de.umass.lastfm.cache
Class FileSystemCache

java.lang.Object
  de.umass.lastfm.cache.Cache
      de.umass.lastfm.cache.FileSystemCache

All Implemented Interfaces:

ScrobbleCache

public class FileSystemCache
extends Cache
implements ScrobbleCache

Standard Cache implementation which is used by default by the Caller class. This implementation caches all responses in the file system. In addition to the raw responses it stores a .meta file which contains the expiration date for the specified request.

Author:

Janni Kovacs

Constructor Summary

FileSystemCache()

FileSystemCache(File cacheDir)

Method Summary

void	cacheScrobble(Collection<SubmissionData> submissions) Caches a collection of SubmissionData.
void	cacheScrobble(SubmissionData... submissions) Caches one or more SubmissionData.
void	cacheScrobbles(Collection<ScrobbleData> scrobbles)
void	cacheScrobbles(ScrobbleData... scrobbles)
void	clear() Clears the cache by effectively removing all cached data.
void	clearScrobbleCache() Clears all cached scrobbles from this cache.
boolean	contains(String cacheEntryName) Checks if the cache contains an entry with the given name.
boolean	isEmpty() Checks if the cache contains any scrobbles.
boolean	isExpired(String cacheEntryName) Checks if the specified entry is expired.
InputStream	load(String cacheEntryName) Loads the specified entry from the cache and returns an InputStream to be read from.
void	remove(String cacheEntryName) Removes the specified entry from the cache if available.
void	scrobble(Scrobbler scrobbler) Tries to scrobble all cached scrobbles.
List<ScrobbleResult>	scrobble(Session session)
void	store(String cacheEntryName, InputStream inputStream, long expirationDate) Stores a request in the cache.

Methods inherited from class de.umass.lastfm.cache.Cache

createCacheEntryName, findExpirationDate, getExpirationPolicy, setExpirationPolicy, setHashCacheEntryNames

Methods inherited from class java.lang.Object

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

Constructor Detail

FileSystemCache

public FileSystemCache()

FileSystemCache

public FileSystemCache(File cacheDir)

Method Detail

contains

public boolean contains(String cacheEntryName)

Description copied from class: Cache

Checks if the cache contains an entry with the given name.

Specified by:

contains in class Cache

Parameters:

cacheEntryName - An entry name

Returns:

true if the cache contains this entry

remove

public void remove(String cacheEntryName)

Description copied from class: Cache

Removes the specified entry from the cache if available. Does nothing if no such entry is available.

Specified by:

remove in class Cache

Parameters:

cacheEntryName - An entry name

isExpired

public boolean isExpired(String cacheEntryName)

Description copied from class: Cache

Checks if the specified entry is expired.

Specified by:

isExpired in class Cache

Parameters:

cacheEntryName - An entry name

Returns:

true if the entry is expired

clear

public void clear()

Description copied from class: Cache

Clears the cache by effectively removing all cached data.

Specified by:

clear in class Cache

load

public InputStream load(String cacheEntryName)

Description copied from class: Cache

Loads the specified entry from the cache and returns an InputStream to be read from. Returns null if the cache does not contain the specified cacheEntryName.

Specified by:

load in class Cache

Parameters:

cacheEntryName - An entry name

Returns:

an InputStream or null

store

public void store(String cacheEntryName,
                  InputStream inputStream,
                  long expirationDate)

Description copied from class: Cache

Stores a request in the cache.

Specified by:

store in class Cache

Parameters:

cacheEntryName - The entry name to be stored to

inputStream - An InputStream containing the data to be cached

expirationDate - The date of expiration represented in milliseconds since 1.1.1970

cacheScrobble

public void cacheScrobble(Collection<SubmissionData> submissions)

Description copied from interface: ScrobbleCache

Caches a collection of SubmissionData.

Specified by:

cacheScrobble in interface ScrobbleCache

Parameters:

submissions - The submissions

cacheScrobble

public void cacheScrobble(SubmissionData... submissions)

Description copied from interface: ScrobbleCache

Caches one or more SubmissionData.

Specified by:

cacheScrobble in interface ScrobbleCache

Parameters:

submissions - The submissions

isEmpty

public boolean isEmpty()

Description copied from interface: ScrobbleCache

Checks if the cache contains any scrobbles.

Specified by:

isEmpty in interface ScrobbleCache

Returns:

true if this cache is empty

scrobble

public void scrobble(Scrobbler scrobbler)
              throws IOException

Description copied from interface: ScrobbleCache

Tries to scrobble all cached scrobbles. If it succeeds the cache will be empty afterwards. If this method fails an IOException is thrown and no entries are removed from the cache.

Specified by:

scrobble in interface ScrobbleCache

Parameters:

scrobbler - A Scrobbler instance

Throws:

IOException - on I/O errors

clearScrobbleCache

public void clearScrobbleCache()

Description copied from interface: ScrobbleCache

Clears all cached scrobbles from this cache.

Specified by:

clearScrobbleCache in interface ScrobbleCache

cacheScrobbles

public void cacheScrobbles(Collection<ScrobbleData> scrobbles)

cacheScrobbles

public void cacheScrobbles(ScrobbleData... scrobbles)

scrobble

public List<ScrobbleResult> scrobble(Session session)
                              throws IOException

Throws:

IOException