带你浅谈下Quartz的简单使用

忘是亡心i 2024-03-23 07:29 59阅读 0赞

Scheduler 每次执行，都会根据JobDetail创建一个新的Job实例，这样就可以规避并发访问的问题（jobDetail的实例也是新的）

Quzrtz 定时任务默认都是并发执行，不会等待上一次任务执行完毕，只要间隔时间到就会执行，如果定时任务执行太长，会长时间占用资源，导致其它任务堵塞

@DisallowConcurrentExecution: job类上，禁止并发地执行同一个job定义 (JobDetail定义的)的多个实例。

![4dda5066a616f0b8395ca7a1fd99dafa.png][]

*  scheduler：可以理解为定时任务的工作容器或者说是工作场所，所有定时任务都是放在里面工作，可以开启和停止。
 *  trigger：可以理解为是定时任务任务的工作规则配置，例如说，没个几分钟调用一次，或者说指定每天那个时间点执行。
 *  jobDetail：定时任务的信息，例如配置定时任务的名字，群组之类的。
 *  job：定时任务的真正的业务处理逻辑的地方。

#### 简单示例 ####

TestClient.Java

import org.quartz.*;
    import org.quartz.impl.StdSchedulerFactory;
    
    public class TaskClient {
    
        public static void main(String[] args) {
            JobDetail jobDetail = JobBuilder.newJob(TaskJob.class)
                    .withIdentity("job1", "group1")  //设置JOB的名字和组
                    .build();
    
            Trigger trigger = TriggerBuilder.newTrigger()
                    .withIdentity("trigger1", "trigger1")
                    .startNow()
                    .withSchedule(SimpleScheduleBuilder.simpleSchedule().withIntervalInSeconds(1)
                            .repeatForever())
                    .build();
            try {
                Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();
                scheduler.scheduleJob(jobDetail,trigger);
                scheduler.start();
            } catch (SchedulerException ex) {
                ex.printStackTrace();
            }
    
        }
    
    }

TaskJob.Java

import cn.hutool.core.date.DateUtil;
    import org.quartz.Job;
    import org.quartz.JobExecutionContext;
    import org.quartz.JobExecutionException;
    
    public class TaskJob implements Job {
        @Override
        public void execute(JobExecutionContext jobExecutionContext) throws JobExecutionException {
            System.out.println("TaskJob => " + DateUtil.now());
        }
    }

![ab4159c41e5388a7a097a76fbff35f5a.png][]

#### usingJobData ####

通过 usingJobData 往定时任务中传递参数

import org.quartz.*;
    import org.quartz.impl.StdSchedulerFactory;
    
    public class TaskClient {
    
        public static void main(String[] args) {
            JobDetail jobDetail = JobBuilder.newJob(TaskJob.class)
                    .withIdentity("job1", "group1")
                    .usingJobData("job","jobDetail1.JobDataMap.Value")
                    .build();
    
            Trigger trigger = TriggerBuilder.newTrigger()
                    .withIdentity("trigger1", "trigger1")
                    .usingJobData("trigger","trigger.JobDataMap.Value")
                    .startNow()
                    .withSchedule(SimpleScheduleBuilder.simpleSchedule().withIntervalInSeconds(1)
                            .repeatForever())
                    .build();
            try {
                Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();
                scheduler.scheduleJob(jobDetail,trigger);
                scheduler.start();
            } catch (SchedulerException ex) {
                ex.printStackTrace();
            }
    
        }
    
    }

TaskJob.java

import org.quartz.Job;
    import org.quartz.JobDataMap;
    import org.quartz.JobExecutionContext;
    import org.quartz.JobExecutionException;
    
    public class TaskJob implements Job {
        @Override
        public void execute(JobExecutionContext context) throws JobExecutionException {
            JobDataMap jobDataMap = context.getJobDetail().getJobDataMap();
            JobDataMap triggerMap = context.getTrigger().getJobDataMap();
            JobDataMap mergeMap = context.getMergedJobDataMap();
    
    
            System.out.println("jobDataMap => " + jobDataMap.getString("job"));
            System.out.println("triggerMap => " + triggerMap.getString("trigger"));
            System.out.println("mergeMap => " + mergeMap.getString("trigger"));
        }
    }

![0d13f1b24a6e1090b652ebbd9598b1ca.png][]

通过 属性赋值

import org.quartz.*;
    import org.quartz.impl.StdSchedulerFactory;
    
    public class TaskClient {
    
        public static void main(String[] args) {
            JobDetail jobDetail = JobBuilder.newJob(TaskJob.class)
                    .withIdentity("job1", "group1")
                    .usingJobData("job","jobDetail1.JobDataMap.Value")
                    .usingJobData("name","jobDetail1.name.Value") //通过 setName 自动赋值
                    .build();
    
            Trigger trigger = TriggerBuilder.newTrigger()
                    .withIdentity("trigger1", "trigger1")
                    .usingJobData("trigger","trigger.JobDataMap.Value")
                    .usingJobData("name","trigger.name.Value")  //如果 Trigger 有值，会覆盖 JobDetail
                    .startNow()
                    .withSchedule(SimpleScheduleBuilder.simpleSchedule().withIntervalInSeconds(1)
                            .repeatForever())
                    .build();
            try {
                Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();
                scheduler.scheduleJob(jobDetail,trigger);
                scheduler.start();
            } catch (SchedulerException ex) {
                ex.printStackTrace();
            }
    
        }
    
    }

import org.quartz.*;
    
    public class TaskJob implements Job {
    
        private String name;
    
        public void setName(String name) {
            this.name = name;
        }
    
        @Override
        public void execute(JobExecutionContext context) throws JobExecutionException {
    
            System.out.println("name => " + name);
        }
    }

#### 非并发执行 ####

@DisallowConcurrentExecution job类上，禁止并发地执行同一个job定义 (JobDetail定义的)的多个实例。

import cn.hutool.core.date.DateUtil;
    import org.quartz.*;
    
    @DisallowConcurrentExecution
    public class TaskJob implements Job {
    
        @Override
        public void execute(JobExecutionContext context) {
            System.out.println("Time => " + DateUtil.now());
            try {
                Thread.sleep(3000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

@PersistJobDataAfterExecution  
持久化JobDetail中的JobDataMap（对 trigger 中的 datamap 无效），如果一个任务不是

import cn.hutool.core.date.DateUtil;
    
    import org.quartz.*;
    
    //持久化JobDetail中的JobDataMap（对 trigger 中的 datamap 无效），如果一个任务不是
    @PersistJobDataAfterExecution
    public class TaskJob implements Job {
    
        @Override
        public void execute(JobExecutionContext context) {
            JobDataMap triggerMap = context.getJobDetail().getJobDataMap();
            triggerMap.put("count", triggerMap.getInt("count") + 1);
            System.out.println("Time => " + DateUtil.now() + " count =>" + triggerMap.getInt("count"));
    
        }
    }

Client

import org.quartz.*;
    import org.quartz.impl.StdSchedulerFactory;
    
    public class TaskClient {
    
        public static void main(String[] args) {
            JobDetail jobDetail = JobBuilder.newJob(TaskJob.class)
                    .withIdentity("job1", "group1")
                    .usingJobData("job","jobDetail1.JobDataMap.Value")
                    .usingJobData("name","jobDetail1.name.Value") //通过 setName 自动赋值
                    .usingJobData("count",0) //通过 setName 自动赋值
                    .build();
    
            Trigger trigger = TriggerBuilder.newTrigger()
                    .withIdentity("trigger1", "trigger1")
                    .usingJobData("trigger","trigger.JobDataMap.Value")
                    .usingJobData("name","trigger.name.Value")  //如果 Trigger 有值，会覆盖 JobDetail
                    .startNow()
                    .withSchedule(SimpleScheduleBuilder.simpleSchedule().withIntervalInSeconds(1)
                            .repeatForever())
                    .build();
            try {
                Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();
                scheduler.scheduleJob(jobDetail,trigger);
                scheduler.start();
            } catch (SchedulerException ex) {
                ex.printStackTrace();
            }
    
        }
    
    }

[4dda5066a616f0b8395ca7a1fd99dafa.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/23/8b67df4838cf4fc6b34f1c7128b86ffd.png
[ab4159c41e5388a7a097a76fbff35f5a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/23/e99c8fe8eb2048769d0786da2fb964bf.png
[0d13f1b24a6e1090b652ebbd9598b1ca.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/23/648b308dd8ec41f9ad118ad927703223.png