本人在上文中提到，连接器实现了两种事件依赖的机制 ，其一是我们手动操作连接器实例时；其二是由连接器的自动更新机制
上文中分析了连接器的自动更新机制，即定时器执行定时任务
那么，如果我们手动操作连接器实例时，是怎么发出事件更新连接器实例的呢
通过eclipse开发工具，追踪调用ChangeDetector接口的detect()方法的方法
ChangeDetectorTask类的run方法里面调用我们再上文中已经分析了，其他方法便是ConnectorCoordinatorImpl实例对象的方法
即ConnectorCoordinatorImpl实例对象的如下方法，分别调用了ChangeDetector接口的detect()方法
/**
* 移除连接器实例
* Removes this {@link Connector} instance. Halts traversals,
* removes the Connector instance from the known connectors,
* and removes the Connector's on-disk representation.
*/
/* @Override */
public void removeConnector() {
synchronized(this) {
resetBatch();
if (instanceInfo != null) {
instanceInfo.removeConnector();
}
}
// This must not be called while holding the lock.
changeDetector.detect();
} /**
* 重启遍历
* Retraverses the {@link Connector}'s content from scratch.
* Halts any traversal in progress and removes any saved traversal state,
* forcing the Connector to retraverse the Repository from its start.
*/
/* @Override */
public void restartConnectorTraversal() throws ConnectorNotFoundException {
// To avoid deadlock, this method calls InstanceInfo's getters and setters,
// rather than the local ones.
synchronized(this) {
resetBatch(); // Halt any traversal.
getInstanceInfo().setConnectorState(null); // Discard the checkpoint. // If Schedule was 'run-once', re-enable it to run again. But watch out -
// empty disabled Schedules could look a bit like a run-once Schedule.
Schedule schedule = getInstanceInfo().getConnectorSchedule();
if (schedule != null && schedule.isDisabled() &&
schedule.getRetryDelayMillis() == -1 &&
schedule.nextScheduledInterval() != -1) {
schedule.setDisabled(false);
getInstanceInfo().setConnectorSchedule(schedule);
}
} // TODO: Remove this if we switch completely to JDBC PersistentStore.
// FileStore doesn't notice the deletion of a file that did not exist.
if (lister != null) {
connectorCheckpointChanged(null);
} // This must not be called while holding the lock.
changeDetector.detect();
} /**
* 设置配置信息
* Sets the {@link Configuration} for this {@link ConnectorCoordinator}.
* If this {@link ConnectorCoordinator} supports persistence this will
* persist the new Configuration.
*/
/* @Override */
public ConfigureResponse setConnectorConfiguration(TypeInfo newTypeInfo,
Configuration configuration, Locale locale, boolean update)
throws ConnectorNotFoundException, ConnectorExistsException,
InstantiatorException {
LOGGER.info("Configuring connector " + name);
String typeName = newTypeInfo.getConnectorTypeName();
Preconditions.checkArgument(typeName.equals(configuration.getTypeName()),
"TypeInfo must match Configuration type");
ConfigureResponse response = null;
synchronized(this) {
resetBatch();
if (instanceInfo != null) {
if (!update) {
throw new ConnectorExistsException();
}
if (typeName.equals(typeInfo.getConnectorTypeName())) {
configuration =
new Configuration(configuration, getConnectorConfiguration());
response = resetConfig(instanceInfo.getConnectorDir(), typeInfo,
configuration, locale);
} else {
// An existing connector is being given a new type - drop then add.
// TODO: This shouldn't be called from within the synchronized block
// because it will kick the change detector.
removeConnector();
response = createNewConnector(newTypeInfo, configuration, locale);
if (response != null) {
// TODO: We need to restore original Connector config. This is
// necessary once we allow update a Connector with new ConnectorType.
// However, when doing so consider: createNewConnector could have
// thrown InstantiatorException as well. Also, you need to kick
// the changeDetector (but not in this synchronized block).
LOGGER.severe("Failed to update Connector configuration.");
// + " Restoring original Connector configuration.");
}
}
} else {
if (update) {
throw new ConnectorNotFoundException();
}
response = createNewConnector(newTypeInfo, configuration, locale);
}
}
if (response == null) {
// This must not be called while holding the lock.
changeDetector.detect();
} else {
return new ExtendedConfigureResponse(response, configuration.getXml());
}
return response;
} /**
* 设置定时调度
* Sets the traversal {@link Schedule} for the {@link Connector}.
*
* @param connectorSchedule Schedule to store or null to unset any existing
* Schedule.
* @throws ConnectorNotFoundException if the connector is not found
*/
/* @Override */
public void setConnectorSchedule(Schedule connectorSchedule)
throws ConnectorNotFoundException {
synchronized(this) {
// Persistently store the new schedule.
getInstanceInfo().setConnectorSchedule(connectorSchedule);
}
// This must not be called while holding the lock.
changeDetector.detect();
}
接下来ChangeDetector接口的detect()方法其实又调用了自身的实现ConnectorCoordinatorImpl实例对象的实现ChangeHandler接口的方法
ConnectorCoordinatorImpl-->ChangeDetector的detect()-->ChangeListener的相关方法-->ChangeHandler(ConnectorCoordinatorImpl实例对象)的相关方法
所以手动操作与自动更新机制实际上是殊途同归，最后都是调用了ChangeHandler(ConnectorCoordinatorImpl实例对象)的相关方法
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