作业调度---quartz

  作业调度是现代系统中对 Java 应用程序的一般要求，而且也是对 Java 开发人员一贯的要求。
  作业调度最合适的解决方案就是来自 OpenSymphony 的 Quartz API。

  Quartz 允许开发人员根据时间间隔（或天）来调度作业，Quartz将作业和触发器分开，这样可以方便二者的自由组合，形成多对多的关系。其中作业，是指能够调度执行的任务，而触发器是指对作业的调度，包括对时间的安排等。

   Quartz的HelloWord： 

   1.环境：quartz-1.6.6 过程中需引入 quartz-1.6.6.jar和 commons-logging-1.1.jar（在下下来的官方包中有，后者在lib/core包中）

   2.作业的编写 implements Job

import java.util.Date;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.quartz.Job;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;


public class HelloJob implements Job {

    private static Log _log = LogFactory.getLog(HelloJob.class);

    public HelloJob() {
    }
    
    public void execute(JobExecutionContext context)
        throws JobExecutionException {

        // Say Hello to the World and display the date/time
        _log.info("Hello World! - " + new Date());
    }

}

    解释：在 execute 方法接受一个 JobExecutionContext 对象作为参数。这个对象提供了作业实例的运行时上下文

 

 

 

    2.触发器的编写 

 

package example1;

import java.util.Date;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerFactory;
import org.quartz.SimpleTrigger;
import org.quartz.TriggerUtils;
import org.quartz.impl.StdSchedulerFactory;


/**
 * 
 * 作业调度理解：
 * 1.初始化： 从调度工厂中取出调度器
 * 2.调度作业：创建作业和触发器，并装配在一起
 * 3.启动
 * 4.关闭
 */
public class SimpleExample {

    
    public void run() throws Exception {
        Log log = LogFactory.getLog(SimpleExample.class);

        log.info("------- Initializing ----------------------");

        SchedulerFactory sf = new StdSchedulerFactory();
        Scheduler sched = sf.getScheduler();

        log.info("------- Initialization Complete -----------");

        log.info("------- Scheduling Jobs -------------------");

        // computer a time that is on the next round minute
        Date runTime = TriggerUtils.getEvenMinuteDate(new Date());

        // define the job and tie it to our HelloJob class
        JobDetail job = new JobDetail("job1", "group1", HelloJob.class);
        
        // Trigger the job to run on the next round minute
        SimpleTrigger trigger = 
            new SimpleTrigger("trigger1", "group1", runTime);
        
        // Tell quartz to schedule the job using our trigger
        sched.scheduleJob(job, trigger);
        log.info(job.getFullName() + " will run at: " + runTime); 
        
        log.info("------- Started Scheduler -----------------");
        sched.start();
        
        log.info("------- Waiting 90 seconds... -------------");
        try {
            // wait 90 seconds to show jobs
            Thread.sleep(90L * 1000L); 
        } catch (Exception e) {
        }

        log.info("------- Shutting Down ---------------------");
        sched.shutdown(true);
        log.info("------- Shutdown Complete -----------------");
    }

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

        SimpleExample example = new SimpleExample();
        example.run();

    }

}

 

 

 

   解释：JobDetail：JobDetail 对象储存作业的侦听器、群组、数据映射、描述以及作业的其他属性，是作业状态的存储

     以上完成了QuartzHelloWord的编写，对Quartz有了初步的印象，下面对触发器进行点探讨。

     CronTrigger 支持类似日历的重复间隔，而不是单一的时间间隔.

    Cron 表达式包括以下 7 个字段：

–   秒（0-59）

–   分（0-59）

–   小时（0-23）

–   每月第几天（1-31）

–   月（1-12或JAN-DEC）

–   每星期第几天（1-7或SUN-SAT）

–   年（1970-2099）

•  特殊字符

–

–  " /"--表示增量值。例如，在秒字段中“5/15”代表从第 5 秒开始，每 15 秒一次

其中「每月第几天」与「每星期第几天」是互斥的，两个只能设定一个，不设定的以 ? 符号代替，如果有好几个时间点，可以使用 , 符号，例如：「0 0 10,12,14 * * ?」表示每天的10时、12时、14时要执行Job

    "-"--表连续 ，例如「0 0 10,12,14 1-15 * ?」表示每月的1到15日每10时、12时、14时要执行Job，时间格式中的年指定可有可无，例如：「0 0 10,12,14 ? * MON 2006」表示2006年每星期一的10时、12时、14时要执行Job。

   "?"--可以理解为只是站位的意思，只有在月内日期和周内日期字段中可用，如果指定月内日期，可以在周内日期字段中插入“?”，表示周内日期值无关紧要

    "L"(last)--只有在月内日期和周内日期字段中可用,放在月内日期字段中，表示安排在当月最后一天执行;在周内日期字段中，如果“L”单独存在，就等于“7”，否则代表当月内周内日期的最后一个实例。所以“0L”表示安排在当月的最后一个星期日执行。

   "w"--执行安排在最靠近指定值的工作日。把“1W”放在月内日期字段中，表示把执行安排在当月的第一个工作日内。

   "#”--给定月份指定具体的工作日实例。把“MON#2”放在周内日期字段中，表示把任务安排在当月的第二个星期一

    "*"--任意

  具体例子：

import java.util.Date;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
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;

public class CronTriggerExample {


    public void run() throws Exception {
        Log log = LogFactory.getLog(CronTriggerExample.class);

        log.info("------- Initializing -------------------");

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

        log.info("------- Initialization Complete --------");

        log.info("------- Scheduling Jobs ----------------");

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

        // job 1 will run every 20 seconds
        JobDetail job = new JobDetail("job1", "group1", SimpleJob.class);
        CronTrigger trigger = new CronTrigger("trigger1", "group1", "job1",
                "group1", "0/5 * * * * ?");
        sched.addJob(job, true);
        Date ft = sched.scheduleJob(trigger);
        log.info(job.getFullName() + " has been scheduled to run at: " + ft
                + " and repeat based on expression: "
                + trigger.getCronExpression());

        // job 2 will run every other minute (at 15 seconds past the minute)
        job = new JobDetail("job2", "group1", SimpleJob.class);
        trigger = new CronTrigger("trigger2", "group1", "job2", "group1",
                "15 0/2 * * * ?");
        sched.addJob(job, true);
        ft = sched.scheduleJob(trigger);
        log.info(job.getFullName() + " has been scheduled to run at: " + ft
                + " and repeat based on expression: "
                + trigger.getCronExpression());

        // job 3 will run every other minute but only between 8am and 5pm
        job = new JobDetail("job3", "group1", SimpleJob.class);
        trigger = new CronTrigger("trigger3", "group1", "job3", "group1",
                "0 0/2 8-17 * * ?");
        sched.addJob(job, true);
        ft = sched.scheduleJob(trigger);
        log.info(job.getFullName() + " has been scheduled to run at: " + ft
                + " and repeat based on expression: "
                + trigger.getCronExpression());

        // job 4 will run every three minutes but only between 5pm and 11pm
        job = new JobDetail("job4", "group1", SimpleJob.class);
        trigger = new CronTrigger("trigger4", "group1", "job4", "group1",
                "0 0/3 17-23 * * ?");
        sched.addJob(job, true);
        ft = sched.scheduleJob(trigger);
        log.info(job.getFullName() + " has been scheduled to run at: " + ft
                + " and repeat based on expression: "
                + trigger.getCronExpression());

        // job 5 will run at 10am on the 1st and 15th days of the month
        job = new JobDetail("job5", "group1", SimpleJob.class);
        trigger = new CronTrigger("trigger5", "group1", "job5", "group1",
                "0 0 10am 1,15 * ?");
        sched.addJob(job, true);
        ft = sched.scheduleJob(trigger);
        log.info(job.getFullName() + " has been scheduled to run at: " + ft
                + " and repeat based on expression: "
                + trigger.getCronExpression());

        // job 6 will run every 30 seconds but only on Weekdays (Monday through
        // Friday)
        job = new JobDetail("job6", "group1", SimpleJob.class);
        trigger = new CronTrigger("trigger6", "group1", "job6", "group1",
                "0,30 * * ? * MON-FRI");
        sched.addJob(job, true);
        ft = sched.scheduleJob(trigger);
        log.info(job.getFullName() + " has been scheduled to run at: " + ft
                + " and repeat based on expression: "
                + trigger.getCronExpression());

        // job 7 will run every 30 seconds but only on Weekends (Saturday and
        // Sunday)
        job = new JobDetail("job7", "group1", SimpleJob.class);
        trigger = new CronTrigger("trigger7", "group1", "job7", "group1",
                "0,30 * * ? * SAT,SUN");
        sched.addJob(job, true);
        ft = sched.scheduleJob(trigger);
        log.info(job.getFullName() + " has been scheduled to run at: " + ft
                + " and repeat based on expression: "
                + trigger.getCronExpression());

        log.info("------- Starting Scheduler ----------------");
        sched.start();

        log.info("------- Started Scheduler -----------------");

        log.info("------- Waiting five minutes... ------------");
        try {
            Thread.sleep(300L * 1000L);
        } catch (Exception e) {
        }

        log.info("------- Shutting Down ---------------------");

        sched.shutdown(true);

        log.info("------- Shutdown Complete -----------------");

        SchedulerMetaData metaData = sched.getMetaData();
        log.info("Executed " + metaData.numJobsExecuted() + " jobs.");

    }

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

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

}