Java示例：使用Quartz进行动态作业调度

Question

我希望提供一个用户界面来动态定义Quartz JOBs。用户可以定义JOB的属性，如JOB名称、cron表达式或时间间隔、任务的特定java类等。

是否有任何开源项目可提供此功能？或者，如果我想创建自己的动态Quartz Scheduler模块，应该怎么做？

- Narendra Verma

Answer 1

动态Quartz JOB调度的示例代码：

Maven依赖项

         <dependency>
            <groupId>org.quartz-scheduler</groupId>
            <artifactId>quartz</artifactId>
            <version>1.8.5</version>
         </dependency>
            <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>

应用程序上下文文件 (dynamic-jobs.xml)

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="
            http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
            http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
            http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
            http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd
            http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
            http://www.springmodules.org/schema/ehcache http://www.springmodules.org/schema/cache/springmodules-ehcache.xsd">


    <!-- The Task Bean-->
    <bean id="myTask" class="com.xxx.example.dynamicjob.MyTask" />

    <!-- The quartz scheduler configuration -->
    <bean id="scheduler" class="org.springframework.scheduling.quartz.SchedulerFactoryBean"/>

</beans>

任务的Java类

package com.xxx.example.dynamicjob;

    public class MyTask
    {
        public void performAction() {
            System.out.println("Hey, you reached me...:)");
        }          
    }

创建动态作业的Java类

package com.xxx.example.dynamicjob;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.ClassPathResource;
import org.springframework.scheduling.quartz.CronTriggerBean;
import org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean;

public class DynamicJobExample {

    /**
    * @param args
    */
    public static void main(String[] args) {

                ClassPathResource res = new ClassPathResource("dynamic-jobs.xml");
                XmlBeanFactory factory = new XmlBeanFactory(res);

                //get the quartzFactory bean
                Scheduler scheduler = (Scheduler) factory.getBean("scheduler");

                //get the task bean
                MyTask myTask = (MyTask) factory.getBean("myTask");

                try {
                // create JOB
                MethodInvokingJobDetailFactoryBean jobDetail = new MethodInvokingJobDetailFactoryBean();
                jobDetail.setTargetObject(myTask);
                jobDetail.setTargetMethod("performAction");
                jobDetail.setName("MyJobDetail");
                jobDetail.setConcurrent(false);
                jobDetail.afterPropertiesSet();

                /* SimpleTriggerBean trigger = new SimpleTriggerBean();
                trigger.setBeanName("MyTrigger");
                trigger.setJobDetail((JobDetail) jobDetail.getObject());
                trigger.setRepeatInterval(5000);
                trigger.afterPropertiesSet();
                */

                // create CRON Trigger
                CronTriggerBean cronTrigger = new CronTriggerBean();
                cronTrigger.setBeanName("CRON0001");

                // Execute after each 5 second
                String expression = "5 * * * * ?";
                cronTrigger.setCronExpression(expression);
                cronTrigger.afterPropertiesSet();

                //scheduler.scheduleJob(jobDetail, cronTrigger);

                scheduler.scheduleJob((JobDetail) jobDetail.getObject(), cronTrigger);

                // Start Scheduler        
                scheduler.start();

                } catch (Exception e) {                      
                    e.printStackTrace();
                } 
    }
}

- Narendra Verma

---

以上代码总是给我一个异常"org.quartz.SchedulerException: Trigger cannot be null"，有没有其他的方法..?? - Rajesh

Answer 2

使用Spring 4而不会遇到任何问题（Quartz 2.0） - spring-dispatcher-servlet.xml

<task:annotation-driven executor="myExecutor" scheduler="myScheduler"/>
<task:scheduler id="myScheduler" pool-size="10"/>
<task:executor id="myExecutor" pool-size="1"/>

将上述创建的bean注入Spring bean或Service类中

@Service
public class DynamicJobExample {

@Autowired
@Qualifier("myScheduler")
private TaskScheduler scheduler;

public void schedule() throws ParseException {
    scheduler.schedule(new MyTask(), new CronTrigger("5 * * * * ?"));
  }
}

我的任务应该是一个可运行的类

public class MyTask implements Runnable{

@Override
public void run() {
    System.out.println("Hey, you reached me...:)");
  }
}

Maven的依赖关系（pom.xml）

<spring.version>4.1.0.RELEASE</spring.version>

   <dependency>
        <groupId>org.quartz-scheduler</groupId>
        <artifactId>quartz</artifactId>
        <version>2.2.1</version>
    </dependency>

- Munish Chandel

---

创建我的bean时，我遇到了异常“java.lang.IllegalArgumentException: Start time cannot be null”，你有什么想法吗？ - prageeth

这对于从数据库存储的cron重新调度非常有用。不过我认为XML缺少<task:executor id="myExecutor" pool-size="1"/>。 - Tom Chamberlain

你没有使用Quartz，而是使用了线程池。 - laffuste

这是如何使用Quartz的？ - Cris Pinto

Answer 3

你也可以通过以下方式创建JobDetail和Trigger对象：

JobDetail jobDetail;
String myJobClass = "com.MyJobClass";
String myJobName = "myJobName";
String myJobGroup ="myJobGroup";
Class myJobClassType= Class.forName(myJobClass);            
jobDetail =JobBuilder.newJob().ofType(myJobClassType)
.withIdentity(myJobName, myJobGroup).build();


String myGroup = "myGroup";
String name = "TriggerName";
String expresion = "5 * * * * ?";


Trigger trigger = TriggerBuilder
.newTrigger()
.withIdentity(name, myGroup)
.withSchedule(
CronScheduleBuilder.cronSchedule(expresion))
.build();

- omcartagena

Answer 4

package com.myproject;

import java.text.ParseException;

import org.quartz.JobBuilder;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.SchedulerFactory;
import org.quartz.impl.triggers.CronTriggerImpl;
import org.springframework.stereotype.Component;

@Component
public class QuartzSchedulerExample {
    public QuartzSchedulerExample() {
        SchedulerFactory schedFact = new org.quartz.impl.StdSchedulerFactory();
        Scheduler scheduler;
        try {
            scheduler = schedFact.getScheduler();
            JobDetail details = JobBuilder.newJob(MyMailBean.class)
                    .withDescription("something")
                    .withIdentity("mejob","myGroup")
                    .storeDurably(true).build();

            CronTriggerImpl trigger = new CronTriggerImpl();
            trigger.setName("T1");

            try {
                trigger.setCronExpression("0 0 0 * * ? *");
            } catch (ParseException e) {
                e.printStackTrace();
            }
            trigger.setDescription("desc");
            scheduler.scheduleJob(details,trigger);
            scheduler.start();
        } catch (SchedulerException e) {
            e.printStackTrace();
        }
    }
}

该任务将在每天的00:00:00（小时:分钟:秒）运行

- zawhtut

Answer 5

我有一个类似的问题，我想在quartz（2.3.2版本）的JOB_DETAILS表中更新cron表达式。 情况是这样的，我已经有一个预定的作业正在运行，我想更新它并以不同的频率运行它。 其他的事情我都处理好了，但是表格上的更新不会发生。所以在阅读文档后，我发现可以使用add方法更新作业的详细信息。

// store, and set overwrite flag to 'true'
scheduler.addJob(jobDetail, true);

我所做的事情只涉及Java。

- Atul