码农code之路我都是分析的jobStore 方式为jdbc的SimpleTrigger！RAM的方式类似分析方式！
说明：
- {0} ：表的前缀 ，如表qrtz_trigger ,{0}== qrtz_
- {1}：quartz.properties 中配置的 org.quartz.scheduler.instanceName: myInstanceName ，{1} ==myInstanceName
如果要使用定时器，那么正常企业级开发中一定是要将任务持久到数据库，那么我们一定明白JobDetail和Trigger是如何操作进入数据库，如何注册到Scheduler中！
一、从一个小Demo开始
那么下面就开始分析源码，分析源码前首先加一个小的demo，方面解释！
//1.创建Scheduler的工厂
SchedulerFactory sf = new StdSchedulerFactory();
//2.从工厂中获取调度器实例
Scheduler scheduler = sf.getScheduler();
//3.创建JobDetail
JobDetail jb = JobBuilder.newJob(RAMJob.class)
.withDescription("this is a ram job") //job的描述
.withIdentity("ramJob", "ramGroup") //job 的name和group
.build();
//任务运行的时间，SimpleSchedle类型触发器有效
long time= System.currentTimeMillis() + 3*1000L; //3秒后启动任务
Date statTime = new Date(time);
//4.创建Trigger
//使用SimpleScheduleBuilder或者CronScheduleBuilder
Trigger t = TriggerBuilder.newTrigger()
.withDescription("")
.withIdentity("ramTrigger", "ramTriggerGroup")
//.withSchedule(SimpleScheduleBuilder.simpleSchedule())
.startAt(statTime) //默认当前时间启动
.withSchedule(CronScheduleBuilder.cronSchedule("0/2 * * * * ?")) //两秒执行一次
.build();
//5.注册任务和定时器
scheduler.scheduleJob(jb, t);//源码分析
//6.启动 调度器
scheduler.start();二、开始源码分析
主要分析入口 scheduleJob ，从这里进去，看看源码里面到底是怎么进行处理的！
//5.注册任务和定时器
scheduler.scheduleJob(jb, t);//源码分析2.1、scheduler.scheduleJob(jb, t);
开始一个任务调度 。scheduler.scheduleJob(jb, t);//源码分析
/**
* <p>
* Calls the equivalent method on the 'proxied' <code>QuartzScheduler</code>.
* 调用“代理”<QuartzScheduler>上的等效方法。
*
* 实现 在 StdScheduler.scheduleJob(JobDetail jobDetail, Trigger trigger)
* </p>
*/
public Date scheduleJob(JobDetail jobDetail, Trigger trigger)
throws SchedulerException {
//这里的sched 是 QuartzScheduler 对象，Quartz和核心类，Quartz调度器
return sched.scheduleJob(jobDetail, trigger);//保存JobDetail和Trigger
}2.2、ched.scheduleJob(jobDetail, trigger);
保存JobDetail和Trigger。ched.scheduleJob(jobDetail, trigger);//保存JobDetail和Trigger
/**
* <p>
* Add the <code>{@link org.quartz.Job}</code> identified by the given
* <code>{@link org.quartz.JobDetail}</code> to the Scheduler, and
* associate the given <code>{@link org.quartz.Trigger}</code> with it.
* </p>
*
* <p>
* If the given Trigger does not reference any <code>Job</code>, then it
* will be set to reference the Job passed with it into this method.
* </p>
*
* @throws SchedulerException
* if the Job or Trigger cannot be added to the Scheduler, or
* there is an internal Scheduler error.
* 将给定org.quartz.JobDetail标识的org.quartz.Job添加到Scheduler，
* 并将给定的org.quartz.Trigger与其关联。
* 如果给定的触发器不引用任何作业，则它将被设置为引用与其一起传递的作业到此方法中。
*
* 实现在 QuartzScheduler.scheduleJob(JobDetail jobDetail,
* Trigger trigger)
*/
public Date scheduleJob(JobDetail jobDetail,
Trigger trigger) throws SchedulerException {
validateState();//验证调度器是否关闭，关闭抛出异常
//检查 jobDetail和trigger
if (jobDetail == null) {
throw new SchedulerException("JobDetail cannot be null");
}
if (trigger == null) {
throw new SchedulerException("Trigger cannot be null");
}
if (jobDetail.getKey() == null) {
throw new SchedulerException("Job's key cannot be null");
}
if (jobDetail.getJobClass() == null) {
throw new SchedulerException("Job's class cannot be null");
}
OperableTrigger trig = (OperableTrigger)trigger;
//getJobKey 获取 getJobName(), getJobGroup()
if (trigger.getJobKey() == null) {
trig.setJobKey(jobDetail.getKey());
} else if (!trigger.getJobKey().equals(jobDetail.getKey())) {
throw new SchedulerException(
"Trigger does not reference given job!");
}
//验证trigger
trig.validate();
Calendar cal = null;
if (trigger.getCalendarName() != null) {
cal = resources.getJobStore().retrieveCalendar(trigger.getCalendarName());//检索Calendar
"SELECT * FROM {0}CALENDARS WHERE SCHED_NAME = {1} AND CALENDAR_NAME = ?"
}
//在触发器首次添加到调度程序时由调度程序调用，以便让触发器基于任何关联的日历计算
//其第一次触发时间。调用此方法后，getNextFireTime（）应返回有效的答案。
Date ft = trig.computeFirstFireTime(cal);
if (ft == null) {
throw new SchedulerException(
"Based on configured schedule, the given trigger '" + trigger.getKey() + "' will never fire.");
}
//存储给定的org.quartz.JobDetail和org.quartz.Trigger。
resources.getJobStore().storeJobAndTrigger(jobDetail, trig);// 主要看这一行
notifySchedulerListenersJobAdded(jobDetail);
notifySchedulerThread(trigger.getNextFireTime().getTime());
notifySchedulerListenersSchduled(trigger);
return ft;
}2.3、 resources.getJobStore().storeJobAndTrigger(jobDetail, trig);
存储给定的org.quartz.JobDetail和org.quartz.Trigger。 resources.getJobStore().storeJobAndTrigger(jobDetail, trig);
public void storeJobAndTrigger(final JobDetail newJob,
final OperableTrigger newTrigger)
throws JobPersistenceException {
executeInLock(
(isLockOnInsert()) ? LOCK_TRIGGER_ACCESS : null,
new VoidTransactionCallback() {
public void executeVoid(Connection conn) throws JobPersistenceException {
//（1）保存JobDetail
storeJob(conn, newJob, false);
//（2）保存Trigger
storeTrigger(conn, newTrigger, newJob, false,
Constants.STATE_WAITING, false, false);
}
});
}2.3.1 storeJob(conn, newJob, false);
保存JobDetail 。storeJob(conn, newJob, false);
首先判断JobDetail是否已经存在，存在则更新，否则插入！
protected void storeJob(Connection conn,
JobDetail newJob, boolean replaceExisting)
throws JobPersistenceException {
//判断JobDetail是否已经存在，根据name和group
boolean existingJob = jobExists(conn, newJob.getKey());
try {
if (existingJob) {
if (!replaceExisting) {
throw new ObjectAlreadyExistsException(newJob);
}
//更新JobDetail
getDelegate().updateJobDetail(conn, newJob);
"UPDATE {0}JOB_DETAILS SET DESCRIPTION = ?, JOB_CLASS_NAME = ?, IS_DURABLE = ?, IS_NONCONCURRENT = ?, IS_UPDATE_DATA = ?, REQUESTS_RECOVERY = ?, JOB_DATA = ? WHERE SCHED_NAME = {1} AND JOB_NAME = ? AND JOB_GROUP = ?"
} else {
//插入JobDetail
getDelegate().insertJobDetail(conn, newJob);
"INSERT INTO {0}JOB_DETAILS (SCHED_NAME, JOB_NAME, JOB_GROUP, DESCRIPTION, JOB_CLASS_NAME, IS_DURABLE, IS_NONCONCURRENT, IS_UPDATE_DATA, REQUESTS_RECOVERY, JOB_DATA) VALUES({1}, ?, ?, ?, ?, ?, ?, ?, ?, ?)"
}
} catch (IOException e) {
throw new JobPersistenceException("Couldn't store job: "
+ e.getMessage(), e);
} catch (SQLException e) {
throw new JobPersistenceException("Couldn't store job: "
+ e.getMessage(), e);
}
}2.３.２ storeTrigger(conn, newTrigger, newJob, false,Constants.STATE_WAITING, false, false);
保存Trigger。 storeTrigger(conn, newTrigger, newJob, false,Constants.STATE_WAITING, false, false);
protected void storeTrigger(Connection conn,
OperableTrigger newTrigger, JobDetail job, boolean replaceExisting, String state,
boolean forceState, boolean recovering)
throws JobPersistenceException {
//判断Trigger是否已经存在，根据name和group
boolean existingTrigger = triggerExists(conn, newTrigger.getKey());
if ((existingTrigger) && (!replaceExisting)) {
throw new ObjectAlreadyExistsException(newTrigger);
}
try {
boolean shouldBepaused;
//进行一些状态的判断
if (!forceState) {
shouldBepaused = getDelegate().isTriggerGroupPaused(
conn, newTrigger.getKey().getGroup());
if(!shouldBepaused) {
shouldBepaused = getDelegate().isTriggerGroupPaused(conn,
ALL_GROUPS_PAUSED);
if (shouldBepaused) {
getDelegate().insertPausedTriggerGroup(conn, newTrigger.getKey().getGroup());
}
}
if (shouldBepaused && (state.equals(STATE_WAITING) || state.equals(STATE_ACQUIRED))) {
state = STATE_PAUSED;
}
}
//若job为null，重新获取！
if(job == null) {
job = getDelegate().selectJobDetail(conn, newTrigger.getJobKey(), getClassLoadHelper());
"SELECT * FROM {0}JOB_DETAILS WHERE SCHED_NAME = {1} AND JOB_NAME = ? AND JOB_GROUP = ?"
}
if (job == null) {
throw new JobPersistenceException("The job ("
+ newTrigger.getJobKey()
+ ") referenced by the trigger does not exist.");
}
//判断是否有DisallowConcurrentExecution注解，recovering恢复
if (job.isConcurrentExectionDisallowed() && !recovering) {
state = checkBlockedState(conn, job.getKey(), state);
"if (jobName != null) {
ps = conn.prepareStatement(rtp(SELECT_FIRED_TRIGGERS_OF_JOB));
"SELECT * FROM {0}FIRED_TRIGGERS WHERE SCHED_NAME = {1} AND JOB_NAME = ? AND JOB_GROUP = ?"
ps.setString(1, jobName);
ps.setString(2, groupName);
} else {
ps = conn
.prepareStatement(rtp(SELECT_FIRED_TRIGGERS_OF_JOB_GROUP));
"SELECT * FROM {0}FIRED_TRIGGERS WHERE SCHED_NAME = {1} AND JOB_GROUP = ?"
ps.setString(1, groupName);
}"
}
if (existingTrigger) {
//更新trigger
getDelegate().updateTrigger(conn, newTrigger, state, job);
" 大概贴出一些，具体想看完整的进入源码看
if(updateJobData) {
ps = conn.prepareStatement(rtp(UPDATE_TRIGGER));
"UPDATE {0}TRIGGERS SET JOB_NAME = ?, JOB_GROUP = ?, DESCRIPTION = ?, NEXT_FIRE_TIME = ?, PREV_FIRE_TIME = ?, TRIGGER_STATE = ?, TRIGGER_TYPE = ?, START_TIME = ?, END_TIME = ?, CALENDAR_NAME = ?, MISFIRE_INSTR = ?, PRIORITY = ?, JOB_DATA = ? WHERE SCHED_NAME = {1} AND TRIGGER_NAME = ? AND TRIGGER_GROUP = ?"
} else {
ps = conn.prepareStatement(rtp(UPDATE_TRIGGER_SKIP_DATA));
"UPDATE {0}TRIGGERS SET JOB_NAME = ?, JOB_GROUP = ?, DESCRIPTION = ?, NEXT_FIRE_TIME = ?, PREV_FIRE_TIME = ?, TRIGGER_STATE = ?, TRIGGER_TYPE = ?, START_TIME = ?, END_TIME = ?, CALENDAR_NAME = ?, MISFIRE_INSTR = ?, PRIORITY = ? WHERE SCHED_NAME = {1} AND TRIGGER_NAME = ? AND TRIGGER_GROUP = ?"
}
"
} else {
//插入trigger
getDelegate().insertTrigger(conn, newTrigger, state, job);
"INSERT INTO {0}TRIGGERS (SCHED_NAME, TRIGGER_NAME, TRIGGER_GROUP, JOB_NAME, JOB_GROUP, DESCRIPTION, NEXT_FIRE_TIME, PREV_FIRE_TIME, TRIGGER_STATE, TRIGGER_TYPE, START_TIME, END_TIME, CALENDAR_NAME, MISFIRE_INSTR, JOB_DATA, PRIORITY) VALUES({1}, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)"
}
} catch (Exception e) {
throw new JobPersistenceException("Couldn't store trigger '" + newTrigger.getKey() + "' for '"
+ newTrigger.getJobKey() + "' job:" + e.getMessage(), e);
}
}到这里，保存就结束了！将任务保存成功后，就可以启动了，期待下一篇源码的分析：Scheduler的start()和QuartzSchedulerThread的run()！
作者：阿飞云 | 来源：https://blog.csdn.net/u010648555/column/info/14251
