ @Configuration public class JobConfig { @Autowired CronModelService cronModelService; @Bean public JobDetail jobDetail() { JobDetail jobDetail = JobBuilder.newJob(Job.class) .withIdentity("jobDetail", "jobDetail") .storeDurably() .build(); return jobDetail; } @Bean public Trigger trigger() { Trigger trigger = TriggerBuilder.newTrigger() .forJob(jobDetail()) .withIdentity("trigger", "trigger") .startNow() // 每天0点执行 .withSchedule(CronScheduleBuilder.cronSchedule(cronModelService.getCron())) .build(); return trigger; } }

2.创建Job类

@Component public class Job extends QuartzJobBean { Logger logger = LoggerFactory.getLogger(Job.class); @Autowired CronModelService cronModelService; @Autowired private Scheduler scheduler; @Override protected void executeInternal(JobExecutionContext jobExecutionContext) { logger.info("执行"); Trigger trigger = jobExecutionContext.getTrigger(); String cron = cronModelService.getCron(); try { CronTrigger cronTrigger = (CronTrigger) scheduler.getTrigger(trigger.getKey()); String cronExpression = cronTrigger.getCronExpression(); if (!cron.equals(cronExpression)) { //创建表达式调度器 CronScheduleBuilder cronSchedule = CronScheduleBuilder.cronSchedule(cron); //重构 cronTrigger = cronTrigger.getTriggerBuilder() .withIdentity(trigger.getKey()) .withSchedule(cronSchedule) .build(); scheduler.rescheduleJob(trigger.getKey(), cronTrigger); } } catch (SchedulerException e) { e.printStackTrace(); } } }