Scheduler 每次執行,都會根據JobDetail建立一個新的Job例項,這樣就可以規避併發訪問的問題(jobDetail的例項也是新的)
Quzrtz 定時任務預設都是併發執行,不會等待上一次任務執行完畢,只要間隔時間到就會執行,如果定時任務執行太長,會長時間佔用資源,導致其它任務堵塞
@DisallowConcurrentExecution: job類上,禁止併發地執行同一個job定義 (JobDetail定義的)的多個例項。
- scheduler:可以理解為定時任務的工作容器或者說是工作場所,所有定時任務都是放在裡面工作,可以開啟和停止。
- trigger:可以理解為是定時任務任務的工作規則配置,例如說,沒個幾分鐘呼叫一次,或者說指定每天那個時間點執行。
- jobDetail:定時任務的資訊,例如配置定時任務的名字,群組之類的。
- job:定時任務的真正的業務處理邏輯的地方。
簡單示例
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") //設定JOB的名字和組
.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());
}
}
usingJobData
透過 usingJobData 往定時任務中傳遞引數
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"));
}
}
透過 屬性賦值
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") //透過 setName 自動賦值
.build();
Trigger trigger = TriggerBuilder.newTrigger()
.withIdentity("trigger1", "trigger1")
.usingJobData("trigger","trigger.JobDataMap.Value")
.usingJobData("name","trigger.name.Value") //如果 Trigger 有值,會覆蓋 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);
}
}
非併發執行
@DisallowConcurrentExecution job類上,禁止併發地執行同一個job定義 (JobDetail定義的)的多個例項。
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(對 trigger 中的 datamap 無效),如果一個任務不是
import cn.hutool.core.date.DateUtil;
import org.quartz.*;
//持久化JobDetail中的JobDataMap(對 trigger 中的 datamap 無效),如果一個任務不是
@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") //透過 setName 自動賦值
.usingJobData("count",0) //透過 setName 自動賦值
.build();
Trigger trigger = TriggerBuilder.newTrigger()
.withIdentity("trigger1", "trigger1")
.usingJobData("trigger","trigger.JobDataMap.Value")
.usingJobData("name","trigger.name.Value") //如果 Trigger 有值,會覆蓋 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();
}
}
}