Java regular tasks Quartz (a) - acquaintance

1 EDITORIAL

Recently the company's business need to use regular tasks, frame selection using a Quartz, here as a learning record.

2 Quartz key members

Quartz core by three large Interface components, namely the Job , the Trigger , Scheduler

2.1 Job

Perform particular tasks described, and its structure is similar to the Runnable, only a method of the type void  Execute (the JobExecutionContext context) , it is also a subclass   InterruptableJob , represents a task may terminate

2.1.1 InterruptableJob 

Based on the Job only added a void type of method  interrupt () , for the termination of the task, it calls occur in QuartzScheduler # shutdown (boolean), which requires that we need to write like a termination of the write execute the same Runnable method.

2.2 Trigger

When used to describe the execute method of performing a Job

2.3 Scheduler

Similar queues and thread pools, storage of various information Job and Trigger, administrative tasks to add, remove, replace, operation, etc.

Preliminary use of 3 Quartz

Scheduler: As a management task container, Scheduler task and should have submitted a similar method to close the pool thread pool: add tasks corresponding method are   the AddJob ,  the scheduleJob , very unfortunately signatures of these methods is  JobDetail ;

JobDetail: JobDetail implementation class has a JobDetailImpl, and represents the empty constructor must specify the name , class , Group . It refers to a class Job  implementation of the interface; Group is optional, use the default default;

Trigger: Trigger a plurality implementation classes, here only involves basically SimpleTriggerImpl;

Corresponding to the above-described construction has three interfaces or class factory class.

3.1 a common timing task

 1 /**
 2  * @author pancc
 3  * @version 1.0
 4  */
 5 public class SimpleJobDemo {
 6     public static void main(String[] args) throws SchedulerException, InterruptedException {
 7         JobDetail detail = JobBuilder.newJob(SimpleJob.class)
 8                 .withIdentity("simple", "group0")
 9                 .build();
10 
11         Trigger trigger = TriggerBuilder.newTrigger()
12                 .withIdentity("simple_trigger")
13                 .startNow()
14                 .withSchedule(SimpleScheduleBuilder.repeatSecondlyForever(2))
15                 .build();
16 
17         Scheduler scheduler = new StdSchedulerFactory().getScheduler();
18 
19         scheduler.start();
20         scheduler.scheduleJob(detail, trigger);
21         /*
22          * 10 秒钟后关闭
23          */
24         Thread.sleep(10_000);
25         scheduler.shutdown();
26     }
27 
28     public static class SimpleJob implements Job {
29         @Override
30         public void execute(JobExecutionContext context) {
31             System.out.printf("now date: %s", new Date());
32         }
33     }
34 
35 }

 

Top of the code creates a task Print task and specify its start time running time of submission, and the period of 2 seconds, last forever. 10 seconds after closing the container.

4 Create a task in the pit

The necessary attributes: JobDetail must have a descriptive name, use the default group when not set.

Accessibility: In a general code, visit our habitual restricted, such as the top of SimpleJob we might define private (meaning its constructor is private ), which is not allowed in Quartz. Job's empty constructor must be pubilc , which is related to the follow-up characteristics of Quartz.