【quartz学习笔记】JobExecutionContext和JobDataMap

1.JobExecutionContext

        当Schuduler调用一个Job时，就会将JobExecutionContext传递给Job的execute()方法，同时Job类可以通过JobExecutionConext对象访问到quartz框架运行的环境以及Job实例本的一些属性参数。

JobExecutionContext接口结构

2.JobDataMap

   类结构图

即JobDataMap实现了Map接口，JobDataMap储存在JobExecutionContext中，即使用时通过Job'ExecutionContext获取。主要用途时给Job实例传参。

3.代码实践

MyJob类

import org.quartz.*;
import java.text.SimpleDateFormat;
import java.util.Date;
public class MyJob implements Job {
    public void execute(JobExecutionContext context) throws JobExecutionException {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
        System.out.println("当前时间："+ simpleDateFormat.format(new Date()));
        JobKey jobKey = context.getJobDetail().getKey();
        //获取jobDetail的属性值
        System.out.println("JobDetailName：" + jobKey.getName() +"   JobDetailGroup:" +jobKey.getGroup());
        TriggerKey triggerKey = context.getTrigger().getKey();
        //获取Trigger的属性值
        System.out.println("TriggerName：" + triggerKey.getName() + "   TriggerGroup：" + triggerKey.getGroup());
        //获取JobDetail通过JobDataMap传递的值
        JobDataMap jobDataMap = context.getJobDetail().getJobDataMap();
        String jobDetailParam = jobDataMap.getString("message");
        System.out.println("jobDetailParam:" + jobDetailParam);
        //获取Trigger通过JobDataMap传递的值
        JobDataMap triggerDateMap = context.getTrigger().getJobDataMap();
        String triggerParam = triggerDateMap.getString("message");
        System.out.println("tiggerParam：" + triggerParam);
    }
}

QuartzTest类

import org.quartz.*;
import org.quartz.impl.StdSchedulerFactory;
public class QuartzTest {
    public static void main(String[] args){
        try {
            //定义一个任务
            JobDetail jobDetail = JobBuilder
                    .newJob(MyJob.class)
                    .withIdentity("myJobName","myJobGroup")
                    //通过usingJobData传参给Job
                    .usingJobData("message","This is a param from JobDetail message!")
                    .build();
            Trigger trigger = TriggerBuilder
                    .newTrigger()
                    .withIdentity("myTriggerName","myTriigerGroup")
                    .withDescription("This is a Trigger !")
                    .usingJobData("message","This a param from Trigger message!")
                    .withSchedule(SimpleScheduleBuilder
                            .simpleSchedule()
                            //每五秒重复一次
                            .withIntervalInSeconds(5)
                            .repeatForever())
                    .build();
            //获取scheduler
            Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();
            //将trigger和jobDetail加入到调度
            scheduler.scheduleJob(jobDetail,trigger);
            //启动调度任务
            scheduler.start();
        } catch (SchedulerException e) {
            e.printStackTrace();
        }
    }
}

  执行结果

      

4.总结

        JobExecutionContext可以获取到JobDetail和Trigger的基本属性值，而通过JobDataMap可以获取额外的在jobDetail和triigger初始化时通过方法usingJobData()传递进来的参数。