org.zkoss.io
Class FileWatchdog

java.lang.Object
  java.lang.Thread
      org.zkoss.io.FileWatchdog

All Implemented Interfaces:

java.lang.Runnable

public class FileWatchdog
extends java.lang.Thread

File modification monitor thread. It monitors a gving file in a lowest priority thread. Then, if it detects any modification, invokes a giving interface. Note: Callback.onModified is at least called once.

Caller has to implement the FileWatchdog.Callback interface. Then,
new FileWatchdog(filename, 30000, callback).start();

This class is extended from Thread, so you could manipulate it as a normal thread, such as interrupt, suspend, and change priority.

The watchdog executes at the lowest priority, so it won't affect much of the system performance.

Author:

tomyeh

Nested Class Summary

static interface

FileWatchdog.Callback The interface to implement when using a FileWatchdog.

Nested classes/interfaces inherited from class java.lang.Thread

java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

FileWatchdog(java.io.File file, long delay, FileWatchdog.Callback callback)
Constructor.

FileWatchdog(java.lang.String filename, long delay, FileWatchdog.Callback callback)
Constructor.

Method Summary

void	cease() Stops the thread.
void	run()
void	start()

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Constructor Detail

FileWatchdog

public FileWatchdog(java.io.File file,
                    long delay,
                    FileWatchdog.Callback callback)

Constructor.

Parameters:

file - the file

delay - the delay in milliseconds to wait between each check

callback - the callback

FileWatchdog

public FileWatchdog(java.lang.String filename,
                    long delay,
                    FileWatchdog.Callback callback)

Constructor.

Parameters:

filename - the filename

delay - the delay in milliseconds to wait between each check

callback - the callback

Method Detail

start

public void start()

Overrides:

start in class java.lang.Thread

cease

public void cease()

Stops the thread.

run

public void run()

Specified by:

run in interface java.lang.Runnable

Overrides:

run in class java.lang.Thread