helma.util
Class CacheMap

java.lang.Object
  helma.util.CacheMap

All Implemented Interfaces:

ObjectCache

Direct Known Subclasses:

WeakCacheMap

public class CacheMap
extends java.lang.Object
implements ObjectCache

Constructor Summary

CacheMap()
Zero argument constructor.

CacheMap(int initialCapacity)

CacheMap(int initialCapacity, float loadFactor)

Method Summary

boolean	clear() Removes all items currently stored in the cache.
boolean	containsKey(java.lang.Object key) Returns true if the collection contains an element for the key.
int	containsKeys(java.lang.Object[] keys) Returns the number of keys in object array keys that were not found in the Map.
boolean	containsValue(java.lang.Object value)
protected java.util.Map	createTable(int capacity, float loadFactor) Override this method to use custom Map implementations.
java.lang.Object	get(java.lang.Object key) Gets the object associated with the specified key in the hashtable.
java.lang.Object[]	getCachedObjects() Return an array with all objects currently contained in the cache.
void	init(Application app) Set the Application instance for the cache.
boolean	isEmpty()
java.lang.Object	put(java.lang.Object key, java.lang.Object value) Puts the specified element into the hashtable, using the specified key.
java.lang.Object	remove(java.lang.Object key) Removes the element corresponding to the key.
void	setCapacity(int capacity)
void	shutdown() Called when the application holding the cache is stopped.
int	size() Return the number of objects currently stored in the cache.
java.lang.String	toString()
void	updateProperties(java.util.Properties props) Called when the application's properties have been updated to let the cache implementation update its settings.

Methods inherited from class java.lang.Object

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

Constructor Detail

CacheMap

public CacheMap()

Zero argument constructor. Creates a CacheMap with capacity of 1000 and load factor 0.75

CacheMap

public CacheMap(int initialCapacity,
                float loadFactor)

CacheMap

public CacheMap(int initialCapacity)

Method Detail

size

public int size()

Description copied from interface: ObjectCache

Return the number of objects currently stored in the cache.

Specified by:

size in interface ObjectCache

Returns:

the number of cached items

isEmpty

public boolean isEmpty()

setCapacity

public void setCapacity(int capacity)

containsValue

public boolean containsValue(java.lang.Object value)

containsKey

public boolean containsKey(java.lang.Object key)

Description copied from interface: ObjectCache

Returns true if the collection contains an element for the key.

Specified by:

containsKey in interface ObjectCache

Parameters:

key - the key that we are looking for

containsKeys

public int containsKeys(java.lang.Object[] keys)

Description copied from interface: ObjectCache

Returns the number of keys in object array keys that were not found in the Map. Those keys that are contained in the Map are nulled out in the array.

Specified by:

containsKeys in interface ObjectCache

Parameters:

keys - an array of key objects we are looking for

See Also:

ObjectCache.containsKey(java.lang.Object)

get

public java.lang.Object get(java.lang.Object key)

Description copied from interface: ObjectCache

Gets the object associated with the specified key in the hashtable.

Specified by:

get in interface ObjectCache

Parameters:

key - the specified key

Returns:

the element for the key or null if the key is not defined in the hash table.

See Also:

ObjectCache.put(java.lang.Object, java.lang.Object)

put

public java.lang.Object put(java.lang.Object key,
                            java.lang.Object value)

Description copied from interface: ObjectCache

Puts the specified element into the hashtable, using the specified key. The element may be retrieved by doing a get() with the same key. The key and the element cannot be null.

Specified by:

put in interface ObjectCache

Parameters:

key - the specified key in the hashtable

value - the specified element

Returns:

the old value of the key, or null if it did not have one.

See Also:

ObjectCache.get(java.lang.Object)

remove

public java.lang.Object remove(java.lang.Object key)

Description copied from interface: ObjectCache

Removes the element corresponding to the key. Does nothing if the key is not present.

Specified by:

remove in interface ObjectCache

Parameters:

key - the key that needs to be removed

Returns:

the value of key, or null if the key was not found.

clear

public boolean clear()

Description copied from interface: ObjectCache

Removes all items currently stored in the cache.

Specified by:

clear in interface ObjectCache

Returns:

true if the operation succeeded

shutdown

public void shutdown()

Description copied from interface: ObjectCache

Called when the application holding the cache is stopped.

Specified by:

shutdown in interface ObjectCache

init

public void init(Application app)

Description copied from interface: ObjectCache

Set the Application instance for the cache.

Specified by:

init in interface ObjectCache

Parameters:

app - the app instance

updateProperties

public void updateProperties(java.util.Properties props)

Description copied from interface: ObjectCache

Called when the application's properties have been updated to let the cache implementation update its settings.

Specified by:

updateProperties in interface ObjectCache

getCachedObjects

public java.lang.Object[] getCachedObjects()

Description copied from interface: ObjectCache

Return an array with all objects currently contained in the cache.

Specified by:

getCachedObjects in interface ObjectCache

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

createTable

protected java.util.Map createTable(int capacity,
                                    float loadFactor)

Override this method to use custom Map implementations. The default implementation returns a java.util.HashMap instance.

Parameters:

capacity - the initial capacity

loadFactor - the load factor

Returns:

a new Map used for internal caching