精进Quartz源码—Quartz中JobStore保存JonDetail和Trigger源码分析(一)

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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()!

三、参考资料

quartz2.2源码分析4-JobStore

Quartz专栏系列

1.精进Quartz——Quartz大致介绍(一)
2.精进Quartz——Quartz简单入门Demo(二)
3.精进Quartz——Spring和Quartz集成详解
4.精进Quartz——SSMM(Spring+SpringMVC+Mybatis+Mysql)和Quartz集成详解(四)
5.精进Quartz源码——JobStore保存JonDetail和Trigger源码分析(一)
6.精进Quartz源码——scheduler.start()启动源码分析(二)
7.精进Quartz源码——QuartzSchedulerThread.run() 源码分析(三)
8.精进Quartz源码——Quartz调度器的Misfire处理规则(四)


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