The Spring Framework

org.springframework.cache.ehcache
Class EhCacheFactoryBean

java.lang.Object
  extended by org.springframework.cache.ehcache.EhCacheFactoryBean
All Implemented Interfaces:
BeanNameAware, FactoryBean, InitializingBean

public class EhCacheFactoryBean
extends Object
implements FactoryBean, BeanNameAware, InitializingBean

FactoryBean that creates a named EHCache Cache instance (or a decorator that implements the Ehcache interface), representing a cache region within an EHCache CacheManager.

If the specified named cache is not configured in the cache configuration descriptor, this FactoryBean will construct an instance of a Cache with the provided name and the specified cache properties and add it to the CacheManager for later retrieval. If some or all properties are not set at configuration time, this FactoryBean will use defaults.

Note: If the named Cache instance is found, the properties will be ignored and the Cache instance will be retrieved from the CacheManager.

Note: As of Spring 2.0, this FactoryBean is based on EHCache 1.2's API (in particular the Ehcache interface and the extended Cache constructor). It is not compatible with EHCache 1.1 anymore; please upgrade to EHCache 1.2.4 or higher.

Since:
1.1.1
Author:
Dmitriy Kopylenko, Juergen Hoeller
See Also:
setCacheManager(net.sf.ehcache.CacheManager), EhCacheManagerFactoryBean, Cache

Field Summary
protected  Log logger
           
 
Constructor Summary
EhCacheFactoryBean()
           
 
Method Summary
 void afterPropertiesSet()
          Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
protected  Ehcache decorateCache(Cache cache)
          Decorate the given Cache, if necessary.
 Object getObject()
          Return an instance (possibly shared or independent) of the object managed by this factory.
 Class getObjectType()
          Return the type of object that this FactoryBean creates, or null if not known in advance.
 boolean isSingleton()
          Is the object managed by this factory a singleton?
 void setBeanName(String name)
          Set the name of the bean in the bean factory that created this bean.
 void setBlocking(boolean blocking)
          Set whether to use a blocking cache that lets read attempts block until the requested element is created.
 void setCacheEntryFactory(CacheEntryFactory cacheEntryFactory)
          Set an EHCache CacheEntryFactory to use for a self-populating cache.
 void setCacheManager(CacheManager cacheManager)
          Set a CacheManager from which to retrieve a named Cache instance.
 void setCacheName(String cacheName)
          Set a name for which to retrieve or create a cache instance.
 void setDiskExpiryThreadIntervalSeconds(int diskExpiryThreadIntervalSeconds)
          Set the number of seconds between runs of the disk expiry thread.
 void setDiskPersistent(boolean diskPersistent)
          Set whether the disk store persists between restarts of the Virtual Machine.
 void setDiskStorePath(String diskStorePath)
          Set the location of temporary files for the disk store of this cache.
 void setEternal(boolean eternal)
          Set whether elements are considered as eternal.
 void setMaxElementsInMemory(int maxElementsInMemory)
          Specify the maximum number of cached objects in memory.
 void setMaxElementsOnDisk(int maxElementsOnDisk)
          Specify the maximum number of cached objects on disk.
 void setMemoryStoreEvictionPolicy(MemoryStoreEvictionPolicy memoryStoreEvictionPolicy)
          Set the memory style eviction policy for this cache.
 void setOverflowToDisk(boolean overflowToDisk)
          Set whether elements can overflow to disk when the in-memory cache has reached the maximum size limit.
 void setTimeToIdle(int timeToIdle)
          Set the time in seconds to idle for an element before it expires, that is, the maximum amount of time between accesses before an element expires.
 void setTimeToLive(int timeToLive)
          Set t he time in seconds to live for an element before it expires, i.e. the maximum time between creation time and when an element expires.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

logger

protected final Log logger
Constructor Detail

EhCacheFactoryBean

public EhCacheFactoryBean()
Method Detail

setCacheManager

public void setCacheManager(CacheManager cacheManager)
Set a CacheManager from which to retrieve a named Cache instance. By default, CacheManager.getInstance() will be called.

Note that in particular for persistent caches, it is advisable to properly handle the shutdown of the CacheManager: Set up a separate EhCacheManagerFactoryBean and pass a reference to this bean property.

A separate EhCacheManagerFactoryBean is also necessary for loading EHCache configuration from a non-default config location.

See Also:
EhCacheManagerFactoryBean, CacheManager.getInstance()

setCacheName

public void setCacheName(String cacheName)
Set a name for which to retrieve or create a cache instance. Default is the bean name of this EhCacheFactoryBean.


setMaxElementsInMemory

public void setMaxElementsInMemory(int maxElementsInMemory)
Specify the maximum number of cached objects in memory. Default is 10000 elements.


setMaxElementsOnDisk

public void setMaxElementsOnDisk(int maxElementsOnDisk)
Specify the maximum number of cached objects on disk. Default is 10000000 elements.


setMemoryStoreEvictionPolicy

public void setMemoryStoreEvictionPolicy(MemoryStoreEvictionPolicy memoryStoreEvictionPolicy)
Set the memory style eviction policy for this cache. Supported values are "LRU", "LFU" and "FIFO", according to the constants defined in EHCache's MemoryStoreEvictionPolicy class. Default is "LRU".


setOverflowToDisk

public void setOverflowToDisk(boolean overflowToDisk)
Set whether elements can overflow to disk when the in-memory cache has reached the maximum size limit. Default is "true".


setDiskStorePath

public void setDiskStorePath(String diskStorePath)
Set the location of temporary files for the disk store of this cache. Default is the CacheManager's disk store path.


setEternal

public void setEternal(boolean eternal)
Set whether elements are considered as eternal. If "true", timeouts are ignored and the element is never expired. Default is "false".


setTimeToLive

public void setTimeToLive(int timeToLive)
Set t he time in seconds to live for an element before it expires, i.e. the maximum time between creation time and when an element expires. It is only used if the element is not eternal. Default is 120 seconds.


setTimeToIdle

public void setTimeToIdle(int timeToIdle)
Set the time in seconds to idle for an element before it expires, that is, the maximum amount of time between accesses before an element expires. This is only used if the element is not eternal. Default is 120 seconds.


setDiskPersistent

public void setDiskPersistent(boolean diskPersistent)
Set whether the disk store persists between restarts of the Virtual Machine. The default is "false".


setDiskExpiryThreadIntervalSeconds

public void setDiskExpiryThreadIntervalSeconds(int diskExpiryThreadIntervalSeconds)
Set the number of seconds between runs of the disk expiry thread. The default is 120 seconds.


setBlocking

public void setBlocking(boolean blocking)
Set whether to use a blocking cache that lets read attempts block until the requested element is created.

If you intend to build a self-populating blocking cache, consider specifying a CacheEntryFactory.

See Also:
BlockingCache, setCacheEntryFactory(net.sf.ehcache.constructs.blocking.CacheEntryFactory)

setCacheEntryFactory

public void setCacheEntryFactory(CacheEntryFactory cacheEntryFactory)
Set an EHCache CacheEntryFactory to use for a self-populating cache. If such a factory is specified, the cache will be decorated with EHCache's SelfPopulatingCache.

The specified factory can be of type UpdatingCacheEntryFactory, which will lead to the use of an UpdatingSelfPopulatingCache.

Note: Any such self-populating cache is automatically a blocking cache.

See Also:
SelfPopulatingCache, UpdatingSelfPopulatingCache, UpdatingCacheEntryFactory

setBeanName

public void setBeanName(String name)
Description copied from interface: BeanNameAware
Set the name of the bean in the bean factory that created this bean.

Invoked after population of normal bean properties but before an init callback such as InitializingBean.afterPropertiesSet() or a custom init-method.

Specified by:
setBeanName in interface BeanNameAware
Parameters:
name - the name of the bean in the factory. Note that this name is the actual bean name used in the factory, which may differ from the originally specified name: in particular for inner bean names, the actual bean name might have been made unique through appending "#..." suffixes. Use the BeanFactoryUtils.originalBeanName(String) method to extract the original bean name (without suffix), if desired.

afterPropertiesSet

public void afterPropertiesSet()
                        throws CacheException,
                               IOException
Description copied from interface: InitializingBean
Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).

This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.

Specified by:
afterPropertiesSet in interface InitializingBean
Throws:
CacheException
IOException

decorateCache

protected Ehcache decorateCache(Cache cache)
Decorate the given Cache, if necessary.

The default implementation simply returns the given cache object as-is.

Parameters:
cache - the raw Cache object, based on the configuration of this FactoryBean
Returns:
the (potentially decorated) cache object to be registered with the CacheManager

getObject

public Object getObject()
Description copied from interface: FactoryBean
Return an instance (possibly shared or independent) of the object managed by this factory.

As with a BeanFactory, this allows support for both the Singleton and Prototype design pattern.

If this FactoryBean is not fully initialized yet at the time of the call (for example because it is involved in a circular reference), throw a corresponding FactoryBeanNotInitializedException.

As of Spring 2.0, FactoryBeans are allowed to return null objects. The factory will consider this as normal value to be used; it will not throw a FactoryBeanNotInitializedException in this case anymore. FactoryBean implementations are encouraged to throw FactoryBeanNotInitializedException themselves now, as appropriate.

Specified by:
getObject in interface FactoryBean
Returns:
an instance of the bean (can be null)
See Also:
FactoryBeanNotInitializedException

getObjectType

public Class getObjectType()
Description copied from interface: FactoryBean
Return the type of object that this FactoryBean creates, or null if not known in advance.

This allows one to check for specific types of beans without instantiating objects, for example on autowiring.

In the case of implementations that are creating a singleton object, this method should try to avoid singleton creation as far as possible; it should rather estimate the type in advance. For prototypes, returning a meaningful type here is advisable too.

This method can be called before this FactoryBean has been fully initialized. It must not rely on state created during initialization; of course, it can still use such state if available.

NOTE: Autowiring will simply ignore FactoryBeans that return null here. Therefore it is highly recommended to implement this method properly, using the current state of the FactoryBean.

Specified by:
getObjectType in interface FactoryBean
Returns:
the type of object that this FactoryBean creates, or null if not known at the time of the call
See Also:
ListableBeanFactory.getBeansOfType(java.lang.Class)

isSingleton

public boolean isSingleton()
Description copied from interface: FactoryBean
Is the object managed by this factory a singleton? That is, will FactoryBean.getObject() always return the same object (a reference that can be cached)?

NOTE: If a FactoryBean indicates to hold a singleton object, the object returned from getObject() might get cached by the owning BeanFactory. Hence, do not return true unless the FactoryBean always exposes the same reference.

The singleton status of the FactoryBean itself will generally be provided by the owning BeanFactory; usually, it has to be defined as singleton there.

NOTE: This method returning false does not necessarily indicate that returned objects are independent instances. An implementation of the extended SmartFactoryBean interface may explicitly indicate independent instances through its SmartFactoryBean.isPrototype() method. Plain FactoryBean implementations which do not implement this extended interface are simply assumed to always return independent instances if the isSingleton() implementation returns false.

Specified by:
isSingleton in interface FactoryBean
Returns:
whether the exposed object is a singleton
See Also:
FactoryBean.getObject(), SmartFactoryBean.isPrototype()

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