Quartz学习--二 Hello Quartz! 和源码分析

Quartz学习--二  Hello Quartz! 和源码分析

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三.  Hello Quartz!

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我会跟着 第一章 6.2 的图来 进行同步代码编写

1. 简单入门示例:

   1. 创建一个新的java普通工程 引入对应版本jar包:

      jar包 maven地址为:

         <!-- Quartz jar 包 2.2.1 版本 -->
              <dependency>
                  <groupId>org.quartz-scheduler</groupId>
                  <artifactId>quartz</artifactId>
                  <version>2.2.1</version>
              </dependency>
              <dependency>
                  <groupId>org.quartz-scheduler</groupId>
                  <artifactId>quartz-jobs</artifactId>
                  <version>2.2.1</version>
              </dependency>
              <!-- 若你使用的框架是SpringBoot 需要引入:
                  这里只是个示例简单程序  所以只需要导入上面两个的依赖就可
              -->
              <!--<dependency>-->
                  <!--<groupId>org.springframework</groupId>-->
                  <!--<artifactId>spring-context-support</artifactId>-->
                  <!--<version>4.1.6.RELEASE</version>-->
              <!--</dependency>-->

   2. 自创建任务 (Job)

      仅仅需要对 org.quartz.Job 接口进行实现 将来调度器会执行我们重写的execute()方法

      package com.ws.quartzdemo1001.job01_HelloWorld;
      ​
      import org.quartz.Job;
      import org.quartz.JobExecutionContext;
      import org.quartz.JobExecutionException;
      import org.slf4j.Logger;
      import org.slf4j.LoggerFactory;
      ​
      /**
       * 实现 quartz 对使用人员开放的 Job接口
       */
      public class HelloJob implements Job {
      ​
          private static Logger log = LoggerFactory.getLogger(HelloJob.class);
      ​
          @Override
          public void execute(JobExecutionContext jobExecutionContext)
                  throws JobExecutionException {
              log.info("Hello Quartz - Job");
          }
      }

   3. 编写使用Quartz的代码

      ​

      package com.ws.quartzdemo1001.job01_HelloWorld;
      ​
      import org.quartz.*;
      import org.quartz.impl.StdSchedulerFactory;
      import org.slf4j.Logger;
      import org.slf4j.LoggerFactory;
      import java.util.Date;
      ​
      public class HelloQuartz {
          private static Logger logger = LoggerFactory.getLogger(HelloQuartz.class);
      ​
          public static void main(String[] args) throws SchedulerException {
              // 1 创建 Scheduler 的工厂
              SchedulerFactory schedulerFactory = new StdSchedulerFactory();
              // 2 从工厂中获取调度器 的实例
              Scheduler scheduler = schedulerFactory.getScheduler();
              // 3 创建JobDetail
              JobDetail jobDetail = JobBuilder.newJob(HelloJob.class)
                      .withDescription("this is my first job01_HelloWorld ")  // 设置job相关描述
                      .withIdentity("hello job01_HelloWorld" ,"normal job01_HelloWorld") // 设置任务 名称和组名
                      .build(); //创建 JobDetail
              // 4 创建 trigger
              CronTrigger trigger = TriggerBuilder.newTrigger()
                      .withDescription("this is my first trigger") //设置 trigger 相关描述
                      .withIdentity("say hello trigger", "cron trigger") //设置 当前触发其 名字 和归属组名
                      .startAt(new Date()) // 设置任务启动时间
                      .withSchedule(CronScheduleBuilder.cronSchedule("0/10 * * * * ?"))
                      .build();
              // 5 将 job01_HelloWorld 和 trigger 绑定 并注册到 调度器
              scheduler.scheduleJob(jobDetail,trigger);
              // 6 启动 调度器
              scheduler.start();
              logger.info(new Date() +"    <<<<<<  启动");
          }
      }

      主要编写了:

      • 创建了Scheduler 工厂

      • 从工厂中获取调度器的实例

      • 使用自己实现了Job接口的类 来创建 JobDetail

      • 创建触发器 并指定触发规则

      • 将JobDetail 和触发器进行绑定放入 调度器中 (或者说注册到scheduler)

      • 启动调度器

   4. 执行结果:

   5. 

1. 入门示例 (追根溯源)

• 作为一个简单的应用程序 我们使用起来给我最大的感触就是 每个主要实例都有一个特定的创建方法

  比如 调度器实例就是依靠 Scheduler工厂而创建出来为我们使用

  JobDetail 和Trigger 亦是如此

• HelloJob代码分析:

  接口: org.quartz.Job

  // Source code recreated from a .class file by IntelliJ IDEA
  // (powered by Fernflower decompiler)
  ​
  package org.quartz;
  ​
  public interface Job {
      void execute(JobExecutionContext context) throws JobExecutionException;
  }

  ​

  一个任务是一个实现Job接口的类, 且任务类必须含有空构造器

  当关联这个任务实例的触发器声明的执行时间到了的时候,调度程序Scheduler 会调用这个execute()方法来执行任务,我们的任务内容就可以在这个方法中执行

  JobExecutionContext: 工作执行的上下文 自动传入

  ​ 实际上在该方法退出之前会设置一个结果对象到 上下文中 ,

  ​ 来让JobListeners 或者TriggerListeners 获得当前任务执行的状态

  • HelloQuartz 代码分析:

     // 1 创建 Scheduler 的工厂
            SchedulerFactory schedulerFactory = new StdSchedulerFactory();

    创建一个生产调度器的工厂

    查看Scheduler 接口源码:

    // Source code recreated from a .class file by IntelliJ IDEA
    // (powered by Fernflower decompiler)
    ​
    package org.quartz;
    ​
    import java.util.Collection;
    ​
    public interface SchedulerFactory {
        Scheduler getScheduler() throws SchedulerException;
    ​
        Scheduler getScheduler(String var1) throws SchedulerException;
    ​
        Collection<Scheduler> getAllSchedulers() throws SchedulerException;
    }
    ​

    接口规范了 三个必须实现的方法:

    ​ 三个方法的作用实际上都是 来获取 调度器实例

    • getScheduler()

    • getScheduler(String schedName) // 返回指定了名字的调度器实例

    • getAllSchedulers()

    Scheduler 的实现有 两种:

    ​

    代码中创建的是 new StdSchedulerFactory() ;

    查看 DirectSchedulerFactory 中实现代码:

    public class DirectSchedulerFactory implements SchedulerFactory {
        public static final String DEFAULT_INSTANCE_ID = "SIMPLE_NON_CLUSTERED";
        public static final String DEFAULT_SCHEDULER_NAME = "SimpleQuartzScheduler";
        private static final boolean DEFAULT_JMX_EXPORT = false;
        private static final String DEFAULT_JMX_OBJECTNAME = null;
        private static final DefaultThreadExecutor DEFAULT_THREAD_EXECUTOR = new DefaultThreadExecutor();
        private static final int DEFAULT_BATCH_MAX_SIZE = 1;
        private static final long DEFAULT_BATCH_TIME_WINDOW = 0L;
        private boolean initialized = false;
        private static DirectSchedulerFactory instance = new DirectSchedulerFactory();
        private final Logger log = LoggerFactory.getLogger(this.getClass());
    ​
        protected Logger getLog() {
            return this.log;
        }
    ​
        protected DirectSchedulerFactory() {
        }
    
      ....

    仅从字面意思上理解 DirectSchedulerFactory 就是一个直接的 调度器创建工厂

    public static final String DEFAULT_INSTANCE_ID = "SIMPLE_NON_CLUSTERED";
    public static final String DEFAULT_SCHEDULER_NAME = "SimpleQuartzScheduler";

    开始两行中明确指明 这个直接的工厂 是没有实现分布式集群 而且预期返回 简单的调度器 实例

    再对比 StdSchedulerFactory的 源码:

    public class StdSchedulerFactory implements SchedulerFactory {
        public static final String PROPERTIES_FILE = "org.quartz.properties";
        public static final String PROP_SCHED_INSTANCE_NAME = "org.quartz.scheduler.instanceName";
        public static final String PROP_SCHED_INSTANCE_ID = "org.quartz.scheduler.instanceId";
        public static final String PROP_SCHED_INSTANCE_ID_GENERATOR_PREFIX = "org.quartz.scheduler.instanceIdGenerator";
        public static final String PROP_SCHED_INSTANCE_ID_GENERATOR_CLASS = "org.quartz.scheduler.instanceIdGenerator.class";
        public static final String PROP_SCHED_THREAD_NAME = "org.quartz.scheduler.threadName";
        public static final String PROP_SCHED_SKIP_UPDATE_CHECK = "org.quartz.scheduler.skipUpdateCheck";
        public static final String PROP_SCHED_BATCH_TIME_WINDOW = "org.quartz.scheduler.batchTriggerAcquisitionFireAheadTimeWindow";
        public static final String PROP_SCHED_MAX_BATCH_SIZE = "org.quartz.scheduler.batchTriggerAcquisitionMaxCount";
        public static final String PROP_SCHED_JMX_EXPORT = "org.quartz.scheduler.jmx.export";
        public static final String PROP_SCHED_JMX_OBJECT_NAME = "org.quartz.scheduler.jmx.objectName";
        public static final String PROP_SCHED_JMX_PROXY = "org.quartz.scheduler.jmx.proxy";
        public static final String PROP_SCHED_JMX_PROXY_CLASS = "org.quartz.scheduler.jmx.proxy.class";
        public static final String PROP_SCHED_RMI_EXPORT = "org.quartz.scheduler.rmi.export";
        public static final String PROP_SCHED_RMI_PROXY = "org.quartz.scheduler.rmi.proxy";
        public static final String PROP_SCHED_RMI_HOST = "org.quartz.scheduler.rmi.registryHost";
        public static final String PROP_SCHED_RMI_PORT = "org.quartz.scheduler.rmi.registryPort";
        public static final String PROP_SCHED_RMI_SERVER_PORT = "org.quartz.scheduler.rmi.serverPort";
        public static final String PROP_SCHED_RMI_CREATE_REGISTRY = "org.quartz.scheduler.rmi.createRegistry";
        public static final String PROP_SCHED_RMI_BIND_NAME = "org.quartz.scheduler.rmi.bindName";
        public static final String PROP_SCHED_WRAP_JOB_IN_USER_TX = "org.quartz.scheduler.wrapJobExecutionInUserTransaction";
        public static final String PROP_SCHED_USER_TX_URL = "org.quartz.scheduler.userTransactionURL";
        public static final String PROP_SCHED_IDLE_WAIT_TIME = "org.quartz.scheduler.idleWaitTime";
        public static final String PROP_SCHED_DB_FAILURE_RETRY_INTERVAL = "org.quartz.scheduler.dbFailureRetryInterval";
        public static final String PROP_SCHED_MAKE_SCHEDULER_THREAD_DAEMON = "org.quartz.scheduler.makeSchedulerThreadDaemon";
        public static final String PROP_SCHED_SCHEDULER_THREADS_INHERIT_CONTEXT_CLASS_LOADER_OF_INITIALIZING_THREAD = "org.quartz.scheduler.threadsInheritContextClassLoaderOfInitializer";
        public static final String PROP_SCHED_CLASS_LOAD_HELPER_CLASS = "org.quartz.scheduler.classLoadHelper.class";
        public static final String PROP_SCHED_JOB_FACTORY_CLASS = "org.quartz.scheduler.jobFactory.class";
        public static final String PROP_SCHED_JOB_FACTORY_PREFIX = "org.quartz.scheduler.jobFactory";
        public static final String PROP_SCHED_INTERRUPT_JOBS_ON_SHUTDOWN = "org.quartz.scheduler.interruptJobsOnShutdown";
        public static final String PROP_SCHED_INTERRUPT_JOBS_ON_SHUTDOWN_WITH_WAIT = "org.quartz.scheduler.interruptJobsOnShutdownWithWait";
        public static final String PROP_SCHED_CONTEXT_PREFIX = "org.quartz.context.key";
        public static final String PROP_THREAD_POOL_PREFIX = "org.quartz.threadPool";
        public static final String PROP_THREAD_POOL_CLASS = "org.quartz.threadPool.class";
        public static final String PROP_JOB_STORE_PREFIX = "org.quartz.jobStore";
        public static final String PROP_JOB_STORE_LOCK_HANDLER_PREFIX = "org.quartz.jobStore.lockHandler";
        public static final String PROP_JOB_STORE_LOCK_HANDLER_CLASS = "org.quartz.jobStore.lockHandler.class";
        public static final String PROP_TABLE_PREFIX = "tablePrefix";
        public static final String PROP_SCHED_NAME = "schedName";
        public static final String PROP_JOB_STORE_CLASS = "org.quartz.jobStore.class";
        public static final String PROP_JOB_STORE_USE_PROP = "org.quartz.jobStore.useProperties";
        public static final String PROP_DATASOURCE_PREFIX = "org.quartz.dataSource";
        public static final String PROP_CONNECTION_PROVIDER_CLASS = "connectionProvider.class";
    　　.....

    看起来明显区别是相对于 简单的调度器实例来说 它多出了好多常量

    从常量: PROPERTIES_FILE 中可以看出 它实际上是 对应的一个配置

    我们再返回去查看 第一章 .7 的properties 配置文件中的 可以配置的属性

    不难发现 其实我们可以设置的配置 再quartz的声明处 就在 这里

    它为我们创建了的调度器实现了各种复杂模式

    作为初始demo我现在不再深入它的具体实现

    继续进行代码分析:

    这里我们使用了 JobBulider 返回的是 JobDetail

    使用JobBulider 的newJob 方法 将 我们自实现的工作类当做参数传入

    追溯源码:

    ​public class JobBuilder {
        private JobKey key;
        private String description;
        private Class<? extends Job> jobClass;
        private boolean durability;
        private boolean shouldRecover;
        private JobDataMap jobDataMap = new JobDataMap();
      ...
        protected JobBuilder() {
        }
        public static JobBuilder newJob() {
            return new JobBuilder();
        }
        public static JobBuilder newJob(Class<? extends Job> jobClass) {
            JobBuilder b = new JobBuilder();
            b.ofType(jobClass);
            return b;
        }
      ...
         public JobBuilder ofType(Class<? extends Job> jobClazz) {
            this.jobClass = jobClazz;
            return this;
        }
      ...

    • 发现 JobBuilder 的静态方法中 实例了一个 JobBuilder的对象

    • 并调用了 ofType 将我们传入的自实现的工作类设置成这个对象的 成员属性

    • 再看 构造器 权限是 protected

    看上去感觉像是 单例模式 不能直接创建 对象~!!! 而是提供一个静态方法 返回一个当前类的一个实例

    区别就是 这个方法是个有参数的调用

    ok 我们现在就深入了解到这里 jobClass 具体什么时候使用 我们慢慢探索

    总体看起来 JobBuilder只是一个 充满 附加参数的 而且封装了Job的Pojo一样

    继续代码分析 发现:

    .withDescription("this is my first job01_HelloWorld ")  // 设置job相关描述

    没有什么可以赘述

     .withIdentity("hello job01_HelloWorld" ,"normal job01_HelloWorld") // 设置任务 名称和组名

    看一下 设置身份 它传入了两个 参数

    源码查看:

        public JobBuilder withIdentity(String name, String group) {
            this.key = new JobKey(name, group);
            return this;
        }

    翻看 JobKey 和Key<JobKey>的源码 :

    public class Key<T> implements Serializable, Comparable<Key<T>> {
        private static final long serialVersionUID = -7141167957642391350L;
        public static final String DEFAULT_GROUP = "DEFAULT";
        private final String name;
        private final String group;
    ...
       public static String createUniqueName(String group) {
            if (group == null) {
                group = "DEFAULT";
            }
    ​
            String n1 = UUID.randomUUID().toString();
            String n2 = UUID.nameUUIDFromBytes(group.getBytes()).toString();
            return String.format("%s-%s", n2.substring(24), n1);
        }

    实际上他只是为了达到 唯一的生成名称而创建的一个数据结构

    继续 再看:

    .build(); //创建 JobDetail

    源码:

    public JobDetail build() {
            JobDetailImpl job = new JobDetailImpl();
            job.setJobClass(this.jobClass);
            job.setDescription(this.description);
            if (this.key == null) {
                this.key = new JobKey(Key.createUniqueName((String)null), (String)null);
            }
    ​
            job.setKey(this.key);
            job.setDurability(this.durability);
            job.setRequestsRecovery(this.shouldRecover);
            if (!this.jobDataMap.isEmpty()) {
                job.setJobDataMap(this.jobDataMap);
            }
    ​
            return job;
        }

    创建了 JobDetail的一个子类 它的名字 (JobDetailImpl) 说明的是 JobDetail的一个实现

    他这样做的目的: 实际上 Quartz 只提供给我们 JobDetail里的一些可以用户自定义的属性设置接口 其他的Quartz负责了自动组装

    继续 分析代码:

     CronTrigger trigger = TriggerBuilder.newTrigger()
                    .withDescription("this is my first trigger") //设置 trigger 相关描述
                    .withIdentity("say hello trigger", "cron trigger") //设置 当前触发其 名字 和归属组名
                    .startAt(new Date()) // 设置任务启动时间
                    .withSchedule(CronScheduleBuilder.cronSchedule("0/10 * * * * ?"))
                    .build();

    翻看后发现与Job创建大同小异 不再赘述

    继续 分析代码 scheduleJob():

     scheduler.scheduleJob(jobDetail,trigger);

    我们一直翻看 StdScheduler 的实现 跟踪主要方法:

    跟踪到了QuartzScheduler 类中

    查看QuartzScheduler所属包名: package org.quartz.core;

    ok~ 到了核心类@!@

    package org.quartz.core;
    ...
    public class QuartzScheduler implements RemotableQuartzScheduler {
      ...
    public Date scheduleJob(JobDetail jobDetail, Trigger trigger) throws SchedulerException {
            this.validateState();
            if (jobDetail == null) {
                throw new SchedulerException("JobDetail cannot be null");
            } else if (trigger == null) {
                throw new SchedulerException("Trigger cannot be null");
            } else if (jobDetail.getKey() == null) {
                throw new SchedulerException("Job's key cannot be null");
            } else if (jobDetail.getJobClass() == null) {
                throw new SchedulerException("Job's class cannot be null");
            } else {
                OperableTrigger trig = (OperableTrigger)trigger;
                if (trigger.getJobKey() == null) {
                    trig.setJobKey(jobDetail.getKey());
                } else if (!trigger.getJobKey().equals(jobDetail.getKey())) {
                    throw new SchedulerException("Trigger does not reference given job!");
                }
    ​
                trig.validate();//验证trigger
                Calendar cal = null;
                if (trigger.getCalendarName() != null) {
                    cal = this.resources.getJobStore().retrieveCalendar(trigger.getCalendarName());
                }
    ​
                Date ft = trig.computeFirstFireTime(cal);
                if (ft == null) {
                    throw new SchedulerException("Based on configured schedule, the given trigger '" + trigger.getKey() + "' will never fire.");
                } else {
                    this.resources.getJobStore().storeJobAndTrigger(jobDetail, trig);
                    this.notifySchedulerListenersJobAdded(jobDetail);
                    this.notifySchedulerThread(trigger.getNextFireTime().getTime());
                    this.notifySchedulerListenersSchduled(trigger);
                    return ft;
                }
            }
        }

    一系列非空判断之后 有如下几行 :

     OperableTrigger trig = (OperableTrigger)trigger;
     trig.setJobKey(jobDetail.getKey());
    ...
     if (trigger.getCalendarName() != null) {
                    cal =           this.resources.getJobStore().retrieveCalendar(trigger.getCalendarName());
                }
    ​
      Date ft = trig.computeFirstFireTime(cal);
       this.resources.getJobStore().storeJobAndTrigger(jobDetail, trig);
                    this.notifySchedulerListenersJobAdded(jobDetail);
                    this.notifySchedulerThread(trigger.getNextFireTime().getTime());
                    this.notifySchedulerListenersSchduled(trigger);
                    return ft;

    • 第一步 对一个触发器 设置了 JobKey 实际上就绑定了 trigger和job之间的关系

    • 第二步 获取jobStore 翻看源码时 翻看 RAMJobStore 的retrieveCalendar()方法实现

    其实这里还没涉及到多个calendar 它的作用就是获取指定名称的日历

    • 第三步 获取第一次触发的时间

      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。

    • 第四步 "存储" 注册到JobStore

      通知调度器ListenersJob 添加 Job

    通知调度器线程 下次调用时间

    通知调度器工作安排

    ok ~ 其实 我们可以简单理解 主要作用就是将 trgger和job绑定 然后 quartz又通知了它的各个核心组件

    源码中:

    this.resources.getJobStore().storeJobAndTrigger(jobDetail, trig);

    追溯到JobStore 发现他有几个实现:

  • 

    "存储" 注册到JobStore的 方式区别也就在这里托盘而出:

    因为我们是RAMJobStore 我们查看源代码:

    public class RAMJobStore implements JobStore {
      ...
    public void storeJob(JobDetail newJob, boolean replaceExisting) throws ObjectAlreadyExistsException {
            JobWrapper jw = new JobWrapper((JobDetail)newJob.clone());
            boolean repl = false;
            Object var5 = this.lock;
            synchronized(this.lock) {
                if (this.jobsByKey.get(jw.key) != null) {
                    if (!replaceExisting) {
                        throw new ObjectAlreadyExistsException(newJob);
                    }
    ​
                    repl = true;
                }
    ​
                if (!repl) {
                    HashMap<JobKey, JobWrapper> grpMap = (HashMap)this.jobsByGroup.get(newJob.getKey().getGroup());
                    if (grpMap == null) {
                        grpMap = new HashMap(100);
                        this.jobsByGroup.put(newJob.getKey().getGroup(), grpMap);
                    }
    ​
                    grpMap.put(newJob.getKey(), jw);
                    this.jobsByKey.put(jw.key, jw);
                } else {
                    JobWrapper orig = (JobWrapper)this.jobsByKey.get(jw.key);
                    orig.jobDetail = jw.jobDetail;
                }
    ​
            }
        }

    它的实现是把内容放在了 一个Map中维护了 所以说再重启之后 这个map 并没有持久化到硬盘中 它的生命周期就在jvm关闭时丢失了

    再看一个不完全实现:

    public abstract class JobStoreSupport implements JobStore, Constants {
      ...
        public void storeJobAndTrigger(final JobDetail newJob, final OperableTrigger newTrigger) throws JobPersistenceException {
            this.executeInLock(this.isLockOnInsert() ? "TRIGGER_ACCESS" : null, new JobStoreSupport.VoidTransactionCallback() {
                public void executeVoid(Connection conn) throws JobPersistenceException {
                    JobStoreSupport.this.storeJob(conn, newJob, false);
                    JobStoreSupport.this.storeTrigger(conn, newTrigger, newJob, false, "WAITING", false, false);
                }
            });
        }
      ...
        protected void storeJob(Connection conn, JobDetail newJob, boolean replaceExisting) throws JobPersistenceException {
            boolean existingJob = this.jobExists(conn, newJob.getKey());
    ​
            try {
                if (existingJob) {
                    if (!replaceExisting) {
                        throw new ObjectAlreadyExistsException(newJob);
                    }
    ​
                    this.getDelegate().updateJobDetail(conn, newJob);
                } else {
                    this.getDelegate().insertJobDetail(conn, newJob);
                }
    ​
            } catch (IOException var6) {
                throw new JobPersistenceException("Couldn't store job: " + var6.getMessage(), var6);
            } catch (SQLException var7) {
                throw new JobPersistenceException("Couldn't store job: " + var7.getMessage(), var7);
            }
        }
      ...
        protected void storeTrigger(Connection conn, OperableTrigger newTrigger, JobDetail job, boolean replaceExisting, String state, boolean forceState, boolean recovering) throws JobPersistenceException {
            boolean existingTrigger = this.triggerExists(conn, newTrigger.getKey());
            if (existingTrigger && !replaceExisting) {
                throw new ObjectAlreadyExistsException(newTrigger);
            } else {
                try {
                    if (!forceState) {
                        boolean shouldBepaused = this.getDelegate().isTriggerGroupPaused(conn, newTrigger.getKey().getGroup());
                        if (!shouldBepaused) {
                            shouldBepaused = this.getDelegate().isTriggerGroupPaused(conn, "_$_ALL_GROUPS_PAUSED_$_");
                            if (shouldBepaused) {
                                this.getDelegate().insertPausedTriggerGroup(conn, newTrigger.getKey().getGroup());
                            }
                        }
    ​
                        if (shouldBepaused && (state.equals("WAITING") || state.equals("ACQUIRED"))) {
                            state = "PAUSED";
                        }
                    }
    ​
                    if (job == null) {
                        job = this.getDelegate().selectJobDetail(conn, newTrigger.getJobKey(), this.getClassLoadHelper());
                    }
    ​
                    if (job == null) {
                        throw new JobPersistenceException("The job (" + newTrigger.getJobKey() + ") referenced by the trigger does not exist.");
                    } else {
                        if (job.isConcurrentExectionDisallowed() && !recovering) {
                            state = this.checkBlockedState(conn, job.getKey(), state);
                        }
    ​
                        if (existingTrigger) {
                            this.getDelegate().updateTrigger(conn, newTrigger, state, job);
                        } else {
                            this.getDelegate().insertTrigger(conn, newTrigger, state, job);
                        }
    ​
                    }
                } catch (Exception var10) {
                    throw new JobPersistenceException("Couldn't store trigger '" + newTrigger.getKey() + "' for '" + newTrigger.getJobKey() + "' job:" + var10.getMessage(), var10);
                }
            }
        }
    ​
    ​

    其中的updateJobDetail 翻看源码实际上是将内容存储到了 数据库中

    这其实就是jdbc 方式的原理

    现在话题拉回来

    继续 分析代码:

    我们完成了所有的创建注册绑定操作 万事俱备只欠东风了

    启动:

    // 6 启动 调度器
    scheduler.start();

    源码:

    public void start() throws SchedulerException {
            if (!this.shuttingDown && !this.closed) {
                this.notifySchedulerListenersStarting();
                if (this.initialStart == null) {
                    this.initialStart = new Date();
                    this.resources.getJobStore().schedulerStarted();
                    this.startPlugins();
                } else {
                    this.resources.getJobStore().schedulerResumed();
                }
    ​
                this.schedThread.togglePause(false);//设置 不暂停
                this.getLog().info("Scheduler " + this.resources.getUniqueIdentifier() + " started.");
                this.notifySchedulerListenersStarted();// 提醒 调度器的监听 启动
            } else {
                throw new SchedulerException("The Scheduler cannot be restarted after shutdown() has been called.");
            }
        }

    初始化JobStore源码分析:

            // 判断初始化标识    保证jobStore
            if (this.initialStart == null) { // 没有初始化过: 进行初始化
                    this.initialStart = new Date();
                    this.resources.getJobStore().schedulerStarted();
                    this.startPlugins();
                } else { // 已经初始化过  进行 恢复
                    this.resources.getJobStore().schedulerResumed();
                }

    public abstract class JobStoreSupport implements JobStore, Constants {
    ...
    public void schedulerStarted() throws SchedulerException {
            if (this.isClustered()) {//判断是否是是集群
                this.clusterManagementThread = new JobStoreSupport.ClusterManager();
                if (this.initializersLoader != null) {
                    this.clusterManagementThread.setContextClassLoader(this.initializersLoader);
                }
    ​
                this.clusterManagementThread.initialize();
            } else { // 不是集群的话
                try {
                    this.recoverJobs();// 恢复 工作
                } catch (SchedulerException var2) {
                    throw new SchedulerConfigException("Failure occured during job recovery.", var2);
                }
            }
    ​
            this.misfireHandler = new JobStoreSupport.MisfireHandler();
            if (this.initializersLoader != null) {
                this.misfireHandler.setContextClassLoader(this.initializersLoader);
            }
    ​
            this.misfireHandler.initialize();
            this.schedulerRunning = true;
            this.getLog().debug("JobStore background threads started (as scheduler was started).");
        }
      ...
         //  恢复 工作:
        // 将恢复任何失败的工作和丢失了触发的工作，并根据需要清理数据存储
        protected void recoverJobs() throws JobPersistenceException {
            this.executeInNonManagedTXLock("TRIGGER_ACCESS", new JobStoreSupport.VoidTransactionCallback() {
                public void executeVoid(Connection conn) throws JobPersistenceException {
                    JobStoreSupport.this....(conn);//恢复job
                }
            }, (JobStoreSupport.TransactionValidator)null);
        }
      ...
    
       protected void recoverJobs(Connection conn) throws JobPersistenceException {
            try {
                int rows = this.getDelegate().updateTriggerStatesFromOtherStates(conn, "WAITING", "ACQUIRED", "BLOCKED");
                rows += this.getDelegate().updateTriggerStatesFromOtherStates(conn, "PAUSED", "PAUSED_BLOCKED", "PAUSED_BLOCKED");
                this.getLog().info("Freed " + rows + " triggers from 'acquired' / 'blocked' state.");
                this.recoverMisfiredJobs(conn, true);
                List<OperableTrigger> recoveringJobTriggers = this.getDelegate().selectTriggersForRecoveringJobs(conn);
                this.getLog().info("Recovering " + recoveringJobTriggers.size() + " jobs that were in-progress at the time of the last shut-down.");
                Iterator i$ = recoveringJobTriggers.iterator();
    ​
                while(i$.hasNext()) {
                    OperableTrigger recoveringJobTrigger = (OperableTrigger)i$.next();
                    if (this.jobExists(conn, recoveringJobTrigger.getJobKey())) {
                        recoveringJobTrigger.computeFirstFireTime((Calendar)null);
                        this.storeTrigger(conn, recoveringJobTrigger, (JobDetail)null, false, "WAITING", false, true);
                    }
                }
    ​
                this.getLog().info("Recovery complete.");
                List<TriggerKey> cts = this.getDelegate().selectTriggersInState(conn, "COMPLETE");
                Iterator i$ = cts.iterator();
    ​
                while(i$.hasNext()) {
                    TriggerKey ct = (TriggerKey)i$.next();
                    this.removeTrigger(conn, ct);
                }
    ​
                this.getLog().info("Removed " + cts.size() + " 'complete' triggers.");
                int n = this.getDelegate().deleteFiredTriggers(conn);
                this.getLog().info("Removed " + n + " stale fired job entries.");
            } catch (JobPersistenceException var7) {
                throw var7;
            } catch (Exception var8) {
                throw new JobPersistenceException("Couldn't recover jobs: " + var8.getMessage(), var8);
            }
        } 

    初始JobStore时 恢复相关: 将 失败标识的 或者 丢失触发的 工作 进行一个找回 并设置到 调度器触发工作日程中

    分析:

      this.schedThread.togglePause(false);

    探索:

     // 设置主处理循环在下一个可能的点暂停。
    void togglePause(boolean pause) {
            Object var2 = this.sigLock;
            synchronized(this.sigLock) {
                this.paused = pause;
                if (this.paused) {
                    this.signalSchedulingChange(0L);
                } else {
                    this.sigLock.notifyAll(); // 唤醒所有等待线程
                }
    ​
            }
        }
    ...
      //通知主要处理循环，已经进行了调度的改变
        public void signalSchedulingChange(long candidateNewNextFireTime) {
            Object var3 = this.sigLock;
            synchronized(this.sigLock) {
                this.signaled = true;
                this.signaledNextFireTime = candidateNewNextFireTime;
                this.sigLock.notifyAll();//中断在等待时间到达时可能发生的任何睡眠线程
            }
        }