java quartz调度程序在特定时间运行

Question

例如，我想写一个Java程序在每天凌晨12点打印“Hello World”，我该如何使用Quartz调度器来实现呢？

Trigger trigger = TriggerUtils.makeDailyTrigger(0, 0);
trigger.setName("trigger1");
trigger.setGroup("group1");

像这样？我应该在哪里打印“hello world”方法？

Answer 1

您可以使用表达式来安排作业的执行。例如:

public static class HelloJob implements Job {
    @Override
    public void execute(JobExecutionContext ctx) throws JobExecutionException {
        System.out.println("Hello World");
    }
}

public static void main(String[] args) throws SchedulerException {
    String exp = "0 0 0 1/1 * ? *";

    SchedulerFactory factory = new StdSchedulerFactory();
    Scheduler scheduler = factory.getScheduler();
    scheduler.start();
    JobDetail job = JobBuilder.newJob(HelloJob.class).build();
    Trigger trigger = TriggerBuilder.newTrigger()
                                    .startNow()
                                    .withSchedule(
                                         CronScheduleBuilder.cronSchedule(exp))
                                    .build();
    scheduler.scheduleJob(job, trigger);
}

参见 http://www.cronmaker.com/用于构建另一个表达式。例如0 0/1 * 1/1 * ？ * 每分钟查看输出。另见 Cron Expressions .