org.exolab.castor.persist.cache
Interface Cache

All Known Implementing Classes:

AbstractBaseCache, CountLimited, NoCache, TimeLimited

public interface Cache

Interface specification for performance caches as used in Castor. Please implement this interface if you wish to provide your own cache implementation.

Version:

$Revision: 1.5 $ $Date: 2005/08/04 07:31:15 $

Author:

Werner Guttmann

Method Summary

void	clear() Removes all mappings from this map.
void	close() Life-cycle method to allow custom resource cleanup for a cache implementation
boolean	contains(java.lang.Object key) Indicates whether the cache holds value object mapped to the specified key.
boolean	containsKey(java.lang.Object key) Returns true if this map contains a mapping for the specified key
boolean	containsValue(java.lang.Object value) Returns true if this map maps one or more keys to the specified value.
java.util.Enumeration	elements() Returns an enumeration of the values in this LRU map.
java.util.Set	entrySet() Returns a set view of the keys contained in this map.
void	expire(java.lang.Object key) Remove the object identified by key from the cache.
java.lang.Object	get(java.lang.Object key) Returns the value to which the specified key is mapped in this hashtable.
java.lang.String	getCacheType() Indicates the type of this cache.
int	getCapacity() Indicates the cache capacity.
java.lang.String	getClassName() Indicates the class name of objects stored in this cache.
void	initialize() Lyfe-cycle method to allow custom initialization of cache implementations
boolean	isEmpty() Returns true if this map contains no key-value mappings.
java.util.Set	keySet() Returns a collection view of the values contained in this map.
java.lang.Object	put(java.lang.Object key, java.lang.Object value) Maps the specified key to the specified value in this hashtable.
void	putAll(java.util.Map aMap) Copies all of the mappings from the specified map to this map (optional operation).
java.lang.Object	remove(java.lang.Object key) Removes the key (and its corresponding value) from this hashtable.
void	setCacheType(java.lang.String cacheType) Sets the type of this cache instance.
void	setCapacity(int capacity) Sets the cache capacity.
void	setClassName(java.lang.String className) Sets the class name of objects cached here.
int	size() Returns the number of key-value mappings in this map.
java.util.Collection	values()

Method Detail

initialize

public void initialize()
                throws CacheAcquireException

Lyfe-cycle method to allow custom initialization of cache implementations

Throws:

CacheAcquireException

close

public void close()

Life-cycle method to allow custom resource cleanup for a cache implementation

get

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

Returns the value to which the specified key is mapped in this hashtable.

Parameters:

key - - a key in the hashtable.

Returns:

the value to which the key is mapped in this hashtable; null if the key is not mapped to any value in this hashtable.

put

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

Maps the specified key to the specified value in this hashtable. Neither the key nor the value can be null.

The value can be retrieved by calling the get method with a key that is equal to the original key, before it is diposed by the least-recently-used map.

Parameters:

key - the hashtable key.

value - the value.

Returns:

the previous value of the specified key in this hashtable, or null if it did not have one.

Throws:

java.lang.NullPointerException - if the key or value is null.

remove

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

Removes the key (and its corresponding value) from this hashtable. This method does nothing if the key is not in the hashtable.

Parameters:

key - the key that needs to be removed.

Returns:

the value to which the key had been mapped in this hashtable, or null if the key did not have a mapping.

elements

public java.util.Enumeration elements()

Returns an enumeration of the values in this LRU map. Use the Enumeration methods on the returned object to fetch the elements sequentially.

Returns:

an enumeration of the values in this hashtable.

See Also:

Enumeration

expire

public void expire(java.lang.Object key)

Remove the object identified by key from the cache.

Parameters:

key - the key that needs to be removed.

contains

public boolean contains(java.lang.Object key)

Indicates whether the cache holds value object mapped to the specified key.

Parameters:

key - A key identifying a value object.

Returns:

True if the cache holds a value object for the specified key, false otherwise.

getCacheType

public java.lang.String getCacheType()

Indicates the type of this cache.

Returns:

the cache type.

setCacheType

public void setCacheType(java.lang.String cacheType)

Sets the type of this cache instance.

Parameters:

cacheType - The type of this cache.

getCapacity

public int getCapacity()

Indicates the cache capacity.

Returns:

the cache capacity.

setCapacity

public void setCapacity(int capacity)

Sets the cache capacity.

Parameters:

capacity - the cache capacity.

getClassName

public java.lang.String getClassName()

Indicates the class name of objects stored in this cache.

Returns:

The class name.

setClassName

public void setClassName(java.lang.String className)

Sets the class name of objects cached here.

Parameters:

className - The class name.

size

public int size()
         throws MethodNotImplementedException

Returns the number of key-value mappings in this map.

Throws:

MethodNotImplementedException

clear

public void clear()
           throws MethodNotImplementedException

Removes all mappings from this map.

Throws:

MethodNotImplementedException

isEmpty

public boolean isEmpty()
                throws MethodNotImplementedException

Returns true if this map contains no key-value mappings.

Returns:

True if this map contains no key-value mappings

Throws:

MethodNotImplementedException

containsKey

public boolean containsKey(java.lang.Object key)
                    throws MethodNotImplementedException

Returns true if this map contains a mapping for the specified key

Parameters:

key - A key object.

Returns:

true if this map contains a mapping for the specified key

Throws:

MethodNotImplementedException

containsValue

public boolean containsValue(java.lang.Object value)
                      throws MethodNotImplementedException

Returns true if this map maps one or more keys to the specified value. This operation will probably require time linear to the cache size for most implementations of the Cache interface.

Parameters:

value - The object value.

Returns:

true if this map maps one or more keys to the specified value

Throws:

MethodNotImplementedException

values

public java.util.Collection values()
                            throws MethodNotImplementedException

Returns:

Throws:

MethodNotImplementedException

putAll

public void putAll(java.util.Map aMap)

Copies all of the mappings from the specified map to this map (optional operation).

Parameters:

aMap - The map to be copied.

entrySet

public java.util.Set entrySet()
                       throws MethodNotImplementedException

Returns a set view of the keys contained in this map.

Returns:

A set view of all the keys.

Throws:

MethodNotImplementedException

keySet

public java.util.Set keySet()
                     throws MethodNotImplementedException

Returns a collection view of the values contained in this map.

Returns:

A set view of all the value objects.

Throws:

MethodNotImplementedException