初始化流程
最好结合上篇文章的例子来看，对应于使用Quartz的第一个和第二个步骤，创建StdSchedulerFactory和StdScheduler。
SchedulerFacotory，顾名思义，就是生产Scheduler实例的工厂类。下面的代码逻辑这么多，就是为了创建一个Scheduler实例。
初始化流程
源码解析
创建SchedulerFacotory
SchedulerFacotory是一个接口，它有两个实现:
StdSchedulerFacotory通过配置文件来设置Scheduler的各项参数
DirectSchedulerFactory主要通过硬编码来设置Scheduler的各项参数。
我们一般使用StdSchedulerFacotory，后者需要对Scheduler有很好的理解。quartz.properties里面的配置都对应到这个StdSchedulerFactory中，所以对某个配置不明白已经该配置的默认值可以看StdSchedulerFactory中获取配置的代码。
- 构造方法
/**
* 上篇的例子我们是通过这个构造方法创建实例，读取配置文件延迟到了getScheduler()方法
*/
public StdSchedulerFactory() {
}
/**
* Create a StdSchedulerFactory that has been initialized via
* {@link #initialize(Properties)}.
*
* @see #initialize(Properties)
*/
public StdSchedulerFactory(Properties props) throws SchedulerException {
initialize(props);
}
/**
* Create a StdSchedulerFactory that has been initialized via
* {@link #initialize(String)}.
*
* @see #initialize(String)
*/
public StdSchedulerFactory(String fileName) throws SchedulerException {
initialize(fileName);
}
- getScheduler()方法
/**
*
* 加载quartz.properties
* 初始化StdScheduler
*
*/
public Scheduler getScheduler() throws SchedulerException {
// 加载quartz.properties
if (cfg == null) {
initialize();
}
// 单例的SchedulerRepository实例
SchedulerRepository schedRep = SchedulerRepository.getInstance();
// 如果已经有类似的Scheduler启动了，就不用再创建了
Scheduler sched = schedRep.lookup(getSchedulerName());
if (sched != null) {
if (sched.isShutdown()) {
schedRep.remove(getSchedulerName());
} else {
return sched;
}
}
// 初始化StdScheduler
sched = instantiate();
return sched;
}
创建Scheduler
- instantiate()
创建资源的逻辑基本都在这个方法里面了，方法很长，有接近800行，"..."表示此处减去了一些我认为对理解创建流程不是很重要的代码。
/**
* 创建ClassLoadHelper，以便根据配置文件提供的类名去创建实例
* 获取quartz.properties的配置值
* 创建ClassLoadHelper，以便根据配置文件提供的类名去创建实例
* 创建JobFactory
* 根据PropertiesParser创建ThreadPool
* 根据PropertiesParser创建JobStore
* 根据PropertiesParser创建DataSource
* 根据PropertiesParser创建SchedulerPlugin
* 根据PropertiesParser创建Listeners
* 根据PropertiesParser创建ThreadExecutor
* 根据PropertiesParser创建JobRunShellFactory
* 创建QuartzSchedulerResources
* ThreadPool.initialize();
* new QuartzScheduler();
* StdScheduler的所有方法都委托给了QuartzScheduler；
* @return
* @throws SchedulerException
*/
private Scheduler instantiate() throws SchedulerException {
...
JobStore js = null;
ThreadPool tp = null;
QuartzScheduler qs = null;
DBConnectionManager dbMgr = null;
String instanceIdGeneratorClass = null;
Properties tProps = null;
String userTXLocation = null;
boolean wrapJobInTx = false;
boolean autoId = false;
long idleWaitTime = -1;
long dbFailureRetry = 15000L; // 15 secs
String classLoadHelperClass;
String jobFactoryClass;
ThreadExecutor threadExecutor;
SchedulerRepository schedRep = SchedulerRepository.getInstance();
// 获取quartz.properties的配置值
String schedName = cfg.getStringProperty(PROP_SCHED_INSTANCE_NAME,
"QuartzScheduler");
...
// 创建ClassLoadHelper，以便根据配置文件提供的类名去创建实例
ClassLoadHelper loadHelper = null;
try {
loadHelper = (ClassLoadHelper) loadClass(classLoadHelperClass)
.newInstance();
} catch (Exception e) {
throw new SchedulerConfigException(
"Unable to instantiate class load helper class: "
+ e.getMessage(), e);
}
loadHelper.initialize();
// If Proxying to remote JMX scheduler, short-circuit here...
// TODO：代理是做什么的 和 RemoteMBeanScheduler的使用
if (jmxProxy) {
...
}
// 创建JobFactory
JobFactory jobFactory = null;
if(jobFactoryClass != null) {
try {
jobFactory = (JobFactory) loadHelper.loadClass(jobFactoryClass)
.newInstance();
} catch (Exception e) {
throw new SchedulerConfigException(
"Unable to instantiate JobFactory class: "
+ e.getMessage(), e);
}
tProps = cfg.getPropertyGroup(PROP_SCHED_JOB_FACTORY_PREFIX, true);
try {
setBeanProps(jobFactory, tProps);
} catch (Exception e) {
initException = new SchedulerException("JobFactory class '"
+ jobFactoryClass + "' props could not be configured.", e);
throw initException;
}
}
...
// 根据PropertiesParser创建ThreadPool
String tpClass = cfg.getStringProperty(PROP_THREAD_POOL_CLASS, SimpleThreadPool.class.getName());
if (tpClass == null) {
initException = new SchedulerException("ThreadPool class not specified. ");
throw initException;
}
try {
tp = (ThreadPool) loadHelper.loadClass(tpClass).newInstance();
} catch (Exception e) {
initException = new SchedulerException("ThreadPool class '"
+ tpClass + "' could not be instantiated.", e);
throw initException;
}
tProps = cfg.getPropertyGroup(PROP_THREAD_POOL_PREFIX, true);
try {
setBeanProps(tp, tProps);
} catch (Exception e) {
initException = new SchedulerException("ThreadPool class '"
+ tpClass + "' props could not be configured.", e);
throw initException;
}
// 根据PropertiesParser创建JobStore
String jsClass = cfg.getStringProperty(PROP_JOB_STORE_CLASS,
RAMJobStore.class.getName());
if (jsClass == null) {
initException = new SchedulerException(
"JobStore class not specified. ");
throw initException;
}
try {
js = (JobStore) loadHelper.loadClass(jsClass).newInstance();
} catch (Exception e) {
initException = new SchedulerException("JobStore class '" + jsClass
+ "' could not be instantiated.", e);
throw initException;
}
SchedulerDetailsSetter.setDetails(js, schedName, schedInstId);
tProps = cfg.getPropertyGroup(PROP_JOB_STORE_PREFIX, true, new String[] {PROP_JOB_STORE_LOCK_HANDLER_PREFIX});
try {
setBeanProps(js, tProps);
} catch (Exception e) {
initException = new SchedulerException("JobStore class '" + jsClass
+ "' props could not be configured.", e);
throw initException;
}
// 持久化的JobStore处理逻辑
if (js instanceof JobStoreSupport) {
// Install custom lock handler (Semaphore)
String lockHandlerClass = cfg.getStringProperty(PROP_JOB_STORE_LOCK_HANDLER_CLASS);
if (lockHandlerClass != null) {
try {
Semaphore lockHandler = (Semaphore)loadHelper.loadClass(lockHandlerClass).newInstance();
tProps = cfg.getPropertyGroup(PROP_JOB_STORE_LOCK_HANDLER_PREFIX, true);
// If this lock handler requires the table prefix, add it to its properties.
if (lockHandler instanceof TablePrefixAware) {
tProps.setProperty(
PROP_TABLE_PREFIX, ((JobStoreSupport)js).getTablePrefix());
tProps.setProperty(
PROP_SCHED_NAME, schedName);
}
try {
setBeanProps(lockHandler, tProps);
} catch (Exception e) {
initException = new SchedulerException("JobStore LockHandler class '" + lockHandlerClass
+ "' props could not be configured.", e);
throw initException;
}
((JobStoreSupport)js).setLockHandler(lockHandler);
getLog().info("Using custom data access locking (synchronization): " + lockHandlerClass);
} catch (Exception e) {
initException = new SchedulerException("JobStore LockHandler class '" + lockHandlerClass
+ "' could not be instantiated.", e);
throw initException;
}
}
}
// Set up any DataSources
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// 根据PropertiesParser创建DataSource
String[] dsNames = cfg.getPropertyGroups(PROP_DATASOURCE_PREFIX);
for (int i = 0; i < dsNames.length; i++) {
...
}
// 根据PropertiesParser创建SchedulerPlugin
String[] pluginNames = cfg.getPropertyGroups(PROP_PLUGIN_PREFIX);
SchedulerPlugin[] plugins = new SchedulerPlugin[pluginNames.length];
for (int i = 0; i < pluginNames.length; i++) {
...
}
// 根据PropertiesParser创建Listeners
Class[] strArg = new Class[] { String.class };
String[] jobListenerNames = cfg.getPropertyGroups(PROP_JOB_LISTENER_PREFIX);
JobListener[] jobListeners = new JobListener[jobListenerNames.length];
for (int i = 0; i < jobListenerNames.length; i++) {
...
}
String[] triggerListenerNames = cfg.getPropertyGroups(PROP_TRIGGER_LISTENER_PREFIX);
TriggerListener[] triggerListeners = new TriggerListener[triggerListenerNames.length];
for (int i = 0; i < triggerListenerNames.length; i++) {
...
}
boolean tpInited = false;
boolean qsInited = false;
// 根据PropertiesParser创建ThreadExecutor
String threadExecutorClass = cfg.getStringProperty(PROP_THREAD_EXECUTOR_CLASS);
if (threadExecutorClass != null) {
tProps = cfg.getPropertyGroup(PROP_THREAD_EXECUTOR, true);
try {
threadExecutor = (ThreadExecutor) loadHelper.loadClass(threadExecutorClass).newInstance();
log.info("Using custom implementation for ThreadExecutor: " + threadExecutorClass);
setBeanProps(threadExecutor, tProps);
} catch (Exception e) {
initException = new SchedulerException(
"ThreadExecutor class '" + threadExecutorClass + "' could not be instantiated.", e);
throw initException;
}
} else {
log.info("Using default implementation for ThreadExecutor");
threadExecutor = new DefaultThreadExecutor();
}
// Fire everything up
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
try {
JobRunShellFactory jrsf = null; // Create correct run-shell factory...
if (userTXLocation != null) {
UserTransactionHelper.setUserTxLocation(userTXLocation);
}
if (wrapJobInTx) {
jrsf = new JTAJobRunShellFactory();
} else {
jrsf = new JTAAnnotationAwareJobRunShellFactory();
}
if (autoId) {
try {
schedInstId = DEFAULT_INSTANCE_ID;
if (js.isClustered()) {
schedInstId = instanceIdGenerator.generateInstanceId();
}
} catch (Exception e) {
getLog().error("Couldn't generate instance Id!", e);
throw new IllegalStateException("Cannot run without an instance id.");
}
}
if (js.getClass().getName().startsWith("org.terracotta.quartz")) {
try {
String uuid = (String) js.getClass().getMethod("getUUID").invoke(js);
if(schedInstId.equals(DEFAULT_INSTANCE_ID)) {
schedInstId = "TERRACOTTA_CLUSTERED,node=" + uuid;
if (jmxObjectName == null) {
jmxObjectName = QuartzSchedulerResources.generateJMXObjectName(schedName, schedInstId);
}
} else if(jmxObjectName == null) {
jmxObjectName = QuartzSchedulerResources.generateJMXObjectName(schedName, schedInstId + ",node=" + uuid);
}
} catch(Exception e) {
throw new RuntimeException("Problem obtaining node id from TerracottaJobStore.", e);
}
if(null == cfg.getStringProperty(PROP_SCHED_JMX_EXPORT)) {
jmxExport = true;
}
}
if (js instanceof JobStoreSupport) {
JobStoreSupport jjs = (JobStoreSupport)js;
jjs.setDbRetryInterval(dbFailureRetry);
if(threadsInheritInitalizersClassLoader)
jjs.setThreadsInheritInitializersClassLoadContext(threadsInheritInitalizersClassLoader);
jjs.setThreadExecutor(threadExecutor);
}
// 创建QuartzSchedulerResources
QuartzSchedulerResources rsrcs = new QuartzSchedulerResources();
rsrcs.setName(schedName);
rsrcs.setThreadName(threadName);
rsrcs.setInstanceId(schedInstId);
rsrcs.setJobRunShellFactory(jrsf);
rsrcs.setMakeSchedulerThreadDaemon(makeSchedulerThreadDaemon);
rsrcs.setThreadsInheritInitializersClassLoadContext(threadsInheritInitalizersClassLoader);
rsrcs.setBatchTimeWindow(batchTimeWindow);
rsrcs.setMaxBatchSize(maxBatchSize);
rsrcs.setInterruptJobsOnShutdown(interruptJobsOnShutdown);
rsrcs.setInterruptJobsOnShutdownWithWait(interruptJobsOnShutdownWithWait);
rsrcs.setJMXExport(jmxExport);
rsrcs.setJMXObjectName(jmxObjectName);
if (managementRESTServiceEnabled) {
ManagementRESTServiceConfiguration managementRESTServiceConfiguration = new ManagementRESTServiceConfiguration();
managementRESTServiceConfiguration.setBind(managementRESTServiceHostAndPort);
managementRESTServiceConfiguration.setEnabled(managementRESTServiceEnabled);
rsrcs.setManagementRESTServiceConfiguration(managementRESTServiceConfiguration);
}
if (rmiExport) {
rsrcs.setRMIRegistryHost(rmiHost);
rsrcs.setRMIRegistryPort(rmiPort);
rsrcs.setRMIServerPort(rmiServerPort);
rsrcs.setRMICreateRegistryStrategy(rmiCreateRegistry);
rsrcs.setRMIBindName(rmiBindName);
}
SchedulerDetailsSetter.setDetails(tp, schedName, schedInstId);
rsrcs.setThreadExecutor(threadExecutor);
threadExecutor.initialize();
rsrcs.setThreadPool(tp);
if(tp instanceof SimpleThreadPool) {
if(threadsInheritInitalizersClassLoader)
((SimpleThreadPool)tp).setThreadsInheritContextClassLoaderOfInitializingThread(threadsInheritInitalizersClassLoader);
}
tp.initialize();
tpInited = true;
rsrcs.setJobStore(js);
// add plugins
for (int i = 0; i < plugins.length; i++) {
rsrcs.addSchedulerPlugin(plugins[i]);
}
qs = new QuartzScheduler(rsrcs, idleWaitTime, dbFailureRetry);
qsInited = true;
// Create Scheduler ref...
Scheduler scheduler = instantiate(rsrcs, qs);
// set job factory if specified
if(jobFactory != null) {
qs.setJobFactory(jobFactory);
}
// Initialize plugins now that we have a Scheduler instance.
for (int i = 0; i < plugins.length; i++) {
plugins[i].initialize(pluginNames[i], scheduler, loadHelper);
}
// add listeners
for (int i = 0; i < jobListeners.length; i++) {
qs.getListenerManager().addJobListener(jobListeners[i], EverythingMatcher.allJobs());
}
for (int i = 0; i < triggerListeners.length; i++) {
qs.getListenerManager().addTriggerListener(triggerListeners[i], EverythingMatcher.allTriggers());
}
// set scheduler context data...
for(Object key: schedCtxtProps.keySet()) {
String val = schedCtxtProps.getProperty((String) key);
scheduler.getContext().put((String)key, val);
}
// fire up job store, and runshell factory
js.setInstanceId(schedInstId);
js.setInstanceName(schedName);
js.setThreadPoolSize(tp.getPoolSize());
js.initialize(loadHelper, qs.getSchedulerSignaler());
jrsf.initialize(scheduler);
qs.initialize();
getLog().info(
"Quartz scheduler '" + scheduler.getSchedulerName()
+ "' initialized from " + propSrc);
getLog().info("Quartz scheduler version: " + qs.getVersion());
// prevents the repository from being garbage collected
qs.addNoGCObject(schedRep);
// prevents the db manager from being garbage collected
if (dbMgr != null) {
qs.addNoGCObject(dbMgr);
}
schedRep.bind(scheduler);
return scheduler;
}
catch(SchedulerException e) {
shutdownFromInstantiateException(tp, qs, tpInited, qsInited);
throw e;
}
catch(RuntimeException re) {
shutdownFromInstantiateException(tp, qs, tpInited, qsInited);
throw re;
}
catch(Error re) {
shutdownFromInstantiateException(tp, qs, tpInited, qsInited);
throw re;
}
}
系列文章
- Quartz 源码解析(一) —— 基本介绍
- Quartz 源码解析(二) —— Scheduler的初始化
- Quartz 源码解析(三) —— JobDetail、Trigger和它们的Builder
- Quartz 源码解析(四) —— QuartzScheduler和Listener事件监听
- Quartz 源码解析(五) —— QuartzSchedulerThread
- Quartz 源码解析(六) —— 解析Cron表达式