阿里的面试官问,如果现在很多调度任务,如何优化,可以使用调度池参考:ScheduledExecutor,
参考:Java 几种调度任务的Timer、ScheduledExecutor、 开源工具包 Quartz、开源工具包 JCronTab
言归正传:
Quartz是一个开放源码项目,专注于任务调度器,提供了极为广泛的特性如持久化任务,集群和分布式任务等。 Quartz核心是调度器,还采用多线程管理。
1.持久化任务:当应用程序停止运行时,所有调度信息不被丢失,当你重新启动时,调度信息还存在,这就是持久化任务。
2.集群和分布式处理:当在集群环境下,当有配置Quartz的多个客户端时(节点),采用Quartz的集群和分布式处理时,我们要了解几点好处
1) 一个节点无法完成的任务,会被集群中拥有相同的任务的节点取代执行。
2) Quartz调度是通过触发器的类别来识别不同的任务,在不同的节点定义相同的触发器的类别,这样在集群下能稳定的运行,一个节点无法完成的任务,会被集群中拥有相同的任务的节点取代执行。
3)分布式 体现在 当相同的任务定时在一个时间点,在那个时间点,不会被两个节点同时执行。
Quartz的 Task(11 张表)实例化采用数据库存储,基于数据库引擎及 High-Available 的策略(集群的一种策略)自动协调每个节点的 Quartz。
delete from qrtz_fired_triggers; delete from qrtz_simple_triggers; delete from qrtz_simprop_triggers; delete from qrtz_cron_triggers; delete from qrtz_blob_triggers; delete from qrtz_triggers; delete from qrtz_job_details; delete from qrtz_calendars; delete from qrtz_paused_trigger_grps; delete from qrtz_locks; delete from qrtz_scheduler_state; CREATE TABLE qrtz_job_details ( SCHED_NAME VARCHAR2(120) NOT NULL, JOB_NAME VARCHAR2(200) NOT NULL, JOB_GROUP VARCHAR2(200) NOT NULL, DESCRIPTION VARCHAR2(250) NULL, JOB_CLASS_NAME VARCHAR2(250) NOT NULL, IS_DURABLE VARCHAR2(1) NOT NULL, IS_NONCONCURRENT VARCHAR2(1) NOT NULL, IS_UPDATE_DATA VARCHAR2(1) NOT NULL, REQUESTS_RECOVERY VARCHAR2(1) NOT NULL, JOB_DATA BLOB NULL, CONSTRAINT QRTZ_JOB_DETAILS_PK PRIMARY KEY (SCHED_NAME,JOB_NAME,JOB_GROUP) ); CREATE TABLE qrtz_triggers ( SCHED_NAME VARCHAR2(120) NOT NULL, TRIGGER_NAME VARCHAR2(200) NOT NULL, TRIGGER_GROUP VARCHAR2(200) NOT NULL, JOB_NAME VARCHAR2(200) NOT NULL, JOB_GROUP VARCHAR2(200) NOT NULL, DESCRIPTION VARCHAR2(250) NULL, NEXT_FIRE_TIME NUMBER(13) NULL, PREV_FIRE_TIME NUMBER(13) NULL, PRIORITY NUMBER(13) NULL, TRIGGER_STATE VARCHAR2(16) NOT NULL, TRIGGER_TYPE VARCHAR2(8) NOT NULL, START_TIME NUMBER(13) NOT NULL, END_TIME NUMBER(13) NULL, CALENDAR_NAME VARCHAR2(200) NULL, MISFIRE_INSTR NUMBER(2) NULL, JOB_DATA BLOB NULL, CONSTRAINT QRTZ_TRIGGERS_PK PRIMARY KEY (SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP), CONSTRAINT QRTZ_TRIGGER_TO_JOBS_FK FOREIGN KEY (SCHED_NAME,JOB_NAME,JOB_GROUP) REFERENCES QRTZ_JOB_DETAILS(SCHED_NAME,JOB_NAME,JOB_GROUP) ); CREATE TABLE qrtz_simple_triggers ( SCHED_NAME VARCHAR2(120) NOT NULL, TRIGGER_NAME VARCHAR2(200) NOT NULL, TRIGGER_GROUP VARCHAR2(200) NOT NULL, REPEAT_COUNT NUMBER(7) NOT NULL, REPEAT_INTERVAL NUMBER(12) NOT NULL, TIMES_TRIGGERED NUMBER(10) NOT NULL, CONSTRAINT QRTZ_SIMPLE_TRIG_PK PRIMARY KEY (SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP), CONSTRAINT QRTZ_SIMPLE_TRIG_TO_TRIG_FK FOREIGN KEY (SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP) REFERENCES QRTZ_TRIGGERS(SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP) ); CREATE TABLE qrtz_cron_triggers ( SCHED_NAME VARCHAR2(120) NOT NULL, TRIGGER_NAME VARCHAR2(200) NOT NULL, TRIGGER_GROUP VARCHAR2(200) NOT NULL, CRON_EXPRESSION VARCHAR2(120) NOT NULL, TIME_ZONE_ID VARCHAR2(80), CONSTRAINT QRTZ_CRON_TRIG_PK PRIMARY KEY (SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP), CONSTRAINT QRTZ_CRON_TRIG_TO_TRIG_FK FOREIGN KEY (SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP) REFERENCES QRTZ_TRIGGERS(SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP) ); CREATE TABLE qrtz_simprop_triggers ( SCHED_NAME VARCHAR2(120) NOT NULL, TRIGGER_NAME VARCHAR2(200) NOT NULL, TRIGGER_GROUP VARCHAR2(200) NOT NULL, STR_PROP_1 VARCHAR2(512) NULL, STR_PROP_2 VARCHAR2(512) NULL, STR_PROP_3 VARCHAR2(512) NULL, INT_PROP_1 NUMBER(10) NULL, INT_PROP_2 NUMBER(10) NULL, LONG_PROP_1 NUMBER(13) NULL, LONG_PROP_2 NUMBER(13) NULL, DEC_PROP_1 NUMERIC(13,4) NULL, DEC_PROP_2 NUMERIC(13,4) NULL, BOOL_PROP_1 VARCHAR2(1) NULL, BOOL_PROP_2 VARCHAR2(1) NULL, CONSTRAINT QRTZ_SIMPROP_TRIG_PK PRIMARY KEY (SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP), CONSTRAINT QRTZ_SIMPROP_TRIG_TO_TRIG_FK FOREIGN KEY (SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP) REFERENCES QRTZ_TRIGGERS(SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP) ); CREATE TABLE qrtz_blob_triggers ( SCHED_NAME VARCHAR2(120) NOT NULL, TRIGGER_NAME VARCHAR2(200) NOT NULL, TRIGGER_GROUP VARCHAR2(200) NOT NULL, BLOB_DATA BLOB NULL, CONSTRAINT QRTZ_BLOB_TRIG_PK PRIMARY KEY (SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP), CONSTRAINT QRTZ_BLOB_TRIG_TO_TRIG_FK FOREIGN KEY (SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP) REFERENCES QRTZ_TRIGGERS(SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP) ); CREATE TABLE qrtz_calendars ( SCHED_NAME VARCHAR2(120) NOT NULL, CALENDAR_NAME VARCHAR2(200) NOT NULL, CALENDAR BLOB NOT NULL, CONSTRAINT QRTZ_CALENDARS_PK PRIMARY KEY (SCHED_NAME,CALENDAR_NAME) ); CREATE TABLE qrtz_paused_trigger_grps ( SCHED_NAME VARCHAR2(120) NOT NULL, TRIGGER_GROUP VARCHAR2(200) NOT NULL, CONSTRAINT QRTZ_PAUSED_TRIG_GRPS_PK PRIMARY KEY (SCHED_NAME,TRIGGER_GROUP) ); CREATE TABLE qrtz_fired_triggers ( SCHED_NAME VARCHAR2(120) NOT NULL, ENTRY_ID VARCHAR2(95) NOT NULL, TRIGGER_NAME VARCHAR2(200) NOT NULL, TRIGGER_GROUP VARCHAR2(200) NOT NULL, INSTANCE_NAME VARCHAR2(200) NOT NULL, FIRED_TIME NUMBER(13) NOT NULL, SCHED_TIME NUMBER(13) NOT NULL, PRIORITY NUMBER(13) NOT NULL, STATE VARCHAR2(16) NOT NULL, JOB_NAME VARCHAR2(200) NULL, JOB_GROUP VARCHAR2(200) NULL, IS_NONCONCURRENT VARCHAR2(1) NULL, REQUESTS_RECOVERY VARCHAR2(1) NULL, CONSTRAINT QRTZ_FIRED_TRIGGER_PK PRIMARY KEY (SCHED_NAME,ENTRY_ID) ); CREATE TABLE qrtz_scheduler_state ( SCHED_NAME VARCHAR2(120) NOT NULL, INSTANCE_NAME VARCHAR2(200) NOT NULL, LAST_CHECKIN_TIME NUMBER(13) NOT NULL, CHECKIN_INTERVAL NUMBER(13) NOT NULL, CONSTRAINT QRTZ_SCHEDULER_STATE_PK PRIMARY KEY (SCHED_NAME,INSTANCE_NAME) ); CREATE TABLE qrtz_locks ( SCHED_NAME VARCHAR2(120) NOT NULL, LOCK_NAME VARCHAR2(40) NOT NULL, CONSTRAINT QRTZ_LOCKS_PK PRIMARY KEY (SCHED_NAME,LOCK_NAME) ); create index idx_qrtz_j_req_recovery on qrtz_job_details(SCHED_NAME,REQUESTS_RECOVERY); create index idx_qrtz_j_grp on qrtz_job_details(SCHED_NAME,JOB_GROUP); create index idx_qrtz_t_j on qrtz_triggers(SCHED_NAME,JOB_NAME,JOB_GROUP); create index idx_qrtz_t_jg on qrtz_triggers(SCHED_NAME,JOB_GROUP); create index idx_qrtz_t_c on qrtz_triggers(SCHED_NAME,CALENDAR_NAME); create index idx_qrtz_t_g on qrtz_triggers(SCHED_NAME,TRIGGER_GROUP); create index idx_qrtz_t_state on qrtz_triggers(SCHED_NAME,TRIGGER_STATE); create index idx_qrtz_t_n_state on qrtz_triggers(SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP,TRIGGER_STATE); create index idx_qrtz_t_n_g_state on qrtz_triggers(SCHED_NAME,TRIGGER_GROUP,TRIGGER_STATE); create index idx_qrtz_t_next_fire_time on qrtz_triggers(SCHED_NAME,NEXT_FIRE_TIME); create index idx_qrtz_t_nft_st on qrtz_triggers(SCHED_NAME,TRIGGER_STATE,NEXT_FIRE_TIME); create index idx_qrtz_t_nft_misfire on qrtz_triggers(SCHED_NAME,MISFIRE_INSTR,NEXT_FIRE_TIME); create index idx_qrtz_t_nft_st_misfire on qrtz_triggers(SCHED_NAME,MISFIRE_INSTR,NEXT_FIRE_TIME,TRIGGER_STATE); create index idx_qrtz_t_nft_st_misfire_grp on qrtz_triggers(SCHED_NAME,MISFIRE_INSTR,NEXT_FIRE_TIME,TRIGGER_GROUP,TRIGGER_STATE); create index idx_qrtz_ft_trig_inst_name on qrtz_fired_triggers(SCHED_NAME,INSTANCE_NAME); create index idx_qrtz_ft_inst_job_req_rcvry on qrtz_fired_triggers(SCHED_NAME,INSTANCE_NAME,REQUESTS_RECOVERY); create index idx_qrtz_ft_j_g on qrtz_fired_triggers(SCHED_NAME,JOB_NAME,JOB_GROUP); create index idx_qrtz_ft_jg on qrtz_fired_triggers(SCHED_NAME,JOB_GROUP); create index idx_qrtz_ft_t_g on qrtz_fired_triggers(SCHED_NAME,TRIGGER_NAME,TRIGGER_GROUP); create index idx_qrtz_ft_tg on qrtz_fired_triggers(SCHED_NAME,TRIGGER_GROUP);
我在新建一个张表,为了方便页面能对每个任务进行管理,能对具体某个任务设置开始时间、结束时间、执行的方法、删除等, 如下面图所示:
在这边可以管理开始时间和结束时间和cronExpression值,方便管理对应表的设计:
表都设计好了,整理Quartz集成springMVC的具体的实现。
对spring的@component 的说明:@component (把普通pojo实例化到spring容器中,相当于配置文件中的<bean id="" class=""/>)
1.举例两个任务具体实现功能,列如quartzJobA和quartzJobB任务要做什么,新建了两个类和方法。
#Main Scheduler Settings org.quartz.scheduler.instanceName=quartzScheduler org.quartz.scheduler.instanceId=AUTO org.quartz.scheduler.threadsInheritContextClassLoaderOfInitializer=true org.quartz.scheduler.skipUpdateCheck=true org.quartz.scheduler.batchTriggerAcquisitionMaxCount=100 org.quartz.threadPool.threadCount=10 #Configure JDBC-JobStoreTX org.quartz.jobStore.class = org.quartz.impl.jdbcjobstore.JobStoreTX org.quartz.jobStore.driverDelegateClass=org.quartz.impl.jdbcjobstore.oracle.OracleDelegate org.quartz.jobStore.dataSource=myDS org.quartz.jobStore.tablePrefix=QRTZ_ org.quartz.jobStore.isClustered=true org.quartz.jobStore.acquireTriggersWithinLock=true org.quartz.jobStore.clusterCheckinInterval = 30000 #Configure DataSources org.quartz.dataSource.myDS.driver=com.alibaba.druid.proxy.DruidDriver org.quartz.dataSource.myDS.URL=jdbc:wrap-jdbc:filters=default:name=dragoon:jdbc:oracle:thin:@127.0.0.1:1521:test org.quartz.dataSource.myDS.user= org.quartz.dataSource.myDS.password= org.quartz.dataSource.myDS.maxConnections=5 org.quartz.dataSource.myDS.validationQuery=select 1 from dual
org.quartz.scheduler.instanceName 属性可为任何值,用在 JDBC JobStore 中来唯一标识实例,但是所有集群节点中必须相同
org.quartz.jobStore.class属性为 JobStoreTX,将任务持久化到数据中。因为集群中节点依赖于数据库来传播 Scheduler 实例的状态,你只能在使用 JDBC JobStore 时应用 Quartz 集群。这意味着你必须使用 JobStoreTX 或是 JobStoreCMT 作为 Job 存储;你不能在集群中使用 RAMJobStore
3.实现任务的创建和管理
@Component("schedulerHelper") public class SchedulerHelper { private static final String CONFIG_FILE="quartz-job.properties"; private static final String IDENTITY_JOB_PREFIX="job_"; private static final String IDENTITY_TRIGGER_PREFIX="trigger_"; @Autowired private JobService jobService;//jobService 这个服务是实现管理任务的页面的服务实现 private Scheduler scheduler; @Autowired private StartJobSchedulerListener startJobSchedulerListener;//实现自己的Scheduler监听器,程序启动时,任务没创建时就创建 /** * tomcat一启动时,类实例化时就执行 */ public void init() { try{ // 创建一个定时器工厂 StdSchedulerFactory sf = new StdSchedulerFactory(); //初始化quartz-job.properties配置文件 sf.initialize(Thread.currentThread().getContextClassLoader().getResource(CONFIG_FILE).getFile()); scheduler = sf.getScheduler(); //把jobService放到scheduler上下文,job执行是可以获取并访问。 scheduler.getContext().put(SCHEDULER_KEY_JOBSERVICE,jobService); startJobSchedulerListener.setSchedulerHelper(this); //设置自己的监听器 scheduler.getListenerManager().addSchedulerListener(startJobSchedulerListener); // 启动定时器 scheduler.start(); logger.info("====================job scheduler start"); }catch(SchedulerException e){ logger.error("error",e); } } /** * 根据jobentity创建并开始任务 */ public boolean createAndStartJob(JobEntity job) { JobDetail jobDetail=generateJobDetail(job); Trigger trigger=generateTriggerBuilder(job).build(); try { scheduler.scheduleJob(jobDetail, trigger); return true; } catch (SchedulerException e) { logger.error("scheduler.scheduleJob",e); return false; } } /** * 清除 */ public void clearAllScheduler() { try { scheduler.clear(); } catch (SchedulerException e) { logger.error("clearAllScheduler",e); } } /** * 根据jobId和类型删除 */ public boolean removeJob(Long jobId,String jobType) { try { scheduler.deleteJob(getJobKey(jobId,jobType)); return true; } catch (SchedulerException e) { logger.error("removeJob",e); return false; } } /** * 暂停任务 */ public boolean pauseJob(Long jobId,String jobType) { try { scheduler.pauseJob(getJobKey(jobId,jobType)); return true; } catch (SchedulerException e) { logger.error("resumeJob",e); return false; } } /** * 马上只执行一次任务 */ public boolean executeOneceJob(Long jobId,String jobType) { try { Calendar end=Calendar.getInstance(); TriggerBuilder<SimpleTrigger> simpleTriggerBuilder=TriggerBuilder.newTrigger() .withIdentity(getTriggerKey(jobId,jobType)) .forJob(getJobKey(jobId,jobType)) .withSchedule(SimpleScheduleBuilder.simpleSchedule().withIntervalInSeconds(2)); end.add(Calendar.SECOND, 2); simpleTriggerBuilder.startAt(end.getTime()); end.add(Calendar.SECOND, 5); simpleTriggerBuilder.endAt(end.getTime()); JobEntity job=jobService.getJobById(jobId); JobDataMap jobDataMap=new JobDataMap(); jobDataMap.put("jobEntity", job); simpleTriggerBuilder.usingJobData(jobDataMap); Trigger trigger=simpleTriggerBuilder.build(); scheduler.scheduleJob(trigger); return true; } catch (SchedulerException e) { logger.error("executeOneceJob",e); return false; } } /** * 启动一些scheduler里没有的active的jobDetail */ public void createActiveJobFromDB() throws SchedulerException { List<JobEntity> jobs=jobService.getActiveJob(); for(JobEntity job:jobs) { if(scheduler.getJobDetail(getJobKey(job))==null) createAndStartJob(job); } } /** * 获得任务的jobKey */ public static JobKey getJobKey(Long jobId,String jobType) { return new JobKey(IDENTITY_JOB_PREFIX+jobId,IDENTITY_JOB_PREFIX+jobType); } /** * 获得任务的jobKey */ public static JobKey getJobKey(JobEntity job) { return new JobKey(IDENTITY_JOB_PREFIX+job.getJobId(),IDENTITY_JOB_PREFIX+job.getJobType()); } /** * 获得trigger的triggerkey */ public static TriggerKey getTriggerKey(JobEntity job) { return new TriggerKey(IDENTITY_TRIGGER_PREFIX+job.getJobId()+"_"+System.currentTimeMillis(), IDENTITY_TRIGGER_PREFIX+job.getJobType()); } /** * 获得trigger的triggerkey */ public static TriggerKey getTriggerKey(Long jobId,String jobType) { return new TriggerKey(IDENTITY_TRIGGER_PREFIX+jobId+"_"+System.currentTimeMillis(), IDENTITY_TRIGGER_PREFIX+jobType); } public static JobDetail generateJobDetail(JobEntity job) { JobDataMap jobDataMap=new JobDataMap(); jobDataMap.put("jobEntity", job); Class<? extends Job> clazz=null; clazz=BeanJob.class; return JobBuilder.newJob(clazz) .withIdentity(getJobKey(job)) .usingJobData(jobDataMap) .requestRecovery(true).storeDurably(true) .build(); } /** * 根据jobEntity获得trigger */ public static TriggerBuilder<CronTrigger> generateTriggerBuilder(JobEntity job) { TriggerBuilder<CronTrigger> triggerBuilder= TriggerBuilder.newTrigger() .withIdentity(getTriggerKey(job)) .withSchedule(CronScheduleBuilder.cronSchedule(job.getCronExpr()) .withMisfireHandlingInstructionDoNothing()); if(job.getSyncBeginTime()!=null) triggerBuilder.startAt(job.getSyncBeginTime()); else triggerBuilder.startNow(); if(job.getSyncEndTime()!=null) triggerBuilder.endAt(job.getSyncEndTime()); return triggerBuilder; } public static JobService getJobService(JobExecutionContext context) { try { return (JobService) context.getScheduler().getContext().get(SchedulerHelper.SCHEDULER_KEY_JOBSERVICE); } catch (SchedulerException e) { logger.error("SchedulerHelper.getJobService",e); return null; } }
4.实现自己的Scheduler监听器,程序启动时,创建scheduler里没有的active的jobDetail
@Component(value="startJobSchedulerListener") public class StartJobSchedulerListener extends SchedulerListenerSupport { private SchedulerHelper schedulerHelper; @Override public void schedulerStarted() { try { schedulerHelper.createActiveJobFromDB(); } catch (SchedulerException e) { logger.error("createActiveJobFromDB",e); } } public SchedulerHelper getSchedulerHelper() { return schedulerHelper; } public void setSchedulerHelper(SchedulerHelper schedulerHelper) { this.schedulerHelper = schedulerHelper; } }
5.实现的是一个job实例对应一个线程并实现页面配置对应的哪个类和方法
public abstract class AbstractEdiJob implements Job { protected JobEntity jobEntity; protected static final Logger logger=LoggerFactory.getLogger(AbstractEdiJob.class); private Long beginTime; @Override public void execute(JobExecutionContext context) throws JobExecutionException { JobService jobService=SchedulerHelper.getJobService(context); preExcute(jobService,context); exeucuteInternal(context); postExcute(jobService,context); } abstract public void exeucuteInternal(JobExecutionContext context); public void preExcute(JobService jobService,JobExecutionContext context) { beginTime=System.currentTimeMillis(); } public void postExcute(JobService jobService,JobExecutionContext context) { //获得最新的jobEntiry jobEntity=jobService.getJobById(jobEntity.getJobId()); if(jobEntity==null) { logger.warn(jobEntity.getJobId()+"job不能存在"); return; } if(context.getFireTime()!=null) jobEntity.setRuntimeLast(context.getFireTime()); if(context.getNextFireTime()!=null) jobEntity.setRuntimeNext(context.getNextFireTime()); /* else jobEntity.setJobStatus();*/ Long times=jobEntity.getRunTimes(); jobEntity.setRunTimes((times==null?0l:times)+1); Long duration=jobEntity.getRunDuration(); jobEntity.setRunDuration((duration==null?0l:duration)+(System.currentTimeMillis()-beginTime)); jobService.updateJob(jobEntity); //jobEntity这里的改变不能改变JobDetail里的JobEntity,因为生产的job是JobDetail的JobEntity的复制 } public void setJobEntity(JobEntity jobEntity) { this.jobEntity = jobEntity; } }
/** *执行具体类中的方法 **/ public class BeanJob extends AbstractEdiJob { private static Logger logger=LoggerFactory.getLogger(BeanJob.class); @Override public void exeucuteInternal(JobExecutionContext context) { Object obj=SpringContextUtil.getBean(jobEntity.getJobObject()); try { Method method=obj.getClass().getMethod(jobEntity.getJobMethod()); method.invoke(obj); } catch (SecurityException e) { logger.error("error",e); } catch (NoSuchMethodException e) { logger.error("error",e); } catch (IllegalArgumentException e) { logger.error("error",e); } catch (IllegalAccessException e) { logger.error("error",e); } catch (InvocationTargetException e) { logger.error("error",e); } } }
6.新增一个任务时,数据库就保存对应的触发器,变成持久化任务,如图所示:
1.用StdSchedulerFactory来获取Scheduler的实例,scheduler有启动(start)、中止(stop)和暂停(pause)方法。
2.JobDataMap实例,JobDataMap jobDataMap=new JobDataMap();jobDataMap.put("jobEntity", job);在同一任务的多次执行之间传递数据
3.创建JobDetail实例。JobBuilder.newJob(clazz).withIdentity(getJobKey(job)).usingJobData(jobDataMap).requestRecovery(true).storeDurably(true).build();返回JobDetail实例,newJob(clazz)是要执行特定任务的类;withIdentity(getJobKey(job))是job的任务名和组名;usingJobDatausingJobData(jobDataMap)传输数据;
4.创建Trigger实例。TriggerBuilder<CronTrigger> triggerBuilder= TriggerBuilder.newTrigger()
.withIdentity(getTriggerKey(job))
.withSchedule(CronScheduleBuilder.cronSchedule(job.getCronExpr())
.withMisfireHandlingInstructionDoNothing());
withIdentity有标示了触发器的名称和组(Quartz调度是通过触发器的类别来识别不同的任务),和withSchedule标示执行的时间表达式
5.最后通过scheduler.scheduleJob()方法调度任务。