Class DefaultFileMonitor
- All Implemented Interfaces:
- AutoCloseable,- Runnable,- FileMonitor
FileMonitor implementation.
 The DefaultFileMonitor is a Thread based polling file system monitor with a 1 second delay.
Design:
There is a Map of monitors known as FileMonitorAgents. With the thread running, each FileMonitorAgent object is asked to "check" on the file it is responsible for. To do this check, the cache is cleared.
- If the file existed before the refresh and it no longer exists, a delete event is fired.
- If the file existed before the refresh and it still exists, check the last modified timestamp to see if that has changed.
- If it has, fire a change event.
With each file delete, the FileMonitorAgent of the parent is asked to re-build its list of children, so that they can be accurately checked when there are new children.
New files are detected during each "check" as each file does a check for new children. If new children are found, create events are fired recursively if recursive descent is enabled.
For performance reasons, added a delay that increases as the number of files monitored increases. The default is a delay of 1 second for every 1000 files processed.
Example usage:
 FileSystemManager fsManager = VFS.getManager();
 FileObject listenDir = fsManager.resolveFile("/home/username/monitored/");
 DefaultFileMonitor fm = new DefaultFileMonitor(new CustomFileListener());
 fm.setRecursive(true);
 fm.addFile(listenDir);
 fm.start();
 
 (where CustomFileListener is a class that implements the FileListener interface.)- 
Constructor SummaryConstructorsConstructorDescriptionDefaultFileMonitor(FileListener listener) Constructs a new instance with the given listener.
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Method SummaryModifier and TypeMethodDescriptionvoidaddFile(FileObject file) Adds a file to be monitored.voidclose()intGets the number of files to check per run.longgetDelay()Deprecated.Gets the delay between runs.booleanTests the recursive setting when adding files for monitoring.protected voidqueueAddFile(FileObject file) Queues a file for addition to be monitored.protected voidqueueRemoveFile(FileObject file) Queues a file for removal from being monitored.voidremoveFile(FileObject file) Removes a file from being monitored.voidrun()Asks the agent for each file being monitored to check its file for changes.voidsetChecksPerRun(int checksPerRun) Sets the number of files to check per run.voidsetDelay(long delay) Deprecated.UsesetDelay(Duration).voidSets the delay between runs.voidsetRecursive(boolean newRecursive) Sets the recursive setting when adding files for monitoring.voidstart()Starts monitoring the files that have been added.voidstop()Stops monitoring the files that have been added.
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Constructor Details- 
DefaultFileMonitorConstructs a new instance with the given listener.- Parameters:
- listener- the listener.
 
 
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Method Details- 
addFileAdds a file to be monitored.- Specified by:
- addFilein interface- FileMonitor
- Parameters:
- file- The FileObject to monitor.
 
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close- Specified by:
- closein interface- AutoCloseable
 
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getChecksPerRunGets the number of files to check per run.- Returns:
- The number of files to check per iteration.
 
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getDelayDeprecated.UsegetDelayDuration().Gets the delay between runs.- Returns:
- The delay period in milliseconds.
 
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getDelayDurationGets the delay between runs.- Returns:
- The delay period.
 
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isRecursiveTests the recursive setting when adding files for monitoring.- Returns:
- true if monitoring is enabled for children.
 
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queueAddFileQueues a file for addition to be monitored.- Parameters:
- file- The FileObject to add.
 
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queueRemoveFileQueues a file for removal from being monitored.- Parameters:
- file- The FileObject to be removed from being monitored.
 
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removeFileRemoves a file from being monitored.- Specified by:
- removeFilein interface- FileMonitor
- Parameters:
- file- The FileObject to remove from monitoring.
 
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runAsks the agent for each file being monitored to check its file for changes.
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setChecksPerRunSets the number of files to check per run. An additional delay will be added if there are more files to check.- Parameters:
- checksPerRun- a value less than 1 will disable this feature
 
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setDelaySets the delay between runs.- Parameters:
- delay- The delay period.
- Since:
- 2.10.0
 
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setDelayDeprecated.UsesetDelay(Duration).Sets the delay between runs.- Parameters:
- delay- The delay period in milliseconds.
 
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setRecursiveSets the recursive setting when adding files for monitoring.- Parameters:
- newRecursive- true if monitoring should be enabled for children.
 
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startStarts monitoring the files that have been added.
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stopStops monitoring the files that have been added.
 
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getDelayDuration().