com.opensymphony.oscache.web
Class ServletCache

java.lang.Object
  com.opensymphony.oscache.base.Cache
      com.opensymphony.oscache.web.ServletCache

All Implemented Interfaces:

Serializable, EventListener, javax.servlet.http.HttpSessionBindingListener

public final class ServletCache
extends Cache
implements javax.servlet.http.HttpSessionBindingListener, Serializable

A simple extension of Cache that implements a session binding listener, and deletes it's entries when unbound

Version:

$Revision: 339 $

Author:

Mike Cannon-Brookes, Todd Gochenour, Francois Beauregard

See Also:

Serialized Form

Field Summary

private ServletCacheAdministrator	admin The admin for this cache
private static Log	log
private int	scope The scope of that cache.

Fields inherited from class com.opensymphony.oscache.base.Cache

listenerList, NESTED_EVENT

Constructor Summary

ServletCache(ServletCacheAdministrator admin, int scope)
Create a new ServletCache

ServletCache(ServletCacheAdministrator admin, String algorithmClass, int limit, int scope)
Create a new Cache

Method Summary

int	getScope() Get the cache scope
protected boolean	isStale(CacheEntry cacheEntry, int refreshPeriod, String cronExpiry) Indicates whether or not the cache entry is stale.
private void	setScope(int scope)
void	valueBound(javax.servlet.http.HttpSessionBindingEvent event) When this Cache is bound to the session, do nothing.
void	valueUnbound(javax.servlet.http.HttpSessionBindingEvent event) When the users's session ends, all listeners are finalized and the session cache directory is deleted from disk.

Methods inherited from class com.opensymphony.oscache.base.Cache

addCacheEventListener, addCacheEventListener, cancelUpdate, clear, completeUpdate, flushAll, flushAll, flushEntry, flushEntry, flushGroup, flushGroup, flushPattern, flushPattern, getCacheEntry, getCacheEventListenerList, getCapacity, getFromCache, getFromCache, getFromCache, getNbEntries, getNbUpdateState, getPersistenceListener, getSize, getUpdateState, isFlushed, putInCache, putInCache, putInCache, putInCache, releaseUpdateState, removeCacheEventListener, removeCacheEventListener, removeEntry, removeEntry, setCapacity, setPersistenceListener

Methods inherited from class java.lang.Object

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

Field Detail

log

private static final transient Log log

admin

private ServletCacheAdministrator admin

The admin for this cache

scope

private int scope

The scope of that cache.

Constructor Detail

ServletCache

public ServletCache(ServletCacheAdministrator admin,
                    int scope)

Create a new ServletCache

Parameters:

admin - The ServletCacheAdministrator to administer this ServletCache.

scope - The scope of all entries in this hashmap

ServletCache

public ServletCache(ServletCacheAdministrator admin,
                    String algorithmClass,
                    int limit,
                    int scope)

Create a new Cache

Parameters:

admin - The CacheAdministrator to administer this Cache.

algorithmClass - The class that implement an algorithm

limit - The maximum cache size in number of entries

scope - The cache scope

Method Detail

getScope

public int getScope()

Get the cache scope

Returns:

The cache scope

setScope

private void setScope(int scope)

valueBound

public void valueBound(javax.servlet.http.HttpSessionBindingEvent event)

When this Cache is bound to the session, do nothing.

Specified by:

valueBound in interface javax.servlet.http.HttpSessionBindingListener

Parameters:

event - The SessionBindingEvent.

valueUnbound

public void valueUnbound(javax.servlet.http.HttpSessionBindingEvent event)

When the users's session ends, all listeners are finalized and the session cache directory is deleted from disk.

Specified by:

valueUnbound in interface javax.servlet.http.HttpSessionBindingListener

Parameters:

event - The event that triggered this unbinding.

isStale

protected boolean isStale(CacheEntry cacheEntry,
                          int refreshPeriod,
                          String cronExpiry)

Indicates whether or not the cache entry is stale. This overrides the Cache.isStale(CacheEntry, int, String) method to take into account any flushing that may have been applied to the scope that this cache belongs to.

Overrides:

isStale in class Cache

Parameters:

cacheEntry - The cache entry to test the freshness of.

refreshPeriod - The maximum allowable age of the entry, in seconds.

cronExpiry - A cron expression that defines fixed expiry dates and/or times for this cache entry.

Returns:

true if the entry is stale, false otherwise.