Class Tailer

java.lang.Object

VASSAL.tools.io.Tailer

public class Tailer
extends Object

Tail a file. This class is designed to behave similarly to the UNIX command tail -f, watching the file for changes and reporting them to listeners. The tailer may be stopped when it is not needed; if it is restarted, it will remember its last position and resume reading where it left off.

Since:

3.2.0

Author:

Joel Uckelman

Field Summary

Fields

Modifier and Type	Field	Description
protected static final long	DEFAULT_POLL_INTERVAL
protected final File	file
protected final EventListenerSupport<String>	lsup
protected final long	poll_interval
protected long	position
protected boolean	tailing

Constructor Summary

Constructors

Constructor	Description
Tailer(File file)	Creates a file tailer with the default polling interval.
Tailer(File file, long poll_interval)	Creates a file tailer.
Tailer(File file, long poll_interval, EventListenerSupport<String> lsup)	Creates a file tailer.

Method Summary

Modifier and Type	Method	Description
void	addEventListener(EventListener<? super String> l)	Adds an EventListener.
List<EventListener<? super String>>	getEventListeners()	Gets the list of listerners.
File	getFile()	Gets the file being tailed.
boolean	hasEventListeners()	Checks whether there are any EventListeners.
boolean	isTailing()	Checks whether the tailer is running.
static void	main(String[] args)
void	removeEventListener(EventListener<? super String> l)	Removes an EventListener.
void	start()	Starts tailing the file.
void	stop()	Stops tailing the file.

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_POLL_INTERVAL

protected static final long DEFAULT_POLL_INTERVAL

See Also:

• Constant Field Values

file

protected final File file

poll_interval

protected final long poll_interval

position

protected long position

tailing

protected volatile boolean tailing

lsup

protected final EventListenerSupport<String> lsup

Constructor Details

Tailer

public Tailer(File file)

Creates a file tailer with the default polling interval.

Parameters:

file - the file to tail

Tailer

public Tailer(File file,
 long poll_interval)

Creates a file tailer.

Parameters:

file - the file to tail

poll_interval - the polling interval, in milliseconds

Tailer

public Tailer(File file,
 long poll_interval,
 EventListenerSupport<String> lsup)

Creates a file tailer.

Parameters:

file - the file to tail

poll_interval - the polling interval, in milliseconds

lsup - the listener support

Method Details

start

public void start()
           throws IOException

Starts tailing the file.

Throws:

IOException

stop

public void stop()

Stops tailing the file.

isTailing

public boolean isTailing()

Checks whether the tailer is running.

Returns:

true if the tailer is running

getFile

public File getFile()

Gets the file being tailed.

Returns:

the file

addEventListener

public void addEventListener(EventListener<? super String> l)

Adds an EventListener.

Parameters:

l - the listener to add

removeEventListener

public void removeEventListener(EventListener<? super String> l)

Removes an EventListener.

Parameters:

l - the listener to remove

hasEventListeners

public boolean hasEventListeners()

Checks whether there are any EventListeners.

Returns:

true if there are any listeners

getEventListeners

public List<EventListener<? super String>> getEventListeners()

Gets the list of listerners.

Returns:

the list of listeners

main

public static void main(String[] args)
                 throws IOException

Throws:

IOException