net.sourceforge.rssowl.util.archive
Class FeedCacheManager

java.lang.Object
  net.sourceforge.rssowl.util.archive.FeedCacheManager

public class FeedCacheManager

extends Object

Cache manager for RSSOwl. Any loaded newsfeed is stored in the cache folder and indexed in the newsFeedCache Hashtable. That index is serialized into a file and loaded on startup of RSSOwl. Two Hashtables manage the caching. The live cache contains Channel objects withe the URL as key, whereas the local cache contains File objects which point to the cached file where the newsfeed is stored.

Version:

1.1.3

Author:

Benjamin Pasero

Field Summary

private static String	CACHE_INDEX File to serialize the cache index into
private static long	FILE_TIME_TO_LIVE Max time to live for unmodified cache files (2 days)
private Hashtable	newsFeedLiveCache Live cache will store RSSChannels
private Hashtable	newsFeedLocalCache Local cache will store File reference to cached files

Constructor Summary

FeedCacheManager()
Instantiate a new FeedCacheManager

Method Summary

void	cacheNewsfeed(String url, Channel rssChannel) Cache a newsfeed
private void	cleanUpCache() Remove those files from the archive which were not modified over a long period
private void	deleteCache() Delete the cache as it is no longer used in RSSOwl
private void	deserializeCache() Load the local cache index from local file
Channel	getCachedNewsfeed(String url) Get a cached newsfeed from the feed cache
boolean	isNewsfeedCached(String url) Check if a newsfeed is cached by a unique identifier in either the live cache (memory) or local (file)
boolean	isNewsfeedCached(String url, boolean allowLocalCache) Check if a newsfeed is cached by a unique identifier in either the live cache (memory) and local (file) is allowLocalCache is set to TRUE
private File	saveDocument(org.jdom.Document document) Save the newsfeed's XML document into a unique file in the cache dir and return the reference to the new file
private void	serializeCache() Save the chache index into local file
void	shutdown() Serialize the index on application exit and cleanup old chache items
void	unCacheNewsfeed(String url, boolean deleteLocalCache) Remove a newsfeed from the cache and delete its cache file

Methods inherited from class java.lang.Object

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

Field Detail

CACHE_INDEX

private static final String CACHE_INDEX

File to serialize the cache index into

See Also:

Constant Field Values

FILE_TIME_TO_LIVE

private static final long FILE_TIME_TO_LIVE

Max time to live for unmodified cache files (2 days)

See Also:

Constant Field Values

newsFeedLiveCache

private Hashtable newsFeedLiveCache

Live cache will store RSSChannels

newsFeedLocalCache

private Hashtable newsFeedLocalCache

Local cache will store File reference to cached files

Constructor Detail

FeedCacheManager

public FeedCacheManager()

Instantiate a new FeedCacheManager

Method Detail

cacheNewsfeed

public void cacheNewsfeed(String url,
                          Channel rssChannel)

Cache a newsfeed

Parameters:

url - Unique identifier

rssChannel - The newsfeed to cache

getCachedNewsfeed

public Channel getCachedNewsfeed(String url)

Get a cached newsfeed from the feed cache

Parameters:

url - Unique identifier

Returns:

Channel The cached newsfeed

isNewsfeedCached

public boolean isNewsfeedCached(String url)

Check if a newsfeed is cached by a unique identifier in either the live cache (memory) or local (file)

Parameters:

url - Unique identifier

Returns:

boolean TRUE if newsfeed is cached

isNewsfeedCached

public boolean isNewsfeedCached(String url,
                                boolean allowLocalCache)

Check if a newsfeed is cached by a unique identifier in either the live cache (memory) and local (file) is allowLocalCache is set to TRUE

Parameters:

url - Unique identifier

allowLocalCache - If TRUE also look in local file cache

Returns:

boolean TRUE if newsfeed is cached

shutdown

public void shutdown()

Serialize the index on application exit and cleanup old chache items

unCacheNewsfeed

public void unCacheNewsfeed(String url,
                            boolean deleteLocalCache)

Remove a newsfeed from the cache and delete its cache file

Parameters:

url - Unique identifier

deleteLocalCache - If TRUE, also uncache local file

cleanUpCache

private void cleanUpCache()

Remove those files from the archive which were not modified over a long period

deleteCache

private void deleteCache()

Delete the cache as it is no longer used in RSSOwl

deserializeCache

private void deserializeCache()

Load the local cache index from local file

saveDocument

private File saveDocument(org.jdom.Document document)
                   throws IOException

Save the newsfeed's XML document into a unique file in the cache dir and return the reference to the new file

Parameters:

document - The newsfeed's document to save

Returns:

File The new cache file that was created

Throws:

IOException - If an error occurs

serializeCache

private void serializeCache()

Save the chache index into local file