Class ConcurrentMapCache
- java.lang.Object
- org.springframework.cache.support.AbstractValueAdaptingCache
- org.springframework.cache.concurrent.ConcurrentMapCache
- All Implemented Interfaces:
Cache
public class ConcurrentMapCache extends AbstractValueAdaptingCache
SimpleCache
implementation based on the core JDKjava.util.concurrent
package.Useful for testing or simple caching scenarios, typically in combination with
SimpleCacheManager
or dynamically throughConcurrentMapCacheManager
.Note: As
ConcurrentHashMap
(the default implementation used) does not allow fornull
values to be stored, this class will replace them with a predefined internal object. This behavior can be changed through theConcurrentMapCache(String, ConcurrentMap, boolean)
constructor.- Since:
- 3.1
- Author:
- Costin Leau, Juergen Hoeller, Stephane Nicoll
- See Also:
ConcurrentMapCacheManager
Nested Class Summary
Nested classes/interfaces inherited from interface org.springframework.cache.Cache
Cache.ValueRetrievalException, Cache.ValueWrapper
Constructor Summary
Constructors Modifier Constructor Description ConcurrentMapCache(String name)
Create a new ConcurrentMapCache with the specified name.ConcurrentMapCache(String name, boolean allowNullValues)
Create a new ConcurrentMapCache with the specified name.ConcurrentMapCache(String name, ConcurrentMap<Object,Object> store, boolean allowNullValues)
Create a new ConcurrentMapCache with the specified name and the given internalConcurrentMap
to use.protected
ConcurrentMapCache(String name, ConcurrentMap<Object,Object> store, boolean allowNullValues, SerializationDelegate serialization)
Create a new ConcurrentMapCache with the specified name and the given internalConcurrentMap
to use.
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
clear()
Clear the cache through removing all mappings.void
evict(Object key)
Evict the mapping for this key from this cache if it is present.boolean
evictIfPresent(Object key)
Evict the mapping for this key from this cache if it is present, expecting the key to be immediately invisible for subsequent lookups.protected Object
fromStoreValue(Object storeValue)
Convert the given value from the internal store to a user value returned from the get method (adaptingnull
).<T> T
get(Object key, Callable<T> valueLoader)
Return the value to which this cache maps the specified key, obtaining that value fromvalueLoader
if necessary.String
getName()
Return the cache name.ConcurrentMap<Object,Object>
getNativeCache()
Return the underlying native cache provider.boolean
invalidate()
Invalidate the cache through removing all mappings, expecting all entries to be immediately invisible for subsequent lookups.boolean
isStoreByValue()
Return whether this cache stores a copy of each entry (true
) or a reference (false
, default).protected Object
lookup(Object key)
Perform an actual lookup in the underlying store.void
put(Object key, Object value)
Associate the specified value with the specified key in this cache.Cache.ValueWrapper
putIfAbsent(Object key, Object value)
Atomically associate the specified value with the specified key in this cache if it is not set already.protected Object
toStoreValue(Object userValue)
Convert the given user value, as passed into the put method, to a value in the internal store (adaptingnull
).Methods inherited from class org.springframework.cache.support.AbstractValueAdaptingCache
get, get, isAllowNullValues, toValueWrapper
Constructor Detail
ConcurrentMapCache
public ConcurrentMapCache(String name)
Create a new ConcurrentMapCache with the specified name.- Parameters:
name
- the name of the cache
ConcurrentMapCache
public ConcurrentMapCache(String name, boolean allowNullValues)
Create a new ConcurrentMapCache with the specified name.- Parameters:
name
- the name of the cacheallowNullValues
- whether to accept and convertnull
values for this cache
ConcurrentMapCache
public ConcurrentMapCache(String name, ConcurrentMap<Object,Object> store, boolean allowNullValues)
Create a new ConcurrentMapCache with the specified name and the given internalConcurrentMap
to use.- Parameters:
name
- the name of the cachestore
- the ConcurrentMap to use as an internal storeallowNullValues
- whether to allownull
values (adapting them to an internal null holder value)
ConcurrentMapCache
protected ConcurrentMapCache(String name, ConcurrentMap<Object,Object> store, boolean allowNullValues, @Nullable SerializationDelegate serialization)
Create a new ConcurrentMapCache with the specified name and the given internalConcurrentMap
to use. If theSerializationDelegate
is specified,store-by-value
is enabled- Parameters:
name
- the name of the cachestore
- the ConcurrentMap to use as an internal storeallowNullValues
- whether to allownull
values (adapting them to an internal null holder value)serialization
- theSerializationDelegate
to use to serialize cache entry ornull
to store the reference- Since:
- 4.3
Method Detail
isStoreByValue
public final boolean isStoreByValue()
Return whether this cache stores a copy of each entry (true
) or a reference (false
, default). If store by value is enabled, each entry in the cache must be serializable.- Since:
- 4.3
getNativeCache
public final ConcurrentMap<Object,Object> getNativeCache()
Description copied from interface:Cache
Return the underlying native cache provider.
lookup
@Nullable protected Object lookup(Object key)
Description copied from class:AbstractValueAdaptingCache
Perform an actual lookup in the underlying store.- Specified by:
lookup
in classAbstractValueAdaptingCache
- Parameters:
key
- the key whose associated value is to be returned- Returns:
- the raw store value for the key, or
null
if none
get
@Nullable public <T> T get(Object key, Callable<T> valueLoader)
Description copied from interface:Cache
Return the value to which this cache maps the specified key, obtaining that value fromvalueLoader
if necessary. This method provides a simple substitute for the conventional "if cached, return; otherwise create, cache and return" pattern.If possible, implementations should ensure that the loading operation is synchronized so that the specified
valueLoader
is only called once in case of concurrent access on the same key.If the
valueLoader
throws an exception, it is wrapped in aCache.ValueRetrievalException
- Parameters:
key
- the key whose associated value is to be returned- Returns:
- the value to which this cache maps the specified key
- See Also:
Cache.get(Object)
put
public void put(Object key, @Nullable Object value)
Description copied from interface:Cache
Associate the specified value with the specified key in this cache.If the cache previously contained a mapping for this key, the old value is replaced by the specified value.
Actual registration may be performed in an asynchronous or deferred fashion, with subsequent lookups possibly not seeing the entry yet. This may for example be the case with transactional cache decorators. Use
Cache.putIfAbsent(java.lang.Object, java.lang.Object)
for guaranteed immediate registration.- Parameters:
key
- the key with which the specified value is to be associatedvalue
- the value to be associated with the specified key- See Also:
Cache.putIfAbsent(Object, Object)
putIfAbsent
@Nullable public Cache.ValueWrapper putIfAbsent(Object key, @Nullable Object value)
Description copied from interface:Cache
Atomically associate the specified value with the specified key in this cache if it is not set already.This is equivalent to:
except that the action is performed atomically. While all out-of-the-boxValueWrapper existingValue = cache.get(key); if (existingValue == null) { cache.put(key, value); } return existingValue;
CacheManager
implementations are able to perform the put atomically, the operation may also be implemented in two steps, e.g. with a check for presence and a subsequent put, in a non-atomic way. Check the documentation of the native cache implementation that you are using for more details.The default implementation delegates to
Cache.get(Object)
andCache.put(Object, Object)
along the lines of the code snippet above.- Parameters:
key
- the key with which the specified value is to be associatedvalue
- the value to be associated with the specified key- Returns:
- the value to which this cache maps the specified key (which may be
null
itself), or alsonull
if the cache did not contain any mapping for that key prior to this call. Returningnull
is therefore an indicator that the givenvalue
has been associated with the key. - See Also:
Cache.put(Object, Object)
evict
public void evict(Object key)
Description copied from interface:Cache
Evict the mapping for this key from this cache if it is present.Actual eviction may be performed in an asynchronous or deferred fashion, with subsequent lookups possibly still seeing the entry. This may for example be the case with transactional cache decorators. Use
Cache.evictIfPresent(java.lang.Object)
for guaranteed immediate removal.- Parameters:
key
- the key whose mapping is to be removed from the cache- See Also:
Cache.evictIfPresent(Object)
evictIfPresent
public boolean evictIfPresent(Object key)
Description copied from interface:Cache
Evict the mapping for this key from this cache if it is present, expecting the key to be immediately invisible for subsequent lookups.The default implementation delegates to
Cache.evict(Object)
, returningfalse
for not-determined prior presence of the key. Cache providers and in particular cache decorators are encouraged to perform immediate eviction if possible (e.g. in case of generally deferred cache operations within a transaction) and to reliably determine prior presence of the given key.- Parameters:
key
- the key whose mapping is to be removed from the cache- Returns:
true
if the cache was known to have a mapping for this key before,false
if it did not (or if prior presence could not be determined)- See Also:
Cache.evict(Object)
clear
public void clear()
Description copied from interface:Cache
Clear the cache through removing all mappings.Actual clearing may be performed in an asynchronous or deferred fashion, with subsequent lookups possibly still seeing the entries. This may for example be the case with transactional cache decorators. Use
Cache.invalidate()
for guaranteed immediate removal of entries.- See Also:
Cache.invalidate()
invalidate
public boolean invalidate()
Description copied from interface:Cache
Invalidate the cache through removing all mappings, expecting all entries to be immediately invisible for subsequent lookups.- Returns:
true
if the cache was known to have mappings before,false
if it did not (or if prior presence of entries could not be determined)- See Also:
Cache.clear()
toStoreValue
protected Object toStoreValue(@Nullable Object userValue)
Description copied from class:AbstractValueAdaptingCache
Convert the given user value, as passed into the put method, to a value in the internal store (adaptingnull
).- Overrides:
toStoreValue
in classAbstractValueAdaptingCache
- Parameters:
userValue
- the given user value- Returns:
- the value to store
fromStoreValue
protected Object fromStoreValue(@Nullable Object storeValue)
Description copied from class:AbstractValueAdaptingCache
Convert the given value from the internal store to a user value returned from the get method (adaptingnull
).- Overrides:
fromStoreValue
in classAbstractValueAdaptingCache
- Parameters:
storeValue
- the store value- Returns:
- the value to return to the user