Exploring Quartz Scheduler http://quartz-scheduler.org Orlando Java User Group Zemian Deng 2011.04.28

Agenda (1.5 hours) Introduction (5 mins) Scheduling Jobs (20 mins) How job is stored and executed (15 mins) Scheduler Deployment (20 mins) Tips for working with quartz API (5 mins) QA session (25 mins)

Introduction: What is Quartz Fancier java.util.Timer Unix CRON replacement A rich API set to the scheduler Job data persistence Job executions control

Creating A Job Class public class SimpleJob implements org.quartz.Job { @Override public void execute(JobExecutionContext ctx) throws JobExecutionException { System.out.println(“job is running”); }

Scheduling One Time Job import org.quartz.JobDetail; import org.quartz.Scheduler; import org.quartz.SimpleTrigger; import org.quartz.impl.StdSchedulerFactory; public class QuartzExample { public static void main(String[] args) throws Exception { Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler(); JobDetail job = new JobDetail("job1", SimpleJob.class); SimpleTrigger trigger = new SimpleTrigger("job1"); scheduler.scheduleJob(job, trigger); scheduler.start(); Thread.sleep(3000L); }

More Scheduling Job Examples One time job with startTime Repeat job now Repeat job with startTime Repeat job forever Cron job

Introduction: Quartz 2.0 vs 1.8 Released in March 2011 New API Java DSL for creating jobs Database schema changes http://quartz-scheduler.org/docs/2.0/newInQuartz2.html

Job Storages In Memory Job Storage - RAMJobStore JDBC Job Storage - JobStoreTX Tx DataSource Job Storage - JobStoreCMT Spring Tx DataSource Job Storage - LocalDataSourceJobStore

Quartz Scheduler Deployment Standalone single JVM/Quartz scheduler Server/Client based via RMI registry Web Container single JVM/Quartz scheduler Allow http client to interact with scheduler! Clustering Quartz scheduler servers

Scheduler Tips #1 SimpleTrigger Total Run Count = RepeatCount - 1 You able to specify an end date regardless of repeatCount. Trigger is NOT sensitive to Daylight Saving Time (DST).

Scheduler Tips #2 CronTrigger Cron Expression has 6 + 1 optional fields. Finest field unit is in second. Trigger is senstive to DST. Day-Of-Week starts with 1=SUN You are allow only one Nth day-of-week (‘#’).

Scheduler Tips #3 Tired of java.util.Calendar & java.util.Date? Use org.quartz.TriggerUtils or Apache commons-langs DateUtils

Scheduler Tips #4 Spring Quartz Scheduler You can’t disable auto shutdown! The dataSource can partake Spring Tx Manager Abstraction. Job may have access to Spring App Context through the Scheduler’s Context space.

Scheduler Tips #5 When using RMI server mode, there is a bug that can crash your scheduler: http://jira.terracotta.org/jira/browse/QTZ-135

Questions?