org.exolab.castor.persist
Class LRU.CountLimited

java.lang.Object
  org.exolab.castor.persist.LRU
      org.exolab.castor.persist.LRU.CountLimited

Enclosing class:

LRU

public static class LRU.CountLimited

extends LRU

CountLimited is a count limted least-recently-used Map.

Every object being put in the Map will live until the map is full. If the map is full, a least-recently-used object will be disposed.

Method dispose(Object) will be called whenever an old object is diposed. Developer can get notify by overriding the dispose method dispose(Object).

Author:

Thomas Yip

Nested Class Summary

Nested classes inherited from class org.exolab.castor.persist.LRU

LRU.CountLimited, LRU.NoCache, LRU.TimeLimited, LRU.Unlimited

Field Summary

Fields inherited from class org.exolab.castor.persist.LRU

CACHE_COUNT_LIMITED, CACHE_NONE, CACHE_TIME_LIMITED, CACHE_UNLIMITED, DEFAULT_PARAM, DEFAULT_TYPE

Constructor Summary

LRU.CountLimited(int size)

Method Summary

protected void	dispose(java.lang.Object o) This method is called when an object is disposed.
java.util.Enumeration	elements() Returns an enumeration of the values in this LRU map.
java.lang.Object	get(java.lang.Object key) Returns the value to which the specified key is mapped in this Map.
java.lang.Object	put(java.lang.Object key, java.lang.Object object) Maps the specified key to the specified value in this Map.
java.lang.Object	remove(java.lang.Object key) Removes the key (and its corresponding value) from this Map.

Methods inherited from class org.exolab.castor.persist.LRU

create, mapType

Methods inherited from class java.lang.Object

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

Constructor Detail

LRU.CountLimited

public LRU.CountLimited(int size)

Method Detail

put

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

Maps the specified key to the specified value in this Map. 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 when the Map is full.

Specified by:

put in class LRU

Parameters:

key - the Map key.

object - the value.

Returns:

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

Throws:

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

get

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

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

Specified by:

get in class LRU

Parameters:

key - - a key in the Map.

Returns:

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

remove

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

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

Specified by:

remove in class LRU

Parameters:

key - the key that needs to be removed.

Returns:

the value to which the key had been mapped in this Map, 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.

Specified by:

elements in class LRU

Returns:

an enumeration of the values in this Map.

See Also:

Enumeration

dispose

protected void dispose(java.lang.Object o)

This method is called when an object is disposed. Override this method if you interested in the disposed object.

Parameters:

o - - the disposed object