org.apache.commons.cache
Class BaseCache

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

All Implemented Interfaces:

Serializable, Cache

Direct Known Subclasses:

NoOpCache, SimpleCache

public abstract class BaseCache
extends Object
implements Cache

An abstract base Cache implementation, managing the registration of listeners and the broadcast of events.

Version:

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

Author:

Rodney Waldhoff

See Also:

Serialized Form

Field Summary

protected ArrayList	_retrievalListeners My list of RetrievalListeners.
protected ArrayList	_storageListeners My list of StorageListeners.

Constructor Summary

BaseCache()

Method Summary

protected void	broadcastCleared() Broadcast a StorageListener.cleared() event to my set of StorageListeners.
protected void	broadcastCleared(Serializable key) Broadcast a StorageListener.cleared(java.io.Serializable) event to my set of StorageListeners.
protected void	broadcastNotRetrieved(Serializable key) Broadcast a RetrievalListener.notRetrieved(java.io.Serializable) event to my set of RetrievalListeners.
protected void	broadcastNotStored(Serializable key, Serializable val, Long expiresAt, Long cost, Serializable group) Broadcast a StorageListener.notStored(java.io.Serializable,java.io.Serializable,java.lang.Long,java.lang.Long,java.io.Serializable) event to my set of StorageListeners.
protected void	broadcastRetrieved(Serializable key) Broadcast a RetrievalListener.retrieved(java.io.Serializable) event to my set of RetrievalListeners.
protected void	broadcastRetrieveRequested(Serializable key) Broadcast a RetrievalListener.retrieveRequested(java.io.Serializable) event to my set of RetrievalListeners.
protected void	broadcastStored(Serializable key, Serializable val, Long expiresAt, Long cost, Serializable group) Broadcast a StorageListener.stored(java.io.Serializable,java.io.Serializable,java.lang.Long,java.lang.Long,java.io.Serializable) event to my set of StorageListeners.
protected void	broadcastStoreRequested(Serializable key, Serializable val, Long expiresAt, Long cost, Serializable group) Broadcast a StorageListener.storeRequested(java.io.Serializable,java.io.Serializable,java.lang.Long,java.lang.Long,java.io.Serializable) event to my set of StorageListeners.
abstract void	clear() Remove all values previously stored.
abstract void	clear(Serializable key) Remove any value previously stored under the given key.
void	clearGroup(Serializable group) Remove any value previously stored under the given group.
abstract boolean	contains(Serializable key) Returns true if I have a value associated with the given key, false otherwise.
abstract Serializable[]	getKeysForGroup(Serializable group)
long	getStat(CacheStat stat)
void	registerRetrievalListener(RetrievalListener obs) Add the given RetrievalListener to my set of RetrievalListeners.
void	registerStorageListener(StorageListener obs) Add the given StorageListener to my set of StorageListeners.
abstract Serializable	retrieve(Serializable key) Obtain the value previously stored under the given key.
boolean	store(Serializable key, Serializable val, Long expiry, Long cost) Store the specified val under the specified key.
abstract boolean	store(Serializable key, Serializable val, Long expiry, Long cost, Serializable group) Store the specified val under the specified key and the specified group.
void	unregisterRetrievalListener(RetrievalListener obs) Remove the given RetrievalListener from my set of RetrievalListeners.
void	unregisterRetrievalListeners() Clear my set of RetrievalListeners.
void	unregisterStorageListener(StorageListener obs) Remove the given StorageListener from my set of StorageListeners.
void	unregisterStorageListeners() Clear my set of StorageListeners.

Methods inherited from class java.lang.Object

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

Field Detail

_storageListeners

protected ArrayList _storageListeners

My list of StorageListeners.

_retrievalListeners

protected ArrayList _retrievalListeners

My list of RetrievalListeners.

Constructor Detail

BaseCache

public BaseCache()

Method Detail

store

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

Description copied from interface: Cache

Store the specified val under the specified key and the specified group.

Specified by:

store in interface Cache

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 abstract Serializable retrieve(Serializable key)

Description copied from interface: Cache

Obtain the value previously stored under the given key.

Specified by:

retrieve in interface Cache

Parameters:

key - the key which MUST NOT be null.

Returns:

the previously stored value, or null.

getKeysForGroup

public abstract Serializable[] getKeysForGroup(Serializable group)

Specified by:

getKeysForGroup in interface Cache

contains

public abstract boolean contains(Serializable key)

Description copied from interface: Cache

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

Specified by:

contains in interface Cache

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 abstract void clear(Serializable key)

Description copied from interface: Cache

Remove any value previously stored under the given key.

Specified by:

clear in interface Cache

Parameters:

key - the key which MUST NOT be null.

clear

public abstract void clear()

Description copied from interface: Cache

Remove all values previously stored.

Specified by:

clear in interface Cache

getStat

public long getStat(CacheStat stat)
             throws UnsupportedOperationException

Specified by:

getStat in interface Cache

Throws:

UnsupportedOperationException

clearGroup

public void clearGroup(Serializable group)

Description copied from interface: Cache

Remove any value previously stored under the given group.

Specified by:

clearGroup in interface Cache

Parameters:

group - the group which MUST NOT be null.

store

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

Description copied from interface: Cache

Store the specified val under the specified key.

Specified by:

store in interface Cache

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.

Returns:

true if the val was stored, false otherwise.

registerStorageListener

public void registerStorageListener(StorageListener obs)

Add the given StorageListener to my set of StorageListeners.

Specified by:

registerStorageListener in interface Cache

unregisterStorageListener

public void unregisterStorageListener(StorageListener obs)

Remove the given StorageListener from my set of StorageListeners.

Specified by:

unregisterStorageListener in interface Cache

unregisterStorageListeners

public void unregisterStorageListeners()

Clear my set of StorageListeners.

Specified by:

unregisterStorageListeners in interface Cache

registerRetrievalListener

public void registerRetrievalListener(RetrievalListener obs)

Add the given RetrievalListener to my set of RetrievalListeners.

Specified by:

registerRetrievalListener in interface Cache

unregisterRetrievalListener

public void unregisterRetrievalListener(RetrievalListener obs)

Remove the given RetrievalListener from my set of RetrievalListeners.

Specified by:

unregisterRetrievalListener in interface Cache

unregisterRetrievalListeners

public void unregisterRetrievalListeners()

Clear my set of RetrievalListeners.

Specified by:

unregisterRetrievalListeners in interface Cache

broadcastStoreRequested

protected void broadcastStoreRequested(Serializable key,
                                       Serializable val,
                                       Long expiresAt,
                                       Long cost,
                                       Serializable group)

Broadcast a StorageListener.storeRequested(java.io.Serializable,java.io.Serializable,java.lang.Long,java.lang.Long,java.io.Serializable) event to my set of StorageListeners.

Parameters:

key - the cache key

val - the cache value

expiresAt - the expiration timestamp, or null

cost - the cost of the object, or null

broadcastStored

protected void broadcastStored(Serializable key,
                               Serializable val,
                               Long expiresAt,
                               Long cost,
                               Serializable group)

Broadcast a StorageListener.stored(java.io.Serializable,java.io.Serializable,java.lang.Long,java.lang.Long,java.io.Serializable) event to my set of StorageListeners.

Parameters:

key - the cache key

val - the cache value

expiresAt - the expiration timestamp, or null

cost - the cost of the object, or null

broadcastNotStored

protected void broadcastNotStored(Serializable key,
                                  Serializable val,
                                  Long expiresAt,
                                  Long cost,
                                  Serializable group)

Broadcast a StorageListener.notStored(java.io.Serializable,java.io.Serializable,java.lang.Long,java.lang.Long,java.io.Serializable) event to my set of StorageListeners.

Parameters:

key - the cache key

val - the cache value

expiresAt - the expiration timestamp, or null

cost - the cost of the object, or null

broadcastCleared

protected void broadcastCleared(Serializable key)

Broadcast a StorageListener.cleared(java.io.Serializable) event to my set of StorageListeners.

Parameters:

key - the cache key

broadcastCleared

protected void broadcastCleared()

Broadcast a StorageListener.cleared() event to my set of StorageListeners.

broadcastRetrieveRequested

protected void broadcastRetrieveRequested(Serializable key)

Broadcast a RetrievalListener.retrieveRequested(java.io.Serializable) event to my set of RetrievalListeners.

Parameters:

key - the cache key

broadcastRetrieved

protected void broadcastRetrieved(Serializable key)

Broadcast a RetrievalListener.retrieved(java.io.Serializable) event to my set of RetrievalListeners.

Parameters:

key - the cache key

broadcastNotRetrieved

protected void broadcastNotRetrieved(Serializable key)

Broadcast a RetrievalListener.notRetrieved(java.io.Serializable) event to my set of RetrievalListeners.

Parameters:

key - the cache key