Quartz的Hello world

1.准备环境jar包

Your project will need (at least) the Quartz core library, named quartz-x.y.z.jar (where x.y.z is a version number), in its classpath.if you are a Maven user you can add the dependencies (only the first below is required):

 <dependency>
      <groupId>org.quartz-scheduler</groupId>
      <artifactId>quartz</artifactId>
      <version>2.2.1</version>
  </dependency>
  <dependency>
      <groupId>org.quartz-scheduler</groupId>
      <artifactId>quartz-jobs</artifactId>
      <version>2.2.1</version>
  </dependency>
2.通过工厂调用Schedulers，只有当start()方法被调用时，才会触发定时器操作。

// Grab the Scheduler instance from the Factory
  Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();

  // and start it off
  scheduler.start();

3.引入相关API

　import org.quartz.Scheduler;
  import org.quartz.SchedulerException;
  import org.quartz.impl.StdSchedulerFactory;
  import static org.quartz.JobBuilder.*;
  import static org.quartz.TriggerBuilder.*;

 import static org.quartz.SimpleScheduleBuilder.*;

4.实现Job接口，并编写execute方法

public class MyJob implements org.quartz.Job {

      public MyJob() {
      }

      public void execute(JobExecutionContext context) throws JobExecutionException {
          System.err.println("Hello World!  MyJob is executing.");
      }
  }
5.And then schedule those jobs with triggers that define at what time(s) the job should run.

// define the job and tie it to our MyJob class
  JobDetail job = newJob(MyJob.class)
      .withIdentity("job1", "group1")
      .build();

  // Trigger the job to run now, and then repeat every 40 seconds
  Trigger trigger = newTrigger()
      .withIdentity("trigger1", "group1")
      .startNow()
      .withSchedule(simpleSchedule()
              .withIntervalInSeconds(40)
              .repeatForever())
      .build();

  // Tell quartz to schedule the job using our trigger
  scheduler.scheduleJob(job, trigger);