Cache (ehcache)

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net.sf.ehcache
Class Cache

java.lang.Object
  net.sf.ehcache.Cache

All Implemented Interfaces:: java.lang.Cloneable, Ehcache

public class Cache
extends java.lang.Object
implements Ehcache
extends java.lang.Object
implements Ehcache

Cache is the central class in ehcache. Caches have Elements and are managed by the CacheManager. The Cache performs logical actions. It delegates physical implementations to its Stores.

A reference to a Cache can be obtained through the CacheManager. A Cache thus obtained is guaranteed to have status Status.STATUS_ALIVE. This status is checked for any method which throws IllegalStateException and the same thrown if it is not alive. This would normally happen if a call is made after CacheManager.shutdown() is invoked.

Cache is threadsafe.

Statistics on cache usage are collected and made available through the getStatistics() methods.

Various decorators are available for Cache, such as BlockingCache, SelfPopulatingCache and the dynamic proxy ExceptionHandlingDynamicCacheProxy. See each class for details.

Version:: $Id: Cache.java 704 2008-07-13 00:17:52Z gregluck $
Author:: Greg Luck

Nested Class Summary
`(package private) class`	`Cache.KeyedFuture` Used to store a future and the key it is in respect of

Field Summary
`static java.lang.String`	`DEFAULT_CACHE_NAME` A reserved word for cache names.
`static long`	`DEFAULT_EXPIRY_THREAD_INTERVAL_SECONDS` The default interval between runs of the expiry thread.
`static java.lang.String`	`NET_SF_EHCACHE_DISABLED` System Property based method of disabling ehcache.

Constructor Summary
`Cache(java.lang.String name, int maxElementsInMemory, boolean overflowToDisk, boolean eternal, long timeToLiveSeconds, long timeToIdleSeconds)` 1.0 Constructor.
`Cache(java.lang.String name, int maxElementsInMemory, boolean overflowToDisk, boolean eternal, long timeToLiveSeconds, long timeToIdleSeconds, boolean diskPersistent, long diskExpiryThreadIntervalSeconds)` 1.1 Constructor.
`Cache(java.lang.String name, int maxElementsInMemory, MemoryStoreEvictionPolicy memoryStoreEvictionPolicy, boolean overflowToDisk, java.lang.String diskStorePath, boolean eternal, long timeToLiveSeconds, long timeToIdleSeconds, boolean diskPersistent, long diskExpiryThreadIntervalSeconds, RegisteredEventListeners registeredEventListeners)` 1.2 Constructor The `ConfigurationFactory` and clients can create these.
`Cache(java.lang.String name, int maxElementsInMemory, MemoryStoreEvictionPolicy memoryStoreEvictionPolicy, boolean overflowToDisk, java.lang.String diskStorePath, boolean eternal, long timeToLiveSeconds, long timeToIdleSeconds, boolean diskPersistent, long diskExpiryThreadIntervalSeconds, RegisteredEventListeners registeredEventListeners, BootstrapCacheLoader bootstrapCacheLoader)` 1.2.1 Constructor The `ConfigurationFactory` and clients can create these.
`Cache(java.lang.String name, int maxElementsInMemory, MemoryStoreEvictionPolicy memoryStoreEvictionPolicy, boolean overflowToDisk, java.lang.String diskStorePath, boolean eternal, long timeToLiveSeconds, long timeToIdleSeconds, boolean diskPersistent, long diskExpiryThreadIntervalSeconds, RegisteredEventListeners registeredEventListeners, BootstrapCacheLoader bootstrapCacheLoader, int maxElementsOnDisk)` 1.2.4 Constructor The `ConfigurationFactory` and clients can create these.
`Cache(java.lang.String name, int maxElementsInMemory, MemoryStoreEvictionPolicy memoryStoreEvictionPolicy, boolean overflowToDisk, java.lang.String diskStorePath, boolean eternal, long timeToLiveSeconds, long timeToIdleSeconds, boolean diskPersistent, long diskExpiryThreadIntervalSeconds, RegisteredEventListeners registeredEventListeners, BootstrapCacheLoader bootstrapCacheLoader, int maxElementsOnDisk, int diskSpoolBufferSizeMB)` 1.2.4 Constructor The `ConfigurationFactory` and clients can create these.

Method Summary
`(package private) edu.emory.mathcs.backport.java.util.concurrent.Future`	`asynchronousLoad(java.lang.Object key, CacheLoader specificLoader, java.lang.Object argument)` Does the asynchronous loading.
`(package private) edu.emory.mathcs.backport.java.util.concurrent.Future`	`asynchronousLoadAll(java.util.Collection keys, java.lang.Object argument)` Does the asynchronous loading.
`void`	`bootstrap()` Bootstrap command.
`long`	`calculateInMemorySize()` Gets the size of the memory store for this cache.
`void`	`clearStatistics()` Resets statistics counters back to 0.
`java.lang.Object`	`clone()` Clones a cache.
`protected Store`	`createDiskStore()` Creates a disk store when either: overflowToDisk is enabled diskPersistent is enabled
`void`	`dispose()` Starts an orderly shutdown of the Cache.
`boolean`	`equals(java.lang.Object object)` An equals method which follows the contract of `Object.equals(Object)` An Cache is equal to another one if it implements Ehcache and has the same GUID.
`void`	`evictExpiredElements()` Causes all elements stored in the Cache to be synchronously checked for expiry, and if expired, evicted.
`void`	`flush()` Flushes all cache items from memory to the disk store, and from the DiskStore to disk.
`Element`	`get(java.lang.Object key)` Gets an element from the cache.
`Element`	`get(java.io.Serializable key)` Gets an element from the cache.
`java.util.Map`	`getAllWithLoader(java.util.Collection keys, java.lang.Object loaderArgument)` Warning: This method is related to the JSR107 specification, which is in draft.
`float`	`getAverageGetTime()` The average get time in ms.
`BootstrapCacheLoader`	`getBootstrapCacheLoader()` Accessor for the BootstrapCacheLoader associated with this cache.
`CacheConfiguration`	`getCacheConfiguration()` Gets the cache configuration this cache was created with.
`RegisteredEventListeners`	`getCacheEventNotificationService()` Use this to access the service in order to register and unregister listeners
`CacheExceptionHandler`	`getCacheExceptionHandler()` Gets the ExceptionHandler on this Cache, or null if there isn't one.
`CacheLoader`	`getCacheLoader()` Gets the CacheLoader registered in this cache
`CacheManager`	`getCacheManager()` Gets the CacheManager managing this cache.
`long`	`getDiskExpiryThreadIntervalSeconds()` Deprecated. Get this from the configuration
`(package private) Store`	`getDiskStore()` Gets the internal DiskStore.
`int`	`getDiskStoreHitCount()` Deprecated. Use `Statistics`
`int`	`getDiskStoreSize()` Returns the number of elements in the disk store.
`(package private) edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor`	`getExecutorService()`
`java.lang.String`	`getGuid()` The GUID for this cache instance can be used to determine whether two cache instance references are pointing to the same cache.
`int`	`getHitCount()` Deprecated. Use `Statistics`
`java.util.List`	`getKeys()` Returns a list of all element keys in the cache, whether or not they are expired.
`java.util.List`	`getKeysNoDuplicateCheck()` Returns a list of all elements in the cache, whether or not they are expired.
`java.util.List`	`getKeysWithExpiryCheck()` Returns a list of all element keys in the cache.
`int`	`getMaxElementsInMemory()` Deprecated. Get this from the configuration
`int`	`getMaxElementsOnDisk()` Deprecated. Get this from the configuration
`(package private) MemoryStore`	`getMemoryStore()` Gets the internal MemoryStore.
`MemoryStoreEvictionPolicy`	`getMemoryStoreEvictionPolicy()` Deprecated. Get this from the configuration
`int`	`getMemoryStoreHitCount()` Deprecated. Use `Statistics`
`long`	`getMemoryStoreSize()` Returns the number of elements in the memory store.
`int`	`getMissCountExpired()` Deprecated. Use `Statistics`
`int`	`getMissCountNotFound()` Deprecated. Use `Statistics`
`java.lang.String`	`getName()` Gets the cache name.
`Element`	`getQuiet(java.lang.Object key)` Gets an element from the cache, without updating Element statistics.
`Element`	`getQuiet(java.io.Serializable key)` Gets an element from the cache, without updating Element statistics.
`int`	`getSize()` Gets the size of the cache.
`Statistics`	`getStatistics()` Gets an immutable Statistics object representing the Cache statistics at the time. Note, the `getSize()` method will have the same value as the size reported by Statistics for the statistics accuracy of `Statistics.STATISTICS_ACCURACY_BEST_EFFORT`.
`int`	`getStatisticsAccuracy()` Accurately measuring statistics can be expensive.
`Status`	`getStatus()` Gets the status attribute of the Cache.
`long`	`getTimeToIdleSeconds()` Deprecated. Get this from the configuration
`long`	`getTimeToLiveSeconds()` Deprecated. Get this from the configuration
`Element`	`getWithLoader(java.lang.Object key, CacheLoader loader, java.lang.Object loaderArgument)` Warning: This method is related to the JSR107 specification, which is in draft.
`int`	`hashCode()` Returns a hash code value for the object.
`void`	`initialise()` Newly created caches do not have a `MemoryStore` or a `DiskStore`.
`boolean`	`isDisabled()` Whether this cache is disabled.
`boolean`	`isDiskPersistent()` Deprecated. Get this from the configuration *
`protected boolean`	`isDiskStore()` Whether this cache uses a disk store
`boolean`	`isElementInMemory(java.lang.Object key)` Whether an Element is stored in the cache in Memory, indicating a very low cost of retrieval.
`boolean`	`isElementInMemory(java.io.Serializable key)` Whether an Element is stored in the cache in Memory, indicating a very low cost of retrieval.
`boolean`	`isElementOnDisk(java.lang.Object key)` Whether an Element is stored in the cache on Disk, indicating a higher cost of retrieval.
`boolean`	`isElementOnDisk(java.io.Serializable key)` Whether an Element is stored in the cache on Disk, indicating a higher cost of retrieval.
`boolean`	`isEternal()` Deprecated. Get this from the configuration
`boolean`	`isExpired(Element element)` Checks whether this cache element has expired.
`boolean`	`isKeyInCache(java.lang.Object key)` An inexpensive check to see if the key exists in the cache.
`boolean`	`isOverflowToDisk()` Deprecated. Get this from the configuration
`boolean`	`isValueInCache(java.lang.Object value)` An extremely expensive check to see if the value exists in the cache.
`void`	`load(java.lang.Object key)` Warning: This method is related to the JSR107 specification, which is in draft.
`void`	`loadAll(java.util.Collection keys, java.lang.Object argument)` Warning: This method is related to the JSR107 specification, which is in draft.
`void`	`put(Element element)` Put an element in the cache.
`void`	`put(Element element, boolean doNotNotifyCacheReplicators)` Put an element in the cache.
`void`	`putQuiet(Element element)` Put an element in the cache, without updating statistics, or updating listeners.
`void`	`registerCacheExtension(CacheExtension cacheExtension)` Register a `CacheExtension` with the cache.
`boolean`	`remove(java.lang.Object key)` Removes an `Element` from the Cache.
`boolean`	`remove(java.lang.Object key, boolean doNotNotifyCacheReplicators)` Removes an `Element` from the Cache.
`boolean`	`remove(java.io.Serializable key)` Removes an `Element` from the Cache.
`boolean`	`remove(java.io.Serializable key, boolean doNotNotifyCacheReplicators)` Removes an `Element` from the Cache.
`void`	`removeAll()` Removes all cached items.
`void`	`removeAll(boolean doNotNotifyCacheReplicators)` Removes all cached items.
`boolean`	`removeQuiet(java.lang.Object key)` Removes an `Element` from the Cache, without notifying listeners.
`boolean`	`removeQuiet(java.io.Serializable key)` Removes an `Element` from the Cache, without notifying listeners.
`void`	`setBootstrapCacheLoader(BootstrapCacheLoader bootstrapCacheLoader)` Sets the bootstrap cache loader.
`void`	`setCacheExceptionHandler(CacheExceptionHandler cacheExceptionHandler)` Sets an ExceptionHandler on the Cache.
`void`	`setCacheLoader(CacheLoader cacheLoader)` Setter for the CacheLoader.
`void`	`setCacheManager(CacheManager cacheManager)` For use by CacheManager.
`void`	`setDisabled(boolean disabled)` Disables or enables this cache.
`void`	`setDiskStorePath(java.lang.String diskStorePath)` DiskStore paths can conflict between CacheManager instances.
`void`	`setName(java.lang.String name)` Sets the cache name which will name.
`void`	`setStatisticsAccuracy(int statisticsAccuracy)` Sets the statistics accuracy.
`java.lang.String`	`toString()` Returns a `String` representation of `Cache`.
`void`	`unregisterCacheExtension(CacheExtension cacheExtension)` Unregister a `CacheExtension` with the cache.

Methods inherited from class java.lang.Object
`finalize, getClass, notify, notifyAll, wait, wait, wait`

Field Detail

DEFAULT_CACHE_NAME

public static final java.lang.String DEFAULT_CACHE_NAME

A reserved word for cache names. It denotes a default configuration which is applied to caches created without configuration.

See Also:: Constant Field Values

NET_SF_EHCACHE_DISABLED

public static final java.lang.String NET_SF_EHCACHE_DISABLED

System Property based method of disabling ehcache. If disabled no elements will be added to a cache.

Set the property "net.sf.ehcache.disabled=true" to disable ehcache.

This can easily be done using java -Dnet.sf.ehcache.disabled=true in the command line.

See Also:: Constant Field Values

DEFAULT_EXPIRY_THREAD_INTERVAL_SECONDS

public static final long DEFAULT_EXPIRY_THREAD_INTERVAL_SECONDS

The default interval between runs of the expiry thread.

See Also:: Constant Field Values

Constructor Detail

Cache

public Cache(java.lang.String name,
             int maxElementsInMemory,
             boolean overflowToDisk,
             boolean eternal,
             long timeToLiveSeconds,
             long timeToIdleSeconds)

1.0 Constructor.

The ConfigurationFactory and clients can create these.

A client can specify their own settings here and pass the Cache object into CacheManager.addCache(java.lang.String) to specify parameters other than the defaults.

Only the CacheManager can initialise them.

This constructor creates disk stores, if specified, that do not persist between restarts.

The default expiry thread interval of 120 seconds is used. This is the interval between runs of the expiry thread, where it checks the disk store for expired elements. It is not the the timeToLiveSeconds.

Parameters:: name - the name of the cache. Note that "default" is a reserved name for the defaultCache.; maxElementsInMemory - the maximum number of elements in memory, before they are evicted; overflowToDisk - whether to use the disk store; eternal - whether the elements in the cache are eternal, i.e. never expire; timeToLiveSeconds - the default amount of time to live for an element from its creation date; timeToIdleSeconds - the default amount of time to live for an element from its last accessed or modified date
Since:: 1.0

Cache

public Cache(java.lang.String name,
             int maxElementsInMemory,
             boolean overflowToDisk,
             boolean eternal,
             long timeToLiveSeconds,
             long timeToIdleSeconds,
             boolean diskPersistent,
             long diskExpiryThreadIntervalSeconds)

1.1 Constructor.

The ConfigurationFactory and clients can create these.

A client can specify their own settings here and pass the Cache object into CacheManager.addCache(java.lang.String) to specify parameters other than the defaults.

Only the CacheManager can initialise them.

Parameters:: name - the name of the cache. Note that "default" is a reserved name for the defaultCache.; maxElementsInMemory - the maximum number of elements in memory, before they are evicted; overflowToDisk - whether to use the disk store; eternal - whether the elements in the cache are eternal, i.e. never expire; timeToLiveSeconds - the default amount of time to live for an element from its creation date; timeToIdleSeconds - the default amount of time to live for an element from its last accessed or modified date; diskPersistent - whether to persist the cache to disk between JVM restarts; diskExpiryThreadIntervalSeconds - how often to run the disk store expiry thread. A large number of 120 seconds plus is recommended
Since:: 1.1

Cache

public Cache(java.lang.String name,
             int maxElementsInMemory,
             MemoryStoreEvictionPolicy memoryStoreEvictionPolicy,
             boolean overflowToDisk,
             java.lang.String diskStorePath,
             boolean eternal,
             long timeToLiveSeconds,
             long timeToIdleSeconds,
             boolean diskPersistent,
             long diskExpiryThreadIntervalSeconds,
             RegisteredEventListeners registeredEventListeners)

1.2 Constructor

The ConfigurationFactory and clients can create these.

A client can specify their own settings here and pass the Cache object into CacheManager.addCache(java.lang.String) to specify parameters other than the defaults.

Only the CacheManager can initialise them.

Parameters:: name - the name of the cache. Note that "default" is a reserved name for the defaultCache.; maxElementsInMemory - the maximum number of elements in memory, before they are evicted; memoryStoreEvictionPolicy - one of LRU, LFU and FIFO. Optionally null, in which case it will be set to LRU.; overflowToDisk - whether to use the disk store; diskStorePath - this parameter is ignored. CacheManager sets it using setter injection.; eternal - whether the elements in the cache are eternal, i.e. never expire; timeToLiveSeconds - the default amount of time to live for an element from its creation date; timeToIdleSeconds - the default amount of time to live for an element from its last accessed or modified date; diskPersistent - whether to persist the cache to disk between JVM restarts; diskExpiryThreadIntervalSeconds - how often to run the disk store expiry thread. A large number of 120 seconds plus is recommended; registeredEventListeners - a notification service. Optionally null, in which case a new one with no registered listeners will be created.
Since:: 1.2

Cache

public Cache(java.lang.String name,
             int maxElementsInMemory,
             MemoryStoreEvictionPolicy memoryStoreEvictionPolicy,
             boolean overflowToDisk,
             java.lang.String diskStorePath,
             boolean eternal,
             long timeToLiveSeconds,
             long timeToIdleSeconds,
             boolean diskPersistent,
             long diskExpiryThreadIntervalSeconds,
             RegisteredEventListeners registeredEventListeners,
             BootstrapCacheLoader bootstrapCacheLoader)

1.2.1 Constructor

The ConfigurationFactory and clients can create these.

A client can specify their own settings here and pass the Cache object into CacheManager.addCache(java.lang.String) to specify parameters other than the defaults.

Only the CacheManager can initialise them.

Parameters:: name - the name of the cache. Note that "default" is a reserved name for the defaultCache.; maxElementsInMemory - the maximum number of elements in memory, before they are evicted; memoryStoreEvictionPolicy - one of LRU, LFU and FIFO. Optionally null, in which case it will be set to LRU.; overflowToDisk - whether to use the disk store; diskStorePath - this parameter is ignored. CacheManager sets it using setter injection.; eternal - whether the elements in the cache are eternal, i.e. never expire; timeToLiveSeconds - the default amount of time to live for an element from its creation date; timeToIdleSeconds - the default amount of time to live for an element from its last accessed or modified date; diskPersistent - whether to persist the cache to disk between JVM restarts; diskExpiryThreadIntervalSeconds - how often to run the disk store expiry thread. A large number of 120 seconds plus is recommended; registeredEventListeners - a notification service. Optionally null, in which case a new one with no registered listeners will be created.; bootstrapCacheLoader - the BootstrapCacheLoader to use to populate the cache when it is first initialised. Null if none is required.
Since:: 1.2.1

Cache

public Cache(java.lang.String name,
             int maxElementsInMemory,
             MemoryStoreEvictionPolicy memoryStoreEvictionPolicy,
             boolean overflowToDisk,
             java.lang.String diskStorePath,
             boolean eternal,
             long timeToLiveSeconds,
             long timeToIdleSeconds,
             boolean diskPersistent,
             long diskExpiryThreadIntervalSeconds,
             RegisteredEventListeners registeredEventListeners,
             BootstrapCacheLoader bootstrapCacheLoader,
             int maxElementsOnDisk)

1.2.4 Constructor

The ConfigurationFactory and clients can create these.

A client can specify their own settings here and pass the Cache object into CacheManager.addCache(java.lang.String) to specify parameters other than the defaults.

Only the CacheManager can initialise them.

Parameters:: name - the name of the cache. Note that "default" is a reserved name for the defaultCache.; maxElementsInMemory - the maximum number of elements in memory, before they are evicted; memoryStoreEvictionPolicy - one of LRU, LFU and FIFO. Optionally null, in which case it will be set to LRU.; overflowToDisk - whether to use the disk store; diskStorePath - this parameter is ignored. CacheManager sets it using setter injection.; eternal - whether the elements in the cache are eternal, i.e. never expire; timeToLiveSeconds - the default amount of time to live for an element from its creation date; timeToIdleSeconds - the default amount of time to live for an element from its last accessed or modified date; diskPersistent - whether to persist the cache to disk between JVM restarts; diskExpiryThreadIntervalSeconds - how often to run the disk store expiry thread. A large number of 120 seconds plus is recommended; registeredEventListeners - a notification service. Optionally null, in which case a new one with no registered listeners will be created.; bootstrapCacheLoader - the BootstrapCacheLoader to use to populate the cache when it is first initialised. Null if none is required.
Since:: 1.2.4

Cache

public Cache(java.lang.String name,
             int maxElementsInMemory,
             MemoryStoreEvictionPolicy memoryStoreEvictionPolicy,
             boolean overflowToDisk,
             java.lang.String diskStorePath,
             boolean eternal,
             long timeToLiveSeconds,
             long timeToIdleSeconds,
             boolean diskPersistent,
             long diskExpiryThreadIntervalSeconds,
             RegisteredEventListeners registeredEventListeners,
             BootstrapCacheLoader bootstrapCacheLoader,
             int maxElementsOnDisk,
             int diskSpoolBufferSizeMB)

1.2.4 Constructor

The ConfigurationFactory and clients can create these.

A client can specify their own settings here and pass the Cache object into CacheManager.addCache(java.lang.String) to specify parameters other than the defaults.

Only the CacheManager can initialise them.

Parameters:: name - the name of the cache. Note that "default" is a reserved name for the defaultCache.; maxElementsInMemory - the maximum number of elements in memory, before they are evicted; memoryStoreEvictionPolicy - one of LRU, LFU and FIFO. Optionally null, in which case it will be set to LRU.; overflowToDisk - whether to use the disk store; diskStorePath - this parameter is ignored. CacheManager sets it using setter injection.; eternal - whether the elements in the cache are eternal, i.e. never expire; timeToLiveSeconds - the default amount of time to live for an element from its creation date; timeToIdleSeconds - the default amount of time to live for an element from its last accessed or modified date; diskPersistent - whether to persist the cache to disk between JVM restarts; diskExpiryThreadIntervalSeconds - how often to run the disk store expiry thread. A large number of 120 seconds plus is recommended; registeredEventListeners - a notification service. Optionally null, in which case a new one with no registered listeners will be created.; bootstrapCacheLoader - the BootstrapCacheLoader to use to populate the cache when it is first initialised. Null if none is required.; diskSpoolBufferSizeMB - the amount of memory to allocate the write buffer for puts to the DiskStore.
Since:: 1.2.4

Method Detail

initialise

public void initialise()

Newly created caches do not have a MemoryStore or a DiskStore.

This method creates those and makes the cache ready to accept elements

Specified by:: initialise in interface Ehcache

createDiskStore

protected Store createDiskStore()

Creates a disk store when either:

overflowToDisk is enabled
diskPersistent is enabled

isDiskStore

protected boolean isDiskStore()

Whether this cache uses a disk store

Returns:: true if the cache either overflows to disk or is disk persistent

bootstrap

public void bootstrap()

Bootstrap command. This must be called after the Cache is intialised, during CacheManager initialisation. If loads are synchronous, they will complete before the CacheManager initialise completes, otherwise they will happen in the background.

Specified by:: bootstrap in interface Ehcache

put

public final void put(Element element)
               throws java.lang.IllegalArgumentException,
                      java.lang.IllegalStateException,
                      CacheException

Put an element in the cache.

Resets the access statistics on the element, which would be the case if it has previously been gotten from a cache, and is now being put back.

Also notifies the CacheEventListener that:

the element was put, but only if the Element was actually put.
if the element exists in the cache, that an update has occurred, even if the element would be expired if it was requested

Synchronization is handled within the method.

Caches which use synchronous replication can throw RemoteCacheException here if the replication to the cluster fails. This exception should be caught in those cirucmstances.

Specified by:: put in interface Ehcache

Parameters:: element - An object. If Serializable it can fully participate in replication and the DiskStore.
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; java.lang.IllegalArgumentException - if the element is null; CacheException

put

public final void put(Element element,
                      boolean doNotNotifyCacheReplicators)
               throws java.lang.IllegalArgumentException,
                      java.lang.IllegalStateException,
                      CacheException

Put an element in the cache.

Resets the access statistics on the element, which would be the case if it has previously been gotten from a cache, and is now being put back.

Also notifies the CacheEventListener that:

the element was put, but only if the Element was actually put.
if the element exists in the cache, that an update has occurred, even if the element would be expired if it was requested

Synchronization is handled within the method.

Caches which use synchronous replication can throw RemoteCacheException here if the replication to the cluster fails. This exception should be caught in those cirucmstances.

Specified by:: put in interface Ehcache

Parameters:: element - An object. If Serializable it can fully participate in replication and the DiskStore.; doNotNotifyCacheReplicators - whether the put is coming from a doNotNotifyCacheReplicators cache peer, in which case this put should not initiate a further notification to doNotNotifyCacheReplicators cache peers
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; java.lang.IllegalArgumentException - if the element is null; CacheException

putQuiet

public final void putQuiet(Element element)
                    throws java.lang.IllegalArgumentException,
                           java.lang.IllegalStateException,
                           CacheException

Put an element in the cache, without updating statistics, or updating listeners. This is meant to be used in conjunction with getQuiet(java.io.Serializable). Synchronization is handled within the method.

Caches which use synchronous replication can throw RemoteCacheException here if the replication to the cluster fails. This exception should be caught in those cirucmstances.

Specified by:: putQuiet in interface Ehcache

Parameters:: element - An object. If Serializable it can fully participate in replication and the DiskStore.
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; java.lang.IllegalArgumentException - if the element is null; CacheException

get

public final Element get(java.io.Serializable key)
                  throws java.lang.IllegalStateException,
                         CacheException

Gets an element from the cache. Updates Element Statistics

Note that the Element's lastAccessTime is always the time of this get. Use getQuiet(Object) to peak into the Element to see its last access time with get

Synchronization is handled within the method.

Specified by:: get in interface Ehcache

Parameters:: key - a serializable value
Returns:: the element, or null, if it does not exist.
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; CacheException
See Also:: isExpired(net.sf.ehcache.Element)

get

public final Element get(java.lang.Object key)
                  throws java.lang.IllegalStateException,
                         CacheException

Gets an element from the cache. Updates Element Statistics

Note that the Element's lastAccessTime is always the time of this get. Use getQuiet(Object) to peak into the Element to see its last access time with get

Synchronization is handled within the method.

Specified by:: get in interface Ehcache

Parameters:: key - an Object value
Returns:: the element, or null, if it does not exist.
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; CacheException
Since:: 1.2
See Also:: isExpired(net.sf.ehcache.Element)

getWithLoader

public Element getWithLoader(java.lang.Object key,
                             CacheLoader loader,
                             java.lang.Object loaderArgument)
                      throws CacheException

Warning: This method is related to the JSR107 specification, which is in draft. It is subject to change without notice.

This method will return, from the cache, the Element associated with the argument "key".

If the Element is not in the cache, the associated cache loader will be called. That is either the CacheLoader passed in, or if null, the one associated with the cache. If both are null, no load is performed and null is returned.

If the loader decides to assign a null value to the Element, an Element with a null value is created and stored in the cache.

Because this method may take a long time to complete, it is not synchronized. The underlying cache operations are synchronized.

Specified by:: getWithLoader in interface Ehcache

Parameters:: key - key whose associated value is to be returned.; loader - the override loader to use. If null, the cache's default loader will be used; loaderArgument - an argument to pass to the CacheLoader.
Returns:: an element if it existed or could be loaded, otherwise null
Throws:: CacheException

load

public void load(java.lang.Object key)
          throws CacheException

Warning: This method is related to the JSR107 specification, which is in draft. It is subject to change without notice.

The load method provides a means to "pre load" the cache. This method will, asynchronously, load the specified object into the cache using the associated cacheloader. If the object already exists in the cache, no action is taken. If no loader is associated with the object, no object will be loaded into the cache. If a problem is encountered during the retrieving or loading of the object, an exception should be logged. If the "arg" argument is set, the arg object will be passed to the CacheLoader.load method. The cache will not dereference the object. If no "arg" value is provided a null will be passed to the load method. The storing of null values in the cache is permitted, however, the get method will not distinguish returning a null stored in the cache and not finding the object in the cache. In both cases a null is returned.

The Ehcache native API provides similar functionality to loaders using the decorator SelfPopulatingCache

Specified by:: load in interface Ehcache

Parameters:: key - key whose associated value to be loaded using the associated cacheloader if this cache doesn't contain it.
Throws:: CacheException

getAllWithLoader

public java.util.Map getAllWithLoader(java.util.Collection keys,
                                      java.lang.Object loaderArgument)
                               throws CacheException

Warning: This method is related to the JSR107 specification, which is in draft. It is subject to change without notice.

The getAll method will return, from the cache, a Map of the objects associated with the Collection of keys in argument "keys". If the objects are not in the cache, the associated cache loader will be called. If no loader is associated with an object, a null is returned. If a problem is encountered during the retrieving or loading of the objects, an exception will be thrown. If the "arg" argument is set, the arg object will be passed to the CacheLoader.loadAll method. The cache will not dereference the object. If no "arg" value is provided a null will be passed to the loadAll method. The storing of null values in the cache is permitted, however, the get method will not distinguish returning a null stored in the cache and not finding the object in the cache. In both cases a null is returned.

Note. If the getAll exceeds the maximum cache size, the returned map will necessarily be less than the number specified.

Because this method may take a long time to complete, it is not synchronized. The underlying cache operations are synchronized.

The constructs package provides similar functionality using the decorator SelfPopulatingCache

Specified by:: getAllWithLoader in interface Ehcache

Parameters:: keys - a collection of keys to be returned/loaded; loaderArgument - an argument to pass to the CacheLoader.
Returns:: a Map populated from the Cache. If there are no elements, an empty Map is returned.
Throws:: CacheException

loadAll

public void loadAll(java.util.Collection keys,
                    java.lang.Object argument)
             throws CacheException

Warning: This method is related to the JSR107 specification, which is in draft. It is subject to change without notice.

The loadAll method provides a means to "pre load" objects into the cache. This method will, asynchronously, load the specified objects into the cache using the associated cache loader. If the an object already exists in the cache, no action is taken. If no loader is associated with the object, no object will be loaded into the cache. If a problem is encountered during the retrieving or loading of the objects, an exception (to be defined) should be logged. The getAll method will return, from the cache, a Map of the objects associated with the Collection of keys in argument "keys". If the objects are not in the cache, the associated cache loader will be called. If no loader is associated with an object, a null is returned. If a problem is encountered during the retrieving or loading of the objects, an exception (to be defined) will be thrown. If the "arg" argument is set, the arg object will be passed to the CacheLoader.loadAll method. The cache will not dereference the object. If no "arg" value is provided a null will be passed to the loadAll method.

keys - collection of the keys whose associated values to be loaded into this cache by using the associated cacheloader if this cache doesn't contain them.

The Ehcache native API provides similar functionality to loaders using the decorator SelfPopulatingCache

Specified by:: loadAll in interface Ehcache

Throws:: CacheException

getQuiet

public final Element getQuiet(java.io.Serializable key)
                       throws java.lang.IllegalStateException,
                              CacheException

Gets an element from the cache, without updating Element statistics. Cache statistics are still updated.

Synchronization is handled within the method.

Specified by:: getQuiet in interface Ehcache

Parameters:: key - a serializable value
Returns:: the element, or null, if it does not exist.
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; CacheException
See Also:: isExpired(net.sf.ehcache.Element)

getQuiet

public final Element getQuiet(java.lang.Object key)
                       throws java.lang.IllegalStateException,
                              CacheException

Gets an element from the cache, without updating Element statistics. Cache statistics are not updated.

Synchronization is handled within the method.

Specified by:: getQuiet in interface Ehcache

Parameters:: key - a serializable value
Returns:: the element, or null, if it does not exist.
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; CacheException
Since:: 1.2
See Also:: isExpired(net.sf.ehcache.Element)

getKeys

public final java.util.List getKeys()
                             throws java.lang.IllegalStateException,
                                    CacheException

Returns a list of all element keys in the cache, whether or not they are expired.

The returned keys are unique and can be considered a set.

The List returned is not live. It is a copy.

The time taken is O(n). On a single cpu 1.8Ghz P4, approximately 8ms is required for each 1000 entries.

Specified by:: getKeys in interface Ehcache

Returns:: a list of Object keys
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; CacheException

getKeysWithExpiryCheck

public final java.util.List getKeysWithExpiryCheck()
                                            throws java.lang.IllegalStateException,
                                                   CacheException

Returns a list of all element keys in the cache. Only keys of non-expired elements are returned.

The returned keys are unique and can be considered a set.

The List returned is not live. It is a copy.

The time taken is O(n), where n is the number of elements in the cache. On a 1.8Ghz P4, the time taken is approximately 200ms per 1000 entries. This method is not syncrhonized, because it relies on a non-live list returned from getKeys() , which is synchronised, and which takes 8ms per 1000 entries. This way cache liveness is preserved, even if this method is very slow to return.

Consider whether your usage requires checking for expired keys. Because this method takes so long, depending on cache settings, the list could be quite out of date by the time you get it.

Specified by:: getKeysWithExpiryCheck in interface Ehcache

Returns:: a list of Object keys
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; CacheException

getKeysNoDuplicateCheck

public final java.util.List getKeysNoDuplicateCheck()
                                             throws java.lang.IllegalStateException

Returns a list of all elements in the cache, whether or not they are expired.

The returned keys are not unique and may contain duplicates. If the cache is only using the memory store, the list will be unique. If the disk store is being used as well, it will likely contain duplicates, because of the internal store design.

The List returned is not live. It is a copy.

The time taken is O(log n). On a single cpu 1.8Ghz P4, approximately 6ms is required for 1000 entries and 36 for 50000.

This is the fastest getKeys method

Specified by:: getKeysNoDuplicateCheck in interface Ehcache

Returns:: a list of Object keys
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE

remove

public final boolean remove(java.io.Serializable key)
                     throws java.lang.IllegalStateException

Removes an Element from the Cache. This also removes it from any stores it may be in.

Also notifies the CacheEventListener after the element was removed.

Synchronization is handled within the method.

Caches which use synchronous replication can throw RemoteCacheException here if the replication to the cluster fails. This exception should be caught in those cirucmstances.

Specified by:: remove in interface Ehcache

Parameters:: key - the element key to operate on
Returns:: true if the element was removed, false if it was not found in the cache
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE

remove

public final boolean remove(java.lang.Object key)
                     throws java.lang.IllegalStateException

Removes an Element from the Cache. This also removes it from any stores it may be in.

Also notifies the CacheEventListener after the element was removed, but only if an Element with the key actually existed.

Synchronization is handled within the method.

Caches which use synchronous replication can throw RemoteCacheException here if the replication to the cluster fails. This exception should be caught in those cirucmstances.

Specified by:: remove in interface Ehcache

Parameters:: key - the element key to operate on
Returns:: true if the element was removed, false if it was not found in the cache
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE
Since:: 1.2

remove

public final boolean remove(java.io.Serializable key,
                            boolean doNotNotifyCacheReplicators)
                     throws java.lang.IllegalStateException

Removes an Element from the Cache. This also removes it from any stores it may be in.

Also notifies the CacheEventListener after the element was removed, but only if an Element with the key actually existed.

Synchronization is handled within the method.

Caches which use synchronous replication can throw RemoteCacheException here if the replication to the cluster fails. This exception should be caught in those cirucmstances.

Specified by:: remove in interface Ehcache

Parameters:: key - the element key to operate on; doNotNotifyCacheReplicators - whether the put is coming from a doNotNotifyCacheReplicators cache peer, in which case this put should not initiate a further notification to doNotNotifyCacheReplicators cache peers
Returns:: true if the element was removed, false if it was not found in the cache
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE

remove

public final boolean remove(java.lang.Object key,
                            boolean doNotNotifyCacheReplicators)
                     throws java.lang.IllegalStateException

Removes an Element from the Cache. This also removes it from any stores it may be in.

Also notifies the CacheEventListener after the element was removed, but only if an Element with the key actually existed.

Synchronization is handled within the method.

Specified by:: remove in interface Ehcache

Parameters:: key - the element key to operate on; doNotNotifyCacheReplicators - whether the put is coming from a doNotNotifyCacheReplicators cache peer, in which case this put should not initiate a further notification to doNotNotifyCacheReplicators cache peers
Returns:: true if the element was removed, false if it was not found in the cache
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE

removeQuiet

public final boolean removeQuiet(java.io.Serializable key)
                          throws java.lang.IllegalStateException

Removes an Element from the Cache, without notifying listeners. This also removes it from any stores it may be in.

Synchronization is handled within the method.

Specified by:: removeQuiet in interface Ehcache

Parameters:: key - the element key to operate on
Returns:: true if the element was removed, false if it was not found in the cache
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE

removeQuiet

public final boolean removeQuiet(java.lang.Object key)
                          throws java.lang.IllegalStateException

Removes an Element from the Cache, without notifying listeners. This also removes it from any stores it may be in.

Synchronization is handled within the method.

Caches which use synchronous replication can throw RemoteCacheException here if the replication to the cluster fails. This exception should be caught in those cirucmstances.

Specified by:: removeQuiet in interface Ehcache

Parameters:: key - the element key to operate on
Returns:: true if the element was removed, false if it was not found in the cache
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE
Since:: 1.2

removeAll

public void removeAll()
               throws java.lang.IllegalStateException,
                      CacheException

Removes all cached items. Synchronization is handled within the method.

Caches which use synchronous replication can throw RemoteCacheException here if the replication to the cluster fails. This exception should be caught in those cirucmstances.

Specified by:: removeAll in interface Ehcache

Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; CacheException

removeAll

public void removeAll(boolean doNotNotifyCacheReplicators)
               throws java.lang.IllegalStateException,
                      CacheException

Removes all cached items. Synchronization is handled within the method.

Caches which use synchronous replication can throw RemoteCacheException here if the replication to the cluster fails. This exception should be caught in those cirucmstances.

Specified by:: removeAll in interface Ehcache

Parameters:: doNotNotifyCacheReplicators - whether the put is coming from a doNotNotifyCacheReplicators cache peer, in which case this put should not initiate a further notification to doNotNotifyCacheReplicators cache peers
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; CacheException

dispose

public void dispose()
             throws java.lang.IllegalStateException

Starts an orderly shutdown of the Cache. Steps are:

Completes any outstanding CacheLoader loads.
Disposes any cache extensions.
Disposes any cache event listeners. The listeners normally complete, so for example distributed caching operations will complete.
Flushes all cache items from memory to the disk store, if any
changes status to shutdown, so that any cache operations after this point throw IllegalStateException

This method should be invoked only by CacheManager, as a cache's lifecycle is bound into that of it's cache manager.

Specified by:: dispose in interface Ehcache

Throws:: java.lang.IllegalStateException - if the cache is already Status.STATUS_SHUTDOWN

getCacheConfiguration

public CacheConfiguration getCacheConfiguration()

Gets the cache configuration this cache was created with.

Things like listeners that are added dynamically are excluded.

Specified by:: getCacheConfiguration in interface Ehcache

flush

public final void flush()
                 throws java.lang.IllegalStateException,
                        CacheException

Flushes all cache items from memory to the disk store, and from the DiskStore to disk.

Specified by:: flush in interface Ehcache

Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; CacheException

getSize

public final int getSize()
                  throws java.lang.IllegalStateException,
                         CacheException

Gets the size of the cache. This is a subtle concept. See below.

The size is the number of Elements in the MemoryStore plus the number of Elements in the DiskStore.

This number is the actual number of elements, including expired elements that have not been removed.

Expired elements are removed from the the memory store when getting an expired element, or when attempting to spool an expired element to disk.

Expired elements are removed from the disk store when getting an expired element, or when the expiry thread runs, which is once every five minutes.

To get an exact size, which would exclude expired elements, use getKeysWithExpiryCheck().size(), although see that method for the approximate time that would take.

To get a very fast result, use getKeysNoDuplicateCheck().size(). If the disk store is being used, there will be some duplicates.

Specified by:: getSize in interface Ehcache

Returns:: The size value
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; CacheException

calculateInMemorySize

public final long calculateInMemorySize()
                                 throws java.lang.IllegalStateException,
                                        CacheException

Gets the size of the memory store for this cache. This method relies on calculating Serialized sizes. If the Element values are not Serializable they will show as zero.

Warning: This method can be very expensive to run. Allow approximately 1 second per 1MB of entries. Running this method could create liveness problems because the object lock is held for a long period

Specified by:: calculateInMemorySize in interface Ehcache

Returns:: the approximate size of the memory store in bytes
Throws:: java.lang.IllegalStateException; CacheException

getMemoryStoreSize

public final long getMemoryStoreSize()
                              throws java.lang.IllegalStateException

Returns the number of elements in the memory store.

Specified by:: getMemoryStoreSize in interface Ehcache

Returns:: the number of elements in the memory store
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE

getDiskStoreSize

public final int getDiskStoreSize()
                           throws java.lang.IllegalStateException

Returns the number of elements in the disk store.

Specified by:: getDiskStoreSize in interface Ehcache

Returns:: the number of elements in the disk store.
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE

getStatus

public final Status getStatus()

Gets the status attribute of the Cache.

Specified by:: getStatus in interface Ehcache

Returns:: The status value from the Status enum class

getHitCount

public final int getHitCount()

Deprecated. Use Statistics

The number of times a requested item was found in the cache.

The internal representation of this statistic has been changed to a long to cater for real world situations when an int is not sufficient to hold it. If the statistic is larger than Integer.MAX_VALUE a nonsensical value will be returned. Use Statistics which contains this statistic.

Returns:: the number of times a requested item was found in the cache

getMemoryStoreHitCount

public final int getMemoryStoreHitCount()

Deprecated. Use Statistics

Number of times a requested item was found in the Memory Store.

Returns:: Number of times a requested item was found in the Memory Store.

getDiskStoreHitCount

public final int getDiskStoreHitCount()

Deprecated. Use Statistics

Number of times a requested item was found in the Disk Store.

getMissCountNotFound

public final int getMissCountNotFound()

Deprecated. Use Statistics

Number of times a requested element was not found in the cache. This may be because it expired, in which case this will also be recorded in getMissCountExpired(), or because it was simply not there.

getMissCountExpired

public final int getMissCountExpired()

Deprecated. Use Statistics

Number of times a requested element was found but was expired.

getName

public final java.lang.String getName()

Gets the cache name.

Specified by:: getName in interface Ehcache

setName

public final void setName(java.lang.String name)
                   throws java.lang.IllegalArgumentException

Sets the cache name which will name.

Specified by:: setName in interface Ehcache

Parameters:: name - the name of the cache. Should not be null. Should also not contain any '/' characters, as these interfere with distribution
Throws:: java.lang.IllegalArgumentException - if an illegal name is used.

getTimeToIdleSeconds

public final long getTimeToIdleSeconds()

Deprecated. Get this from the configuration

Gets timeToIdleSeconds.

Specified by:: getTimeToIdleSeconds in interface Ehcache

getTimeToLiveSeconds

public final long getTimeToLiveSeconds()

Deprecated. Get this from the configuration

Gets timeToLiveSeconds.

Specified by:: getTimeToLiveSeconds in interface Ehcache

isEternal

public final boolean isEternal()

Deprecated. Get this from the configuration

Are elements eternal.

Specified by:: isEternal in interface Ehcache

isOverflowToDisk

public final boolean isOverflowToDisk()

Deprecated. Get this from the configuration

Does the overflow go to disk.

Specified by:: isOverflowToDisk in interface Ehcache

getMaxElementsInMemory

public final int getMaxElementsInMemory()

Deprecated. Get this from the configuration

Gets the maximum number of elements to hold in memory.

Specified by:: getMaxElementsInMemory in interface Ehcache

getMaxElementsOnDisk

public int getMaxElementsOnDisk()

Deprecated. Get this from the configuration

Gets the maximum number of elements to hold on Disk

Specified by:: getMaxElementsOnDisk in interface Ehcache

getMemoryStoreEvictionPolicy

public final MemoryStoreEvictionPolicy getMemoryStoreEvictionPolicy()

Deprecated. Get this from the configuration

The policy used to evict elements from the MemoryStore. This can be one of:

LRU - least recently used
LFU - least frequently used
FIFO - first in first out, the oldest element by creation time

The default value is LRU

Specified by:: getMemoryStoreEvictionPolicy in interface Ehcache

Since:: 1.2

isDiskPersistent

public final boolean isDiskPersistent()

Deprecated. Get this from the configuration *

Specified by:: isDiskPersistent in interface Ehcache

Returns:: true if the cache overflows to disk and the disk is persistent between restarts

getDiskExpiryThreadIntervalSeconds

public final long getDiskExpiryThreadIntervalSeconds()

Deprecated. Get this from the configuration

Specified by:: getDiskExpiryThreadIntervalSeconds in interface Ehcache

Returns:: the interval between runs of the expiry thread, where it checks the disk store for expired elements. It is not the the timeToLiveSeconds.

toString

public final java.lang.String toString()

Returns a String representation of Cache.

Specified by:: toString in interface Ehcache
Overrides:: toString in class java.lang.Object

isExpired

public final boolean isExpired(Element element)
                        throws java.lang.IllegalStateException,
                               java.lang.NullPointerException

Checks whether this cache element has expired.

The element is expired if:

the idle time is non-zero and has elapsed, unless the cache is eternal; or
the time to live is non-zero and has elapsed, unless the cache is eternal; or
the value of the element is null.

Specified by:: isExpired in interface Ehcache

Parameters:: element - the element to check
Returns:: true if it has expired
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE; java.lang.NullPointerException - if the element is null

clone

public final java.lang.Object clone()
                             throws java.lang.CloneNotSupportedException

Clones a cache. This is only legal if the cache has not been initialized. At that point only primitives have been set and no LruMemoryStore or DiskStore has been created.

A new, empty, RegisteredEventListeners is created on clone.

Specified by:: clone in interface Ehcache
Overrides:: clone in class java.lang.Object

Returns:: an object of type Cache
Throws:: java.lang.CloneNotSupportedException

getDiskStore

final Store getDiskStore()
                  throws java.lang.IllegalStateException

Gets the internal DiskStore.

Returns:: the DiskStore referenced by this cache
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE

getMemoryStore

final MemoryStore getMemoryStore()
                          throws java.lang.IllegalStateException

Gets the internal MemoryStore.

Returns:: the MemoryStore referenced by this cache
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE

getCacheEventNotificationService

public final RegisteredEventListeners getCacheEventNotificationService()

Use this to access the service in order to register and unregister listeners

Specified by:: getCacheEventNotificationService in interface Ehcache

Returns:: the RegisteredEventListeners instance for this cache.

isElementInMemory

public final boolean isElementInMemory(java.io.Serializable key)

Whether an Element is stored in the cache in Memory, indicating a very low cost of retrieval.

Specified by:: isElementInMemory in interface Ehcache

Returns:: true if an element matching the key is found in memory

isElementInMemory

public final boolean isElementInMemory(java.lang.Object key)

Whether an Element is stored in the cache in Memory, indicating a very low cost of retrieval.

Specified by:: isElementInMemory in interface Ehcache

Returns:: true if an element matching the key is found in memory
Since:: 1.2

isElementOnDisk

public final boolean isElementOnDisk(java.io.Serializable key)

Whether an Element is stored in the cache on Disk, indicating a higher cost of retrieval.

Specified by:: isElementOnDisk in interface Ehcache

Returns:: true if an element matching the key is found in the diskStore

isElementOnDisk

public final boolean isElementOnDisk(java.lang.Object key)

Whether an Element is stored in the cache on Disk, indicating a higher cost of retrieval.

Specified by:: isElementOnDisk in interface Ehcache

Returns:: true if an element matching the key is found in the diskStore
Since:: 1.2

getGuid

public final java.lang.String getGuid()

The GUID for this cache instance can be used to determine whether two cache instance references are pointing to the same cache.

Specified by:: getGuid in interface Ehcache

Returns:: the globally unique identifier for this cache instance. This is guaranteed to be unique.
Since:: 1.2

getCacheManager

public final CacheManager getCacheManager()

Gets the CacheManager managing this cache. For a newly created cache this will be null until it has been added to a CacheManager.

Specified by:: getCacheManager in interface Ehcache

Returns:: the manager or null if there is none

clearStatistics

public void clearStatistics()
                     throws java.lang.IllegalStateException

Resets statistics counters back to 0.

Specified by:: clearStatistics in interface Ehcache

Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE

getStatisticsAccuracy

public int getStatisticsAccuracy()

Accurately measuring statistics can be expensive. Returns the current accuracy setting.

Specified by:: getStatisticsAccuracy in interface Ehcache

Returns:: one of Statistics.STATISTICS_ACCURACY_BEST_EFFORT, Statistics.STATISTICS_ACCURACY_GUARANTEED, Statistics.STATISTICS_ACCURACY_NONE

setStatisticsAccuracy

public void setStatisticsAccuracy(int statisticsAccuracy)

Sets the statistics accuracy.

Specified by:: setStatisticsAccuracy in interface Ehcache

Parameters:: statisticsAccuracy - one of Statistics.STATISTICS_ACCURACY_BEST_EFFORT, Statistics.STATISTICS_ACCURACY_GUARANTEED, Statistics.STATISTICS_ACCURACY_NONE

evictExpiredElements

public void evictExpiredElements()

Causes all elements stored in the Cache to be synchronously checked for expiry, and if expired, evicted.

Specified by:: evictExpiredElements in interface Ehcache

isKeyInCache

public boolean isKeyInCache(java.lang.Object key)

An inexpensive check to see if the key exists in the cache.

This method is not synchronized. It is possible that an element may exist in the cache aned be removed before the check gets to it, or vice versa.

Specified by:: isKeyInCache in interface Ehcache

Parameters:: key - the key to check.
Returns:: true if an Element matching the key is found in the cache. No assertions are made about the state of the Element.

isValueInCache

public boolean isValueInCache(java.lang.Object value)

An extremely expensive check to see if the value exists in the cache. This implementation is O(n). Ehcache is not designed for efficient access in this manner.

This method is not synchronized. It is possible that an element may exist in the cache aned be removed before the check gets to it, or vice versa. Because it is slow to execute the probability of that this will have happened.

Specified by:: isValueInCache in interface Ehcache

Parameters:: value - to check for
Returns:: true if an Element matching the key is found in the cache. No assertions are made about the state of the Element.

getStatistics

public Statistics getStatistics()
                         throws java.lang.IllegalStateException

Gets an immutable Statistics object representing the Cache statistics at the time. How the statistics are calculated depends on the statistics accuracy setting. The only aspect of statistics sensitive to the accuracy setting is object size. How that is calculated is discussed below.

Best Effort Size

This result is returned when the statistics accuracy setting is Statistics.STATISTICS_ACCURACY_BEST_EFFORT.

The size is the number of Elements in the MemoryStore plus the number of Elements in the DiskStore.

This number is the actual number of elements, including expired elements that have not been removed. Any duplicates between stores are accounted for.

Expired elements are removed from the the memory store when getting an expired element, or when attempting to spool an expired element to disk.

Expired elements are removed from the disk store when getting an expired element, or when the expiry thread runs, which is once every five minutes.

Guaranteed Accuracy Size

This result is returned when the statistics accuracy setting is Statistics.STATISTICS_ACCURACY_GUARANTEED.

This method accounts for elements which might be expired or duplicated between stores. It take approximately 200ms per 1000 elements to execute.

Fast but non-accurate Size

This result is returned when the statistics accuracy setting is Statistics.STATISTICS_ACCURACY_NONE.

The number given may contain expired elements. In addition if the DiskStore is used it may contain some double counting of elements. It takes 6ms for 1000 elements to execute. Time to execute is O(log n). 50,000 elements take 36ms.

Note, the getSize() method will have the same value as the size reported by Statistics for the statistics accuracy of Statistics.STATISTICS_ACCURACY_BEST_EFFORT.

Specified by:: getStatistics in interface Ehcache

Returns:: the number of elements in the ehcache, with a varying degree of accuracy, depending on accuracy setting.
Throws:: java.lang.IllegalStateException - if the cache is not Status.STATUS_ALIVE

setCacheManager

public void setCacheManager(CacheManager cacheManager)

For use by CacheManager.

Specified by:: setCacheManager in interface Ehcache

Parameters:: cacheManager - the CacheManager for this cache to use.

getBootstrapCacheLoader

public BootstrapCacheLoader getBootstrapCacheLoader()

Accessor for the BootstrapCacheLoader associated with this cache. For testing purposes.

Specified by:: getBootstrapCacheLoader in interface Ehcache

Returns:: the BootstrapCacheLoader to use

setBootstrapCacheLoader

public void setBootstrapCacheLoader(BootstrapCacheLoader bootstrapCacheLoader)
                             throws CacheException

Sets the bootstrap cache loader.

Specified by:: setBootstrapCacheLoader in interface Ehcache

Parameters:: bootstrapCacheLoader - the loader to be used
Throws:: CacheException - if this method is called after the cache is initialized

setDiskStorePath

public void setDiskStorePath(java.lang.String diskStorePath)
                      throws CacheException

DiskStore paths can conflict between CacheManager instances. This method allows the path to be changed.

Specified by:: setDiskStorePath in interface Ehcache

Parameters:: diskStorePath - the new path to be used.
Throws:: CacheException - if this method is called after the cache is initialized

equals

public boolean equals(java.lang.Object object)

An equals method which follows the contract of Object.equals(Object)

An Cache is equal to another one if it implements Ehcache and has the same GUID.

Overrides:: equals in class java.lang.Object

Parameters:: object - the reference object with which to compare.
Returns:: true if this object is the same as the obj argument; false otherwise.
See Also:: hashCode(), Hashtable

hashCode

public int hashCode()

Returns a hash code value for the object. This method is supported for the benefit of hashtables such as those provided by java.util.Hashtable.

The general contract of hashCode is:

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the Object.equals(Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hashtables.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java^TM programming language.)

This implementation use the GUID of the cache.

Overrides:: hashCode in class java.lang.Object

Returns:: a hash code value for this object.
See Also:: Object.equals(Object), Hashtable

registerCacheExtension

public void registerCacheExtension(CacheExtension cacheExtension)

If the CacheExtension is not initialised, initialise it.

Specified by:: registerCacheExtension in interface Ehcache

unregisterCacheExtension

public void unregisterCacheExtension(CacheExtension cacheExtension)

Unregister a CacheExtension with the cache. It will then be detached from the cache lifecycle.

Specified by:: unregisterCacheExtension in interface Ehcache

getAverageGetTime

public float getAverageGetTime()

The average get time in ms.

Specified by:: getAverageGetTime in interface Ehcache

setCacheExceptionHandler

public void setCacheExceptionHandler(CacheExceptionHandler cacheExceptionHandler)

Sets an ExceptionHandler on the Cache. If one is already set, it is overwritten.

The ExceptionHandler is only used if this Cache's methods are accessed using ExceptionHandlingDynamicCacheProxy.

Specified by:: setCacheExceptionHandler in interface Ehcache

See Also:: ExceptionHandlingDynamicCacheProxy

getCacheExceptionHandler

public CacheExceptionHandler getCacheExceptionHandler()

Gets the ExceptionHandler on this Cache, or null if there isn't one.

The ExceptionHandler is only used if this Cache's methods are accessed using ExceptionHandlingDynamicCacheProxy.

Specified by:: getCacheExceptionHandler in interface Ehcache

See Also:: ExceptionHandlingDynamicCacheProxy

setCacheLoader

public void setCacheLoader(CacheLoader cacheLoader)

Setter for the CacheLoader. Changing the CacheLoader takes immediate effect.

Specified by:: setCacheLoader in interface Ehcache

Parameters:: cacheLoader - the loader to dynamically load new cache entries

getCacheLoader

public CacheLoader getCacheLoader()

Gets the CacheLoader registered in this cache

Specified by:: getCacheLoader in interface Ehcache

Returns:: the loader, or null if there is none

asynchronousLoad

edu.emory.mathcs.backport.java.util.concurrent.Future asynchronousLoad(java.lang.Object key,
                                                                       CacheLoader specificLoader,
                                                                       java.lang.Object argument)

Does the asynchronous loading.

Parameters:: specificLoader - a specific loader to use. If null the default loader is used.
Returns:: a Future which can be used to monitor execution

asynchronousLoadAll

edu.emory.mathcs.backport.java.util.concurrent.Future asynchronousLoadAll(java.util.Collection keys,
                                                                          java.lang.Object argument)

Does the asynchronous loading.

Parameters:: argument - the loader argument
Returns:: a Future which can be used to monitor execution

getExecutorService

edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor getExecutorService()

Returns:: Gets the executor service. This is not publically accessible.

isDisabled

public boolean isDisabled()

Whether this cache is disabled. "Disabled" means:

bootstrap is disabled
puts are discarded
putQuites are discarded

In all other respects the cache continues as it is.

You can disable and enable a cache programmatically through the setDisabled(boolean) method.

By default caches are enabled on creation, unless the net.sf.ehcache.disabled system property is set.

Specified by:: isDisabled in interface Ehcache

Returns:: true if the cache is disabled.
See Also:: ?

setDisabled

public void setDisabled(boolean disabled)

Disables or enables this cache. This call overrides the previous value of disabled, even if the net.sf.ehcache.disabled system property is set

Specified by:: setDisabled in interface Ehcache

Parameters:: disabled - true if you wish to disable, false to enable
See Also:: isDisabled()

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