freemarker.template.cache
Class LoadOnDemandCachingStrategy

java.lang.Object
  freemarker.template.cache.BaseCachingStrategy
      freemarker.template.cache.LoadOnDemandCachingStrategy

All Implemented Interfaces:

Cache, CachingStrategy, Updateable

public final class LoadOnDemandCachingStrategy
extends BaseCachingStrategy

Implements a load-on-demand caching strategy.

Version:

$Id: LoadOnDemandCachingStrategy.java 1153 2013-04-15 10:59:37Z run2000 $

Author:

Nicholas Cull

Field Summary

Fields inherited from class freemarker.template.cache.BaseCachingStrategy

eventHandler, retriever

Constructor Summary

LoadOnDemandCachingStrategy()
Creates new LoadOnDemandCachingStrategy.

LoadOnDemandCachingStrategy(StrategyParameters params)
Creates new LoadOnDemandCachingStrategy with the given parameters.

Method Summary

void	clearCache() Clears all the elements in the cache.
java.lang.String	getDefaultTemplateType() Retrieves the default template type to be created when retrieving items from the cache.
long	getDelay() Returns the interval between two cache updates.
Cacheable	getItem(java.lang.String name) Retrieves an item from the cache, according to the loading policy implemented.
Cacheable	getItem(java.lang.String name, java.lang.String type) Retrieves an item from the cache, according to the loading policy implemented.
int	getMaximumAge() Retrieves the maximum age a cache item can be before it is evicted from the cache.
java.util.Iterator<CacheElement>	listCachedFiles() Retrieves a list of objects currently in the cache.
void	startAutoUpdate() Begins automatic updates of the cache.
void	stopAutoUpdate() Stops automatically updating the cache.
java.lang.String	toString() Returns a string representation of the object.
void	update() Asks for a "blank" update.
void	update(java.lang.String name) Asks for the named object to be updated.
void	update(java.lang.String name, java.lang.String type) Asks for the named object to be updated.

Methods inherited from class freemarker.template.cache.BaseCachingStrategy

addCacheListener, connectionOk, getCacheListeners, getCacheRetriever, removeCacheListener

Methods inherited from class java.lang.Object

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

Constructor Detail

LoadOnDemandCachingStrategy

public LoadOnDemandCachingStrategy()

Creates new LoadOnDemandCachingStrategy.

LoadOnDemandCachingStrategy

public LoadOnDemandCachingStrategy(StrategyParameters params)

Creates new LoadOnDemandCachingStrategy with the given parameters.

Parameters:

params - the parameters with which to initialize this strategy

Method Detail

getDelay

public long getDelay()

Returns the interval between two cache updates. This is meaningful only if the cache policy is a load-on-demand or preload type.

Returns:

the number of seconds between cache updates

getMaximumAge

public int getMaximumAge()

Retrieves the maximum age a cache item can be before it is evicted from the cache. The age is determined as the number of cache updates since the item was last accessed. This is meaningful only if the cache policy is a load-on-demand type.

Returns:

the maximum age before an item is evicted from the cache

getDefaultTemplateType

public java.lang.String getDefaultTemplateType()

Retrieves the default template type to be created when retrieving items from the cache.

Returns:

the type of template cached by default

getItem

public Cacheable getItem(java.lang.String name)

Retrieves an item from the cache, according to the loading policy implemented.

Parameters:

name - the name of the item to retrieve

Returns:

the corresponding Cacheable object, or null if not found or an error has occurred

getItem

public Cacheable getItem(java.lang.String name,
                         java.lang.String type)

Retrieves an item from the cache, according to the loading policy implemented.

Parameters:

name - the name of the item to retrieve

type - the type of item to be retrieved

Returns:

the corresponding Cacheable object, or null if not found or an error has occurred

listCachedFiles

public java.util.Iterator<CacheElement> listCachedFiles()

Retrieves a list of objects currently in the cache.

Returns:

an iterator that can recurse over the cached objects. May return null if there are no items in the cache, or the strategy does not implement a cache.

update

public void update()
            throws java.lang.InterruptedException

Asks for a "blank" update. It is up to the implementation to determine what has to be updated.

Throws:

java.lang.InterruptedException - The current thread was interrupted during the update. Callers should either throw the exception back up the call stack, or set the interrupted status by using the Thread.currentThread().interrupt() method.

update

public void update(java.lang.String name)

Asks for the named object to be updated.

Parameters:

name - the name of the object to update

update

public void update(java.lang.String name,
                   java.lang.String type)

Asks for the named object to be updated.

Parameters:

name - the name of the object to update

type - the type of the object to update

stopAutoUpdate

public void stopAutoUpdate()

Stops automatically updating the cache.

startAutoUpdate

public void startAutoUpdate()

Begins automatic updates of the cache.

clearCache

public void clearCache()

Clears all the elements in the cache.

toString

public java.lang.String toString()

Returns a string representation of the object.

Overrides:

toString in class java.lang.Object

Returns:

a String representation of the object