org.apache.commons.cache
Class NoOpCache

java.lang.Object
  org.apache.commons.cache.BaseCache
      org.apache.commons.cache.NoOpCache

All Implemented Interfaces:

Serializable, Cache

public class NoOpCache
extends BaseCache
implements Cache

A Cache that doesn't.

Version:

$Id: NoOpCache.java 155435 2005-02-26 13:17:27Z dirkv $

Author:

Rodney Waldhoff

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.commons.cache.BaseCache

_retrievalListeners, _storageListeners

Constructor Summary

NoOpCache()

Method Summary

void	clear() No-op.
void	clear(Serializable key) No-op.
void	clearGroup(Serializable group) No-op.
boolean	contains(Serializable key) Returns false
Serializable[]	getKeysForGroup(Serializable group) Returns an empty array.
long	getStat(CacheStat stat) Throws UnsupportedOperationException
Serializable	retrieve(Serializable key) Returns null.
boolean	store(Serializable key, Serializable val, Long expiry, Long cost, Serializable group) Returns false.

Methods inherited from class org.apache.commons.cache.BaseCache

broadcastCleared, broadcastCleared, broadcastNotRetrieved, broadcastNotStored, broadcastRetrieved, broadcastRetrieveRequested, broadcastStored, broadcastStoreRequested, registerRetrievalListener, registerStorageListener, store, unregisterRetrievalListener, unregisterRetrievalListeners, unregisterStorageListener, unregisterStorageListeners

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.cache.Cache

registerRetrievalListener, registerStorageListener, store, unregisterRetrievalListener, unregisterRetrievalListeners, unregisterStorageListener, unregisterStorageListeners

Constructor Detail

NoOpCache

public NoOpCache()

Method Detail

store

public boolean store(Serializable key,
                     Serializable val,
                     Long expiry,
                     Long cost,
                     Serializable group)

Returns false.

Specified by:

store in interface Cache

Specified by:

store in class BaseCache

Parameters:

key - the key used to later obtain the val from me, which MUST NOT be null.

val - the val to store, which MUST NOT be null.

expiry - the timestamp at which the given val becomes stale, or null.

cost - the implemenation dependent cost of generating the val, or null.

group - a meta-key which can be used to clear the object later

Returns:

true if the val was stored, false otherwise.

retrieve

public Serializable retrieve(Serializable key)

Returns null.

Specified by:

retrieve in interface Cache

Specified by:

retrieve in class BaseCache

Parameters:

key - the key which MUST NOT be null.

Returns:

the previously stored value, or null.

getKeysForGroup

public Serializable[] getKeysForGroup(Serializable group)

Returns an empty array.

Specified by:

getKeysForGroup in interface Cache

Specified by:

getKeysForGroup in class BaseCache

contains

public boolean contains(Serializable key)

Returns false

Specified by:

contains in interface Cache

Specified by:

contains in class BaseCache

Parameters:

key - the key which MUST NOT be null.

Returns:

true if I have a value associated with the given key, false otherwise.

clear

public void clear(Serializable key)

No-op.

Specified by:

clear in interface Cache

Specified by:

clear in class BaseCache

Parameters:

key - the key which MUST NOT be null.

clearGroup

public void clearGroup(Serializable group)

No-op.

Specified by:

clearGroup in interface Cache

Overrides:

clearGroup in class BaseCache

Parameters:

group - the group which MUST NOT be null.

clear

public void clear()

No-op.

Specified by:

clear in interface Cache

Specified by:

clear in class BaseCache

getStat

public long getStat(CacheStat stat)
             throws UnsupportedOperationException

Throws UnsupportedOperationException

Specified by:

getStat in interface Cache

Overrides:

getStat in class BaseCache

Throws:

UnsupportedOperationException