五、淺談Trigger

Trigger是什麼

Quartz中的觸發器用來告訴排程程式作業什麼時候觸發
即Trigger物件是用來觸發執行Job的

Quartz框架中的Trigger示意圖

觸發器通用屬性

• JobKey：表示job例項的標識，觸發器被觸發時，該指定的job例項會執行；
• StartTime：表示觸發器的時間表首次被觸發的時間，它的值的型別是Java.util.Date；
• EndTime：指定觸發器的不再被觸發的時間，它的值的型別是Java.util.Date。

程式碼演示

HelloJob類改造

package helloquartz.three;

import
 
 java.text.SimpleDateFormat;
import java.util.Date;

import org.quartz.Job;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
import org.quartz.JobKey;
import org.quartz.Trigger;

/**
 * 自定義任務 觸發器通用屬性
 */
public class HelloJob implements Job {

    @Override
    public void
 
 execute(JobExecutionContext context) throws JobExecutionException {
        // 列印當前的執行時間，格式為2017-01-01 00:00:00
        Date date = new Date();
        SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        System.out.println("--------Current Exec Time Is : " + sf.format(date));

        Trigger currentTrigger = context.getTrigger();
        System.out.println("--------Start Time Is : "
 
 + sf.format(currentTrigger.getStartTime()));
        System.out.println("--------End Time Is : " + sf.format(currentTrigger.getEndTime()));

        JobKey jobKey = currentTrigger.getJobKey();
        System.out.println("--------JobKey info : " + " jobName : " + jobKey.getName() + " jobGroup : " + jobKey.getGroup());
    }
}

HelloScheduler類改造

package helloquartz.three;

import java.text.SimpleDateFormat;
import java.util.Date;

import org.quartz.JobBuilder;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.SchedulerFactory;
import org.quartz.SimpleScheduleBuilder;
import org.quartz.Trigger;
import org.quartz.TriggerBuilder;
import org.quartz.impl.StdSchedulerFactory;

/**
 * 任務排程類  觸發器通用屬性
 */
public class HelloScheduler {

    public static void main(String[] args) throws SchedulerException {
        // 列印當前的執行時間，格式為2017-01-01 00:00:00
        Date date = new Date();
        SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        System.out.println("--------Current Time Is : " + sf.format(date));

        // 建立一個 JobDetail 例項，將該例項與 HelloJob 例項繫結
        JobDetail jobDeatil = JobBuilder.newJob(HelloJob.class)
                .withIdentity("myjob", "jobgroup1")// 定義識別符號
                .build();

        // 獲取距離當前時間3秒後的時間
        date.setTime(date.getTime() + 3000);
        // 獲取距離當前時間6秒後的時間
        Date endDate = new Date();
        endDate.setTime(endDate.getTime() + 6000);

        // 建立一個 Trigger 例項，定義該 job 立即執行，並且每隔兩秒重複執行一次，直到永遠
        Trigger trigger = TriggerBuilder.newTrigger()
                .withIdentity("myTrigger","trigroup1")// 定義識別符號
                .startAt(date)// 定義3秒後執行
                .endAt(endDate)// 定義6秒後結束
                .withSchedule(SimpleScheduleBuilder
                        .simpleSchedule()
                        .withIntervalInSeconds(2)
                        .repeatForever())// 定義執行頻度
                .build();

        // 建立 Scheduler 例項
        SchedulerFactory sfact = new StdSchedulerFactory();
        Scheduler scheduler = sfact.getScheduler();

        // 繫結 JobDetail 和 trigger
        scheduler.scheduleJob(jobDeatil, trigger);

        // 執行任務
        scheduler.start();
    }
}

執行結果：

--------Current Time Is : 2018-03-06 19:48:21
2018-03-06 19:48:21,574 [INFO ][main] Using default implementation for ThreadExecutor  (org.quartz.impl.StdSchedulerFactory:StdSchedulerFactory.java:1172) 
2018-03-06 19:48:21,578 [INFO ][main] Job execution threads will use class loader of thread: main  (org.quartz.simpl.SimpleThreadPool:SimpleThreadPool.java:268) 
2018-03-06 19:48:21,592 [INFO ][main] Initialized Scheduler Signaller of type: class org.quartz.core.SchedulerSignalerImpl  (org.quartz.core.SchedulerSignalerImpl:SchedulerSignalerImpl.java:61) 
2018-03-06 19:48:21,592 [INFO ][main] Quartz Scheduler v.2.2.3 created.  (org.quartz.core.QuartzScheduler:QuartzScheduler.java:240) 
2018-03-06 19:48:21,593 [INFO ][main] RAMJobStore initialized.  (org.quartz.simpl.RAMJobStore:RAMJobStore.java:155) 
2018-03-06 19:48:21,593 [INFO ][main] Scheduler meta-data: Quartz Scheduler (v2.2.3) 'DefaultQuartzScheduler' with instanceId 'NON_CLUSTERED'
  Scheduler class: 'org.quartz.core.QuartzScheduler' - running locally.
  NOT STARTED.
  Currently in standby mode.
  Number of jobs executed: 0
  Using thread pool 'org.quartz.simpl.SimpleThreadPool' - with 10 threads.
  Using job-store 'org.quartz.simpl.RAMJobStore' - which does not support persistence. and is not clustered.
  (org.quartz.core.QuartzScheduler:QuartzScheduler.java:305) 
2018-03-06 19:48:21,593 [INFO ][main] Quartz scheduler 'DefaultQuartzScheduler' initialized from default resource file in Quartz package: 'quartz.properties'  (org.quartz.impl.StdSchedulerFactory:StdSchedulerFactory.java:1327) 
2018-03-06 19:48:21,593 [INFO ][main] Quartz scheduler version: 2.2.3  (org.quartz.impl.StdSchedulerFactory:StdSchedulerFactory.java:1331) 
2018-03-06 19:48:21,594 [INFO ][main] Scheduler DefaultQuartzScheduler_$_NON_CLUSTERED started.  (org.quartz.core.QuartzScheduler:QuartzScheduler.java:575) 
--------Current Exec Time Is : 2018-03-06 19:48:24
--------Start Time Is : 2018-03-06 19:48:24
--------End Time Is : 2018-03-06 19:48:27
--------JobKey info :  jobName : myjob jobGroup : jobgroup1
--------Current Exec Time Is : 2018-03-06 19:48:26
--------Start Time Is : 2018-03-06 19:48:24
--------End Time Is : 2018-03-06 19:48:27
--------JobKey info :  jobName : myjob jobGroup : jobgroup1