de.greenrobot.common

Class ObjectCache<KEY,T>

java.lang.Object

de.greenrobot.common.ObjectCache<KEY,T>

public class ObjectCache<KEY,T>
extends Object

A simple in-memory object cache based on a ConcurrentHashMap and SoftReferences.

Author:

markus

Method Summary

Methods

Modifier and Type	Method and Description
void	cleanUp() Removes zombie entries (entries whose reference was set to null).
void	clear() Clears all cached entries.
boolean	containsKey(KEY key)
boolean	containsKeyWithValue(KEY key)
static <KEY,T> ObjectCache<KEY,T>	createUsingSoftReferences() Never use this for external allocations like bitmaps: they are not GCed (tested under Android 2.2)!
static <KEY,T> ObjectCache<KEY,T>	createUsingWeakReferences() Weak references are a bad cache but the work with external allocations like bitmaps.
T	get(KEY key) Get the cached entry or null if no valid cached entry is found.
boolean	isValueExpired(KEY key) Returns true if an entry was found with no value: mainly for testing purposes.
Set<KEY>	keySet()
T	put(KEY key, T object) Stores an new entry in the cache.
void	putAll(Map<KEY,T> mapDataToPut) Stores all entries contained in the given map in the cache.
T	remove(KEY key) Removes an entry from the cache.
int	size()

Methods inherited from class java.lang.Object

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

Method Detail

createUsingWeakReferences

public static <KEY,T> ObjectCache<KEY,T> createUsingWeakReferences()

Weak references are a bad cache but the work with external allocations like bitmaps.

createUsingSoftReferences

public static <KEY,T> ObjectCache<KEY,T> createUsingSoftReferences()

Never use this for external allocations like bitmaps: they are not GCed (tested under Android 2.2)!

put

public T put(KEY key,
    T object)

Stores an new entry in the cache.

putAll

public void putAll(Map<KEY,T> mapDataToPut)

Stores all entries contained in the given map in the cache.

get

public T get(KEY key)

Get the cached entry or null if no valid cached entry is found.

clear

public void clear()

Clears all cached entries.

remove

public T remove(KEY key)

Removes an entry from the cache. @return The removed entry

cleanUp

public void cleanUp()

Removes zombie entries (entries whose reference was set to null).

isValueExpired

public boolean isValueExpired(KEY key)

Returns true if an entry was found with no value: mainly for testing purposes.

containsKey

public boolean containsKey(KEY key)

containsKeyWithValue

public boolean containsKeyWithValue(KEY key)

keySet

public Set<KEY> keySet()

size

public int size()