java 使用 JDBC JobStore 的 Quartz 调度器

Quartz Scheduler using JDBC JobStore

提问by Sangram Anand

For the first time i stored the jobs and scheduled them using crontrigger with the below code.

我第一次存储作业并使用 crontrigger 和以下代码安排它们。

package com.generalsentiment.test.quartz;

import static org.quartz.CronScheduleBuilder.cronSchedule;
import static org.quartz.JobBuilder.newJob;
import static org.quartz.TriggerBuilder.newTrigger;

import java.util.Date;
import java.util.Properties;

import org.quartz.CronTrigger;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerFactory;
import org.quartz.SchedulerMetaData;
import org.quartz.impl.StdSchedulerFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class CronTriggerExample {

    public void run() throws Exception {
        Logger log = LoggerFactory.getLogger(CronTriggerExample.class);

        System.out.println("------- Initializing -------------------");

        Xml config = new Xml("src/hibernate.cfg.xml", "hibernate-configuration");

        Properties prop = new Properties();
        prop.setProperty("org.quartz.scheduler.instanceName", "ALARM_SCHEDULER");
        prop.setProperty("org.quartz.threadPool.class",   
                        "org.quartz.simpl.SimpleThreadPool");
        prop.setProperty("org.quartz.threadPool.threadCount", "4");

        prop.setProperty("org.quartz.threadPool
                        .threadsInheritContextClassLoaderOfInitializingThread", "true");

        prop.setProperty("org.quartz.jobStore.class", 
                          "org.quartz.impl.jdbcjobstore.JobStoreTX");
        prop.setProperty("org.quartz.jobStore.driverDelegateClass", 
                          "org.quartz.impl.jdbcjobstore.StdJDBCDelegate");
        prop.setProperty("org.quartz.jobStore.dataSource", "tasksDataStore");
        prop.setProperty("org.quartz.jobStore.tablePrefix", "QRTZ_");
        prop.setProperty("org.quartz.jobStore.misfireThreshold", "60000");
        prop.setProperty("org.quartz.jobStore.isClustered", "false");

        prop.setProperty("org.quartz.dataSource.tasksDataStore.driver", 
              config.child("session-factory").children("property").get(1).content());
        prop.setProperty("org.quartz.dataSource.tasksDataStore.URL", config.child("session-
             factory").children("property").get(2).content());
        prop.setProperty("org.quartz.dataSource.tasksDataStore.user", config.child("session-
             factory").children("property").get(3).content());
        prop.setProperty("org.quartz.dataSource.tasksDataStore.password", 
             config.child("session-factory").children("property").get(4).content());
        prop.setProperty("org.quartz.dataSource.tasksDataStore.maxConnections", "20");

        // First we must get a reference to a scheduler
        SchedulerFactory sf = new StdSchedulerFactory(prop);
        Scheduler sched = sf.getScheduler();

        System.out.println("------- Initialization Complete --------");

        System.out.println("------- Scheduling Jobs ----------------");

        // jobs can be scheduled before sched.start() has been called

        // job 1 will run exactly at 12:55 daily
        JobDetail job = newJob(SimpleJob.class).withIdentity("job2", "group2").build();

        CronTrigger trigger = newTrigger().withIdentity("trigger2", "group2")
                                          .withSchedule(cronSchedule("00 15 15 * * 
                                                         ?")).build();

        Date ft = sched.scheduleJob(job, trigger);
        System.out.println(sched.getSchedulerName());
        System.out.println(job.getKey() + " has been scheduled to run at: " + ft
                + " and repeat based on expression: "
                + trigger.getCronExpression());

        System.out.println("------- Starting Scheduler ----------------");

        /*
         * All of the jobs have been added to the scheduler, but none of the
         * jobs will run until the scheduler has been started. If you have
         * multiple jobs performing multiple tasks, then its recommended to
         * write it in separate classes, like SimpleJob.class writes
         * organization members to file.
         */
        sched.start();

        System.out.println("------- Started Scheduler -----------------");

        System.out.println("------- Waiting five minutes... ------------");
        try {
            // wait five minutes to show jobs
            Thread.sleep(300L * 1000L);
            // executing...
        } catch (Exception e) {
        }

        System.out.println("------- Shutting Down ---------------------");

        sched.shutdown(true);

        System.out.println("------- Shutdown Complete -----------------");

        SchedulerMetaData metaData = sched.getMetaData();


        System.out.println("Executed " + metaData.getNumberOfJobsExecuted() + " jobs.");

    }

    public static void main(String[] args) throws Exception {

        CronTriggerExample example = new CronTriggerExample();
        example.run();
    }
    }

And the details are stored in Tables - QRTZ_CRON_TRIGGERS, QRTZ_JOB_DETAILS& QRTZ_TRIGGERS

详细信息存储在 Tables - QRTZ_CRON_TRIGGERS, QRTZ_JOB_DETAILS&QRTZ_TRIGGERS

My doubt is How to schedule the jobs that are stored in DB. How to display the list of jobs in a jsp page & how to trigger them automatically. Ours is a struts2 application with Hibernate3 ORM. I am trying to initialize the quartz scheduler when the application loads. But am unable to.

我的疑问是如何安排存储在数据库中的作业。如何在 jsp 页面中显示作业列表以及如何自动触发它们。我们是一个带有 Hibernate3 ORM 的 struts2 应用程序。我正在尝试在应用程序加载时初始化石英调度程序。但我做不到。

回答by Oluwasegun Idowu

Date ft = sched.scheduleJob(job, trigger);

When this is called, your job would be scheduled for the next fire time. The scheduled job would stored in the appropriate DB tables. To Display the list of jobs on a jsp, you should persist you job key as well as custom description of what your job entails to another DB table so that during retrieval you can retrieve this custom description as well as data Quartz persist into its own tables. Triggering this jobs automatically is something Quartz handles for you. Once the crone expression is set to what is desired and your Job class implements org.quartz.Job, Quartz would run the execute()method at your desired next fire time

当它被调用时，你的工作将被安排在下一个火灾时间。计划的作业将存储在适当的数据库表中。要在 jsp 上显示作业列表，您应该将作业键以及作业需要的自定义描述保存到另一个数据库表中，以便在检索期间您可以检索此自定义描述以及数据 Quartz 保存到它自己的表中. 自动触发这些作业是 Quartz 为您处理的。一旦 crone 表达式设置为所需的并且您的 Job 类实现org.quartz.Job，Quartz 将execute()在您想要的下一次触发时间运行该方法

回答by Abhishek bhutra

JobDetail job = newJob(SimpleJob.class).withIdentity("job2", "group2").build();

this means you will have a class named SimpleJobthat implements org.quartz.Job. In that class execute()method need to be implemented. Job is triggered automatically at the time you specified by cron expression. That execute method is called when job is triggered.

这意味着您将有一个名为SimpleJob实现的类org.quartz.Job。在那个类中execute()需要实现方法。作业在您指定的时间自动触发cron expression。触发作业时调用该 execute 方法。