wt.epm.util
Class EPMCache.ObjectCache

java.lang.Object
  wt.epm.util.EPMCache.ObjectCache

Enclosing class:

EPMCache

public static class EPMCache.ObjectCache

extends Object

An Object Cache holds Persistable objects and indexes them by their object identifiers. Given an object identifier, it returns the object with that identifier. If an object is not in its cache, the Object Cache will query it from the database and add it to its cache.

Field Summary

private HashMap

cache

Constructor Summary

EPMCache.ObjectCache()
Constructs an ObjectCache.

EPMCache.ObjectCache(Collection objects)
Constructs an ObjectCache adding the collection of Persistable objects to its cache.

Method Summary

void	add(Collection objects) Adds a collection of Persistable objects to the Object Cache.
void	add(Persistable object) Adds a Persistable object to the Object Cache.
boolean	contains(ObjectIdentifier objectId) Returns true if the cache contains the Persistable object with the given object identifier.
boolean	contains(Persistable object) Returns true if the cache contains the given Persistable object.
List	find(Collection objectIds) Given a collection of object identifiers, returns the Persistable objects with these identifiers.
Persistable	get(ObjectIdentifier objectId) Given an object identifier, returns the object with that identifier provided it is in the cache.
boolean	isEmpty() Returns true if the cache contains no objects.
Collection	objects() Returns an unmodifiable collection view of the objects in this cache.

Methods inherited from class java.lang.Object

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

Field Detail

cache

private HashMap cache

Constructor Detail

EPMCache.ObjectCache

public EPMCache.ObjectCache()

Constructs an ObjectCache.

EPMCache.ObjectCache

public EPMCache.ObjectCache(Collection objects)

Constructs an ObjectCache adding the collection of Persistable objects to its cache.

Method Detail

get

public Persistable get(ObjectIdentifier objectId)

Given an object identifier, returns the object with that identifier provided it is in the cache. If it is not, this method returns null.

add

public void add(Persistable object)

Adds a Persistable object to the Object Cache.

add

public void add(Collection objects)

Adds a collection of Persistable objects to the Object Cache.

find

public List find(Collection objectIds)
          throws WTException

Given a collection of object identifiers, returns the Persistable objects with these identifiers. If an object is not in its cache, the Object Cache will query it from the database and add it to its cache.

Throws:

WTException

objects

public Collection objects()

Returns an unmodifiable collection view of the objects in this cache.

isEmpty

public boolean isEmpty()

Returns true if the cache contains no objects.

contains

public boolean contains(Persistable object)

Returns true if the cache contains the given Persistable object.

contains

public boolean contains(ObjectIdentifier objectId)

Returns true if the cache contains the Persistable object with the given object identifier.