Springboot中spring-boot-starter-quartz的使用及说明
作者：AlphaSZH
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
<!--定时器依赖-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-quartz</artifactId>
</dependency>
<!--mybatis插件-->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<!--数据库连接插件-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.13</version>
<scope>runtime</scope>
</dependency>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：
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();
}
}
}总结
和之前引入quartz包(参考Quartz文档)不同之处在于，之前是要先定义好Job和Trigger，然后通过Scheduler去绑定他们，最后去执行start来开启定时任务。
而spring-boot-starter-quartz则省去了Job和Trigger的手动绑定（参考链接: SpringBoot官方文档），也就是做好2.1配置即可。
以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。