de.aristaflow.adept2.core.eventmanager.fileevents

Class FileEventSource

java.lang.Object

de.aristaflow.adept2.core.eventmanager.common.AbstractEventSource<FileEvent>

de.aristaflow.adept2.core.eventmanager.fileevents.FileEventSource

All Implemented Interfaces:

EventSource<FileEvent>, PollingFileSource, PollingSource<FileEvent>, java.lang.Runnable

Direct Known Subclasses:

FileEventActivitySource

public class FileEventSource
extends AbstractEventSource<FileEvent>
implements PollingFileSource

A source for events based on files in a specific folder (configured). This folder is checked regularly and any file (or directory) found is notified as file event to the corresponding registered event handlers.

Author:

Ulrich Kreher, Marco Waimer

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	FileEventSource.FileEventFilter A file filter applying the configured restrictions for the file event source to the searched directory.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.net.URI[]	eventManagerURIs The event manager URIs to provide to the created events.
protected java.lang.String	filterName Regex for filtering on the file name or null if not set.
protected boolean	isLockFile Whether the event occurs on the lock file or not.
protected boolean	lockFileEvent Whether the lock file should also be part of the event.
protected java.lang.String	lockSuffix The suffix that is used by the handler to lock files.
protected java.util.regex.Pattern	namePattern Pattern for filtering on the file name or null if not set.
protected java.lang.Long	pollTime The time in milliseconds this event source polls its data source.
protected java.net.URL	searchPath The path to the directory which causes an event when a new file is inserted.
protected boolean	skipDirectories Whether directories should be skipped.
protected boolean	skipFiles Whether files should be skipped.
protected boolean	skipLocked Whether locked files should be skipped.
protected java.lang.Long	startPoint The start point (in milliseconds) this event should start polling.

Fields inherited from class de.aristaflow.adept2.core.eventmanager.common.AbstractEventSource

eventType, handlerList, id, lock, logger, sourceType, thread, threadLock

Fields inherited from interface de.aristaflow.adept2.model.events.sources.PollingFileSource

CONF_FILENAME_FILTER, CONF_IS_LOCK_FILE, CONF_LOCK_FILE_EVENT, CONF_LOCK_SUFFIX, CONF_SEARCH_DIRECTORY, CONF_SKIP_DIRECTORIES, CONF_SKIP_FILES, CONF_SKIP_LOCKED

Fields inherited from interface de.aristaflow.adept2.model.events.sources.PollingSource

CONF_POLL_TIME, CONF_START_TIME

Constructor Summary

Constructors

Constructor and Description
FileEventSource(Configuration conf, EventManager eventManager, Registry registry) Default constructor for a plugin of an EventManager called by a service registry.

Method Summary

Modifier and Type	Method and Description
void	checkForAndHandleEvent() Checks for an event and handles it (usually by using AbstractEventSource.forwardEvent(Event, boolean, boolean)).
protected FileEvent	createFileEvent(java.io.File file) Deprecated. Use createFileEvent(Path) instead.
protected FileEvent	createFileEvent(java.nio.file.Path path) Creates a FileEvent for the designated path.
protected FileEvent	createLockFileEvent(java.io.File file, java.io.File lockFile) Deprecated. Use createLockFileEvent(Path, Path) instead.
protected LockFileEvent	createLockFileEvent(java.nio.file.Path path, java.nio.file.Path lockPath) Creates a FileEvent for the designated file and its lock file.
long	getPollTime() Gets the time in milliseconds this event source polls, more precisely, the time span between two polls.
long	getStartTime() Gets the absolute time in milliseconds since midnight, January 1, 1970 UTC when this polling source should start polling.
void	init() Initialises this polling source.
protected boolean	nextHandler(FileEvent event, boolean consumed, boolean concurrent) This method is called right before an event is offered to the next handler.
protected void	setConfiguration(Configuration conf, boolean completed) Sets the internal fields according to the values of the designated configuration.
void	setConfiguration(Configuration conf, java.lang.String id) Sets the (additional) configuration of this event source and its ID.
void	terminate() Terminates this polling source.
protected void	verifyConfigurationValues() This method verifies the configuration values that have been set yet.

Methods inherited from class de.aristaflow.adept2.core.eventmanager.common.AbstractEventSource

addAll, addedHandlerLocked, addedHandlerLocked, addHandler, createPattern, forwardEvent, getEventHandler, getHierarchicalSourceName, getID, getType, maskedInterrupt, maskInterrupt, removeHandler, removingHandlerLocked, replaceValueParams, run, unmaskInterrupt

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface de.aristaflow.adept2.model.events.sources.EventSource

addAll, addHandler, getEventHandler, getHierarchicalSourceName, getID, getType, removeHandler

Methods inherited from interface java.lang.Runnable

run

Field Detail

pollTime

protected java.lang.Long pollTime

The time in milliseconds this event source polls its data source.

startPoint

protected java.lang.Long startPoint

The start point (in milliseconds) this event should start polling.

searchPath

protected java.net.URL searchPath

The path to the directory which causes an event when a new file is inserted.

filterName

protected java.lang.String filterName

Regex for filtering on the file name or null if not set.

namePattern

protected java.util.regex.Pattern namePattern

Pattern for filtering on the file name or null if not set.

skipDirectories

protected boolean skipDirectories

Whether directories should be skipped.

skipFiles

protected boolean skipFiles

Whether files should be skipped.

skipLocked

protected boolean skipLocked

Whether locked files should be skipped.

lockSuffix

protected java.lang.String lockSuffix

The suffix that is used by the handler to lock files. Keep in sync with the corresponding event handler marking files by creating lock files so that the locked files will be skipped.

lockFileEvent

protected boolean lockFileEvent

Whether the lock file should also be part of the event.

isLockFile

protected boolean isLockFile

Whether the event occurs on the lock file or not.

eventManagerURIs

protected final java.net.URI[] eventManagerURIs

The event manager URIs to provide to the created events.

Constructor Detail

FileEventSource

public FileEventSource(Configuration conf,
                       EventManager eventManager,
                       Registry registry)
                throws ConfigurationException

Default constructor for a plugin of an EventManager called by a service registry.

Note that this constructor calls setConfiguration(Configuration, boolean); subclasses may not be fully initialised at this point.

Parameters:

conf - The configuration as provided from the registry.

eventManager - The event manager this event source is a plugin of.

registry - The registry of this plugin.

Throws:

ConfigurationException - If the configuration is not valid for a PollingFileSource, a ConfigurationException will be thrown.

Method Detail

setConfiguration

protected void setConfiguration(Configuration conf,
                                boolean completed)
                         throws ConfigurationException

Sets the internal fields according to the values of the designated configuration. Note that this method is called from the constructor and therefore this object may not be fully initialised!

Parameters:

conf - The configuration from which to get the configuration values.

completed - Whether the configuration is complete after this setting and therefore the values should be verified.

Throws:

ConfigurationException - If there are problems with the configuration, for instance the configuration does not provide required values, a ConfigurationException may be thrown.

verifyConfigurationValues

protected void verifyConfigurationValues()
                                  throws ConfigurationException

This method verifies the configuration values that have been set yet. If a configuration value is missing or inappropriate, a ConfigurationException will be thrown.

Throws:

ConfigurationException - If there are problems with the configuration, for instance the configuration does not provide required values, a ConfigurationException may be thrown.

setConfiguration

public void setConfiguration(Configuration conf,
                             java.lang.String id)
                      throws ConfigurationException

Description copied from interface: EventSource

Sets the (additional) configuration of this event source and its ID. The configuration is additional with respect to the configuration provided by the plugin load mechanism, if the event source is loaded as plugin.
It is ensured that this method will be called before Runnable.run().

Specified by:

setConfiguration in interface EventSource<FileEvent>

Overrides:

setConfiguration in class AbstractEventSource<FileEvent>

Parameters:

conf - The configuration of this event source. This adheres (and overwrites) the configuration provided by the plugin loading, if this event source has been loaded as plugin. Whether this is allowed to be null depends on the implementation of the event source.

id - The ID of this event source. This must not be null nor the empty string.

Throws:

ConfigurationException - If there are problems with the designated configuration (configuration is null although this is not allowed, a required configuration value is missing, ...), a ConfigurationException will be thrown.

getPollTime

public long getPollTime()

Description copied from interface: PollingSource

Gets the time in milliseconds this event source polls, more precisely, the time span between two polls. If this is 0 or negative, no polling will apply. However, PollingSource.init() and PollingSource.terminate() will be called.

Specified by:

getPollTime in interface PollingSource<FileEvent>

Returns:

The time in milliseconds this event source polls (> 0).

getStartTime

public long getStartTime()

Description copied from interface: PollingSource

Gets the absolute time in milliseconds since midnight, January 1, 1970 UTC when this polling source should start polling. This is used for calculating the first poll time by adding the time span defined in PollingSource.getPollTime().

Specified by:

getStartTime in interface PollingSource<FileEvent>

Returns:

The absolute time in milliseconds since midnight, January 1, 1970 UTC when this polling source should start polling.

init

public void init()

Description copied from interface: PollingSource

Initialises this polling source. This is called once before polling is started the first time.

Specified by:

init in interface PollingSource<FileEvent>

checkForAndHandleEvent

public void checkForAndHandleEvent()

Description copied from class: AbstractEventSource

Checks for an event and handles it (usually by using AbstractEventSource.forwardEvent(Event, boolean, boolean)).

Specified by:

checkForAndHandleEvent in class AbstractEventSource<FileEvent>

terminate

public void terminate()

Description copied from interface: PollingSource

Terminates this polling source. This is called once after polling has terminated and this source is removed.
Note that this may be called any time, even when creating or handling an event. So take care to synchronise the implementation appropriately!

Specified by:

terminate in interface PollingSource<FileEvent>

createFileEvent

protected FileEvent createFileEvent(java.nio.file.Path path)
                             throws java.io.IOException

Creates a FileEvent for the designated path.

Parameters:

path - The path for which to create a FileEvent.

Returns:

The FileEvent created for the designated path.

Throws:

java.io.IOException - If retrieving the basic file attributes of the designated path fails, an IOException will be thrown.

createFileEvent

@Deprecated
protected FileEvent createFileEvent(java.io.File file)
                                         throws java.io.IOException

Deprecated. Use createFileEvent(Path) instead.

Creates a FileEvent for the designated file.

Parameters:

file - The file for which to create a FileEvent.

Returns:

The FileEvent created for the designated file.

Throws:

java.io.IOException - Retrieving the URL of the file may throw an IOException.

createLockFileEvent

protected LockFileEvent createLockFileEvent(java.nio.file.Path path,
                                            java.nio.file.Path lockPath)
                                     throws java.io.IOException

Creates a FileEvent for the designated file and its lock file.

Parameters:

path - The path for which to create a LockFileEvent.

lockPath - The path for the corresponding lock file.

Returns:

The FileEvent created for the designated path and lock file.

Throws:

java.io.IOException - If retrieving the basic file attributes of the designated path fails, an IOException will be thrown.

createLockFileEvent

@Deprecated
protected FileEvent createLockFileEvent(java.io.File file,
                                                    java.io.File lockFile)
                                             throws java.io.IOException

Deprecated. Use createLockFileEvent(Path, Path) instead.

Creates a FileEvent for the designated file and its lock file.

Parameters:

file - The file for which to create a FileEvent.

lockFile - The corresponding lock file.

Returns:

The FileEvent created for the designated file.

Throws:

java.io.IOException - Retrieving the URL of the file may throw an IOException.

nextHandler

protected boolean nextHandler(FileEvent event,
                              boolean consumed,
                              boolean concurrent)

Description copied from class: AbstractEventSource

This method is called right before an event is offered to the next handler. In case of concurrent handling, this method will only be called once for all concurrent handling but this will be indicated by the corresponding parameter.

Specified by:

nextHandler in class AbstractEventSource<FileEvent>

Parameters:

event - The event which is about to be handled by the next registered handler.

consumed - Whether the event has been consumed yet.

concurrent - Whether the next event handling is concurrent and thus the event will be offered to several event handler concurrently.

Returns:

Whether the event handling may continue. In case of serious problems preventing further event handling, return false here.