Quartz学习--二 Hello Quartz! 和源码分析

三. Hello Quartz!

我会跟着 第一章 6.2 的图来 进行同步代码编写- 简单入门示例: 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>--> 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");
    }
    } 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 执行结果:
  • 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)


    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)


    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


    }
    } 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
    }
    }