|
What this is
Other links
The source code/* * Copyright (C) The Apache Software Foundation. All rights reserved. * * This software is published under the terms of the Apache Software License * version 1.1, a copy of which has been included with this distribution in * the LICENSE file. */ // Contributors: Mathias Bogaert package org.apache.log4j.helpers; import java.io.File; import org.apache.log4j.helpers.LogLog; /** Check every now and then that a certain file has not changed. If it has, then call the {@link #doOnChange} method. @author Ceki Gülcü @since version 0.9.1 */ public abstract class FileWatchdog extends Thread { /** The default delay between every file modification check, set to 60 seconds. */ static final public long DEFAULT_DELAY = 60000; /** The name of the file to observe for changes. */ protected String filename; /** The delay to observe between every check. By default set {@link #DEFAULT_DELAY}. */ protected long delay = DEFAULT_DELAY; File file; long lastModif = 0; boolean warnedAlready = false; boolean interrupted = false; protected FileWatchdog(String filename) { this.filename = filename; file = new File(filename); setDaemon(true); checkAndConfigure(); } /** Set the delay to observe between each check of the file changes. */ public void setDelay(long delay) { this.delay = delay; } abstract protected void doOnChange(); protected void checkAndConfigure() { boolean fileExists; try { fileExists = file.exists(); } catch(SecurityException e) { LogLog.warn("Was not allowed to read check file existance, file:["+ filename+"]."); interrupted = true; // there is no point in continuing return; } if(fileExists) { long l = file.lastModified(); // this can also throw a SecurityException if(l > lastModif) { // however, if we reached this point this lastModif = l; // is very unlikely. doOnChange(); warnedAlready = false; } } else { if(!warnedAlready) { LogLog.debug("["+filename+"] does not exist."); warnedAlready = true; } } } public void run() { while(!interrupted) { try { Thread.currentThread().sleep(delay); } catch(InterruptedException e) { // no interruption expected } checkAndConfigure(); } } } |
... this post is sponsored by my books ... | |
#1 New Release! |
FP Best Seller |
Copyright 1998-2024 Alvin Alexander, alvinalexander.com
All Rights Reserved.
A percentage of advertising revenue from
pages under the /java/jwarehouse
URI on this website is
paid back to open source projects.