Quartz入门 (四) 监听器Listener

　　Quartz的监听器用于当任务调度中你所关注事件发生时，能够及时获取这一事件的通知。类似于任务执行过程中的邮件、短信类的提醒。Quartz 的监听器有Job监听器，Trigger监听器， Scheduler监听器，对不同层面进行监控。三者的使用方法类似，在开始介绍三种监听器之前，需要明确两个概念：全局监听器与非全局监听器，二者的区别在于：全局监听器能够接收到所有的Job/Trigger的事件通知，而非全局监听器只能接收到在其上注册的Job或Trigger的事件，不在其上注册的Job或Trigger则不会进行监听。

JobListener

　　任务调度过程中，与任务Job相关的事件包括：job开始要执行的提示; job执行完成的提示灯。

public interface JobListener {
    
　　String getName();

    void jobToBeExecuted(JobExecutionContext var1);

    void jobExecutionVetoed(JobExecutionContext var1);

    void jobWasExecuted(JobExecutionContext var1, JobExecutionException var2);
}

demo:

自己写一个监听器实现JobListener接口：

public class MailJobListener implements JobListener {

    @Override
    public String getName() {
        return "listener of mail job";
    }

    @Override
    public void jobExecutionVetoed(JobExecutionContext context) {
        System.out.println("取消执行：	 "+context.getJobDetail().getKey());
    }

    @Override
    public void jobToBeExecuted(JobExecutionContext context) {
        System.out.println("准备执行：	 "+context.getJobDetail().getKey());
    }

    @Override
    public void jobWasExecuted(JobExecutionContext context, JobExecutionException arg1) {
        System.out.println("执行结束：	 "+context.getJobDetail().getKey());
        System.out.println();
    }

}

Job:

public class MailJob implements Job {

    @Override
    public void execute(JobExecutionContext jobExecutionContext) throws JobExecutionException {
        JobDetail detail=jobExecutionContext.getJobDetail();
        String email = detail.getJobDataMap().getString("email");

        SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
        String now = sdf.format(new Date());

        System.out.printf("给邮件地址 %s 发出了一封定时邮件, 当前时间是: %s%n" ,email, now);
    }
}

测试：

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

        Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();

        Trigger trigger= newTrigger()
                .withIdentity("trigger1","group1")
                .startNow()
                .withSchedule(simpleSchedule().withIntervalInSeconds(1).withRepeatCount(5))
                .build();

        JobDetail jobDetail=newJob(MailJob.class)
                .withIdentity("job1","group1")
                .usingJobData("email","臭弟弟")
                .build();

//这是自己写的那个监听器：
        MailJobListener mailJobListener=new MailJobListener();
//构造匹配pickNewsJob中的JobKey的keyMatcher
        KeyMatcher<JobKey> keyMatcher = KeyMatcher.keyEquals(jobDetail.getKey());
//加入调度器：
        scheduler.getListenerManager().addJobListener(mailJobListener,keyMatcher);

        scheduler.scheduleJob(jobDetail,trigger);
        scheduler.start();

        Thread.sleep(20000);
        scheduler.shutdown();
    }
}