com.jcorporate.expresso.core.cache
Interface Cache

All Known Implementing Classes:

OrderedCache, UnOrderedCache

public interface Cache

A cache is a list of Cacheable objects that can be stored in memory, cleared, added to and removed from. It also stores information about how many times it has been used. This interface defines how a generic cache object should behave, but the specifics are up to the implementor.

Implementation Note: The implementation of ordered or unordered caches should be such that getItems() or getItem() will NEVER return an expired cache item. Implementations should check isExpired() before adding the cache item to the return list.

Method Summary

void	addItem(CacheEntry newItem) Add a new item to the cache.
void	clear() Clear all items from the cache
CacheEntry	getCacheEntry(String itemKey) Retrieve the low-level CacheEntry for the cache.
Cacheable	getItem(String itemKey) Get the item indicated by the given key from the cache.
int	getItemCount() Retrieve Cache Item Count
Vector	getItems() Get all the items in the cache
String	getName() Get the name of the cache
long	getUsedCount() Get how many times this cache has been used
boolean	isOrdered() Retrieve whether the cache instance is an ordered cache [list based] or unordered cache.
void	removeItem(Cacheable itemKey) Removes the specified item from the cache.
void	setItems(List newItems) Eventually the new way to set items
void	setItems(Vector newItems) Set the items in the cache
void	setMaxSize(int newMax) Sets the maximum size of the cache
void	setName(String newName) Sets the name of the cache

Method Detail

addItem

public void addItem(CacheEntry newItem)

Add a new item to the cache.

Parameters:

newItem - the new item to add to the cache

clear

public void clear()

Clear all items from the cache

getCacheEntry

public CacheEntry getCacheEntry(String itemKey)

Retrieve the low-level CacheEntry for the cache. This is particularly useful for debugging or management.

Parameters:

itemKey - the key for the entry

Returns:

a CacheEntry object or null if it doesn't exist

getItem

public Cacheable getItem(String itemKey)

Get the item indicated by the given key from the cache. All Cacheable items define a getKey() method that defines how the item is differentated from other items in the cache

Parameters:

itemKey - the key of the item to retrieve

Returns:

the Object stored in the cache.

isOrdered

public boolean isOrdered()

Retrieve whether the cache instance is an ordered cache [list based] or unordered cache. [map based]

Returns:

true if the cache is an ordered cache.

getItemCount

public int getItemCount()

Retrieve Cache Item Count

Returns:

The number of items in the cache

getItems

public Vector getItems()

Get all the items in the cache

Returns:

java.util.Vector - The items in the cache

getName

public String getName()

Get the name of the cache

Returns:

java.lang.String the name of the cache.

getUsedCount

public long getUsedCount()

Get how many times this cache has been used

Returns:

long

removeItem

public void removeItem(Cacheable itemKey)

Removes the specified item from the cache.

Parameters:

itemKey - The item in the cache to remove

setItems

public void setItems(Vector newItems)
              throws CacheException

Set the items in the cache

Parameters:

newItems - The vector of new items

Throws:

CacheException - If there's an error setting the new items in the cache

setItems

public void setItems(List newItems)
              throws CacheException

Eventually the new way to set items

Parameters:

newItems - the new items to add

Throws:

CacheException - upon error

setMaxSize

public void setMaxSize(int newMax)

Sets the maximum size of the cache

Parameters:

newMax - The new maximum size of the cache.

setName

public void setName(String newName)

Sets the name of the cache

Parameters:

newName - java.lang.String The new name of the cache.