org.sape.carbon.core.config.node.file
Class ConfigurationFileMonitor

java.lang.Object
  |
  +--org.sape.carbon.core.config.node.file.ConfigurationFileMonitor

All Implemented Interfaces:

ConfigurationEventListener, EventListener

public class ConfigurationFileMonitor

extends Object

implements ConfigurationEventListener

This class manages a thread that monitors files for changes at a periodic interval. When a file is changed or removed, it is detected and the corresponding configuration node is refreshed.

Copyright 2003 Sapient

Since:

carbon 2.2

Version:

$Revision: 1.1 $($Author: dvoet $ / $Date: 2003/12/18 18:42:14 $)

Author:

Douglas Voet, Dec 11, 2003

Nested Class Summary

private class	ConfigurationFileMonitor.Monitor Runnable class that implements the monitor thread's functionality.
private static class	ConfigurationFileMonitor.NodeInfo Helper class that maintains info about a node and its file.

Field Summary

private org.apache.commons.logging.Log	log
private Map	monitoredFiles synchronized map of files that are being monitored key = (String) node absolute name value = NodeInfo object
private Thread	monitorThread Thread monitoring files
private long	pollInterval The interval at which the files are polled to see if they have changed
private String	threadName Name of the trhead

Constructor Summary

ConfigurationFileMonitor(Node entryPoint, long pollInterval)
Constructs a new ConfigurationFileMonitor

Method Summary

private void	addFileToMonitor(Node fileNode) Helper method to add a file to the monitor
void	childAdded(Node parent, Node child) updates the last modifed timestamp associate with parent and adds child to the monitored files map
void	childLoaded(Node parent, Node child) adds child to the monitored files map
void	interrupt() Interrupts the monitor thread.
private void	monitorThreadEnded()
void	nodeModified(Node node) Updates the last modifed timestamp associated with the node
void	nodeRemoved(String removedNodeName) removes the node from the monitored files map
void	start() Starts the monitor thread.

Methods inherited from class java.lang.Object

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

Field Detail

log

private org.apache.commons.logging.Log log

monitoredFiles

private Map monitoredFiles

synchronized map of files that are being monitored key = (String) node absolute name value = NodeInfo object

monitorThread

private Thread monitorThread

Thread monitoring files

threadName

private String threadName

Name of the trhead

pollInterval

private long pollInterval

The interval at which the files are polled to see if they have changed

Constructor Detail

ConfigurationFileMonitor

public ConfigurationFileMonitor(Node entryPoint,
                                long pollInterval)

Constructs a new ConfigurationFileMonitor

Parameters:

entryPoint - the node that is the root of configuration hierachy that is to be monitored. This does not need to be the root of the entire configuration hierachy.

pollInterval - the interval at which the files are polled to see if they have changed

Method Detail

nodeModified

public void nodeModified(Node node)

Updates the last modifed timestamp associated with the node

Specified by:

nodeModified in interface ConfigurationEventListener

Parameters:

node - the node that has been modified

childAdded

public void childAdded(Node parent,
                       Node child)

updates the last modifed timestamp associate with parent and adds child to the monitored files map

Specified by:

childAdded in interface ConfigurationEventListener

Parameters:

parent - the node the child was added to

child - the child that was added

childLoaded

public void childLoaded(Node parent,
                        Node child)

adds child to the monitored files map

Specified by:

childLoaded in interface ConfigurationEventListener

Parameters:

parent - the node that loaded the child

child - the child that was loaded

nodeRemoved

public void nodeRemoved(String removedNodeName)

removes the node from the monitored files map

Specified by:

nodeRemoved in interface ConfigurationEventListener

Parameters:

removedNodeName - the absolute name of the removed node

interrupt

public void interrupt()

Interrupts the monitor thread. The thread can be restarted by calling the start method.

start

public void start()

Starts the monitor thread.

monitorThreadEnded

private void monitorThreadEnded()

addFileToMonitor

private void addFileToMonitor(Node fileNode)

Helper method to add a file to the monitor

Parameters:

fileNode -