uk.co.weft.alert
Class FileWatcher

java.lang.Object
  uk.co.weft.alert.Watcher
      uk.co.weft.alert.AbstractFileWatcher
          uk.co.weft.alert.FileWatcher

All Implemented Interfaces:

java.lang.Runnable

public class FileWatcher

extends AbstractFileWatcher

An agent which watches for changes to a file and sends alerts based on those events. This class is primarily an example of how to use Watcher, although it is of course useful in its own right.

This agent knows about the following tokens which can be uses as either command-line parameters or configuration file properties:

f, watchedfile

String: The name of the file to watch (no wildcards)

These are in addition to the tokens known by Watcher.

In the alert context, this agent sets the following tokens which can be used to substitute into the template:

changedat

String: the time the file being watched last changed

watchedfile

String: The name of the file being watched.

If you use it you will typically set up a config file such as this:

debug: true
period: 10
mail_from_address: watcher@your.domain
mail_to_address: you@your.domain
subject: Watched file has changed
template: /home/you/tmp/watcher/watcher.template
watchedfile: /home/you/tmp/foo
    

However you could achieve exactly the same result by using java uk.co.weft.alert.FileWatcher -a watcher@your.domain -f ~/tmp/foo -i 10 -r you@your.domain -s "Watched file has changed" -t ~/tmp/watcher/watcher.template

Since:

Jacquard 1.9 This revision: $Author: simon $

Version:

$Revision: 1.10.4.1 $

Author:

Simon Brooke

Nested Class Summary

Nested classes inherited from class uk.co.weft.alert.AbstractFileWatcher

AbstractFileWatcher.FileValues

Field Summary

static java.lang.String	FILETOKEN
protected long	lastModified when it last changed
protected long	lastSize how big it was
static java.lang.String	OBSERVEDVALUESTOKEN
protected java.lang.String	path the path to the file I watch
protected java.io.File	watched the file I watch
static java.lang.String	WHENCHANGEDTOKEN

Fields inherited from class uk.co.weft.alert.Watcher

alerter, alerts, configuration, debug, DEBUGTOKEN, ERRORTOKEN, INTERVALTOKEN, name, NAMETOKEN, recipient, resourceBundleName, sender, subject, SUBJECTTOKEN, template, TEMPLATETOKEN, thread, tooManyErrors, TOOMANYERRORS, whinges, winks

Constructor Summary

FileWatcher()

Method Summary

protected java.util.Vector	check() perform a check to see whether the event I am watching for has occurred.
void	init(java.util.Map config) initialise me with this configuration
static void	main(java.lang.String[] args)

Methods inherited from class uk.co.weft.alert.AbstractFileWatcher

mark, maybeEscapePath

Methods inherited from class uk.co.weft.alert.Watcher

coerceToUrl, getAlerts, getArgs, getName, getNextCheck, getResource, getResourceString, getState, getStringWithDefault, getWhinges, grs, grs, maybeCheck, reset, resetWhinges, run, sendAlert, start, stop, usage, whinge

Methods inherited from class java.lang.Object

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

Field Detail

FILETOKEN

public static final java.lang.String FILETOKEN

See Also:

Constant Field Values

WHENCHANGEDTOKEN

public static final java.lang.String WHENCHANGEDTOKEN

See Also:

Constant Field Values

OBSERVEDVALUESTOKEN

public static final java.lang.String OBSERVEDVALUESTOKEN

See Also:

Constant Field Values

path

protected java.lang.String path

the path to the file I watch

watched

protected java.io.File watched

the file I watch

lastModified

protected long lastModified

when it last changed

lastSize

protected long lastSize

how big it was

Constructor Detail

FileWatcher

public FileWatcher()

Method Detail

init

public void init(java.util.Map config)
          throws AlertingException

initialise me with this configuration

Overrides:

init in class AbstractFileWatcher

Throws:

AlertingException

check

protected java.util.Vector check()
                          throws java.lang.Exception

perform a check to see whether the event I am watching for has occurred.

Specified by:

check in class Watcher

Returns:

a vector of maps each one of which represents an alert which should be sent.

Throws:

java.lang.Exception

main

public static void main(java.lang.String[] args)
                 throws java.lang.Exception

Throws:

java.lang.Exception