no.feide.moria.directory
Class IndexUpdater

java.lang.Object
  java.util.TimerTask
      no.feide.moria.directory.IndexUpdater

All Implemented Interfaces:

java.lang.Runnable

public class IndexUpdater
extends java.util.TimerTask

This is the task responsible for periodically checking for a new index file, and if necessary, update the existing index.

Note that this implementation relies on no.feide.moria.directory.index.SerializableIndex as the index implementation. To change the index implementation, the method readIndex() needs to be modified.

Field Summary

private java.lang.String	filename The location of the index file.
private no.feide.moria.log.MessageLogger	log Used for logging.
private DirectoryManager	owner The instance of Directory Manager that created this task.
private long	timestamp The timestamp of the last read index file.

Constructor Summary

IndexUpdater(DirectoryManager dm, java.lang.String indexFilename)
Constructor.

Method Summary

protected DirectoryManagerIndex	readIndex() Reads an index file and create a new index object.
void	run() Performs the periodic update of the DirectoryManager's index, by calling the DirectoryManager.updateIndex(DirectoryManagerIndex) method.

Methods inherited from class java.util.TimerTask

cancel, scheduledExecutionTime

Methods inherited from class java.lang.Object

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

Field Detail

log

private final no.feide.moria.log.MessageLogger log

Used for logging.

filename

private final java.lang.String filename

The location of the index file.

timestamp

private long timestamp

The timestamp of the last read index file. Initially set to 0 (zero).

owner

private final DirectoryManager owner

The instance of Directory Manager that created this task.

Constructor Detail

IndexUpdater

public IndexUpdater(DirectoryManager dm,
                    java.lang.String indexFilename)

Constructor.

Parameters:

dm - The instance of Directory Manager that created this instance. Required since IndexUpdater uses this object directly to update its index. Cannot be null.

indexFilename - The index filename. Cannot be null.

Throws:

java.lang.NullPointerException - If dm or indexFilename is null.

Method Detail

run

public final void run()

Performs the periodic update of the DirectoryManager's index, by calling the DirectoryManager.updateIndex(DirectoryManagerIndex) method.

Specified by:

run in interface java.lang.Runnable

Specified by:

run in class java.util.TimerTask

See Also:

Runnable.run(), DirectoryManager.updateIndex(DirectoryManagerIndex)

readIndex

protected final DirectoryManagerIndex readIndex()

Reads an index file and create a new index object.

Note that this method is also called by DirectoryManager.setConfig(Properties) to force through an initial update of the index.

Returns:

The newly read index, as an object implementing the DirectoryManagerIndex interface. Will return null if this method has already been used to successfully read an index file, and the file has not been updated since (based on the file's timestamp on disk, as per the File.lastModified() method).

See Also:

File.lastModified(), DirectoryManager.setConfig(java.util.Properties)