public class ConcurrentMapCache extends java.lang.Object implements Cache
Cache
implementation based on the core JDK
java.util.concurrent
package.
Useful for testing or simple caching scenarios, typically in combination
with SimpleCacheManager
or
dynamically through ConcurrentMapCacheManager
.
Note: As ConcurrentHashMap
(the default implementation used)
does not allow for null
values to be stored, this class will replace
them with a predefined internal object. This behavior can be changed through the
ConcurrentMapCache(String, ConcurrentMap, boolean)
constructor.
Modifier and Type | Class and Description |
---|---|
private static class |
ConcurrentMapCache.NullHolder |
Cache.ValueWrapper
Modifier and Type | Field and Description |
---|---|
private boolean |
allowNullValues |
private java.lang.String |
name |
private static java.lang.Object |
NULL_HOLDER |
private java.util.concurrent.ConcurrentMap<java.lang.Object,java.lang.Object> |
store |
Constructor and Description |
---|
ConcurrentMapCache(java.lang.String name)
Create a new ConcurrentMapCache with the specified name.
|
ConcurrentMapCache(java.lang.String name,
boolean allowNullValues)
Create a new ConcurrentMapCache with the specified name.
|
ConcurrentMapCache(java.lang.String name,
java.util.concurrent.ConcurrentMap<java.lang.Object,java.lang.Object> store,
boolean allowNullValues)
Create a new ConcurrentMapCache with the specified name and the
given internal ConcurrentMap to use.
|
Modifier and Type | Method and Description |
---|---|
void |
clear()
Remove all mappings from the cache.
|
void |
evict(java.lang.Object key)
Evict the mapping for this key from this cache if it is present.
|
protected java.lang.Object |
fromStoreValue(java.lang.Object storeValue)
Convert the given value from the internal store to a user value
returned from the get method (adapting
null ). |
Cache.ValueWrapper |
get(java.lang.Object key)
Return the value to which this cache maps the specified key.
|
<T> T |
get(java.lang.Object key,
java.lang.Class<T> type)
Return the value to which this cache maps the specified key,
generically specifying a type that return value will be cast to.
|
java.lang.String |
getName()
Return the cache name.
|
java.util.concurrent.ConcurrentMap<java.lang.Object,java.lang.Object> |
getNativeCache()
Return the the underlying native cache provider.
|
boolean |
isAllowNullValues() |
void |
put(java.lang.Object key,
java.lang.Object value)
Associate the specified value with the specified key in this cache.
|
protected java.lang.Object |
toStoreValue(java.lang.Object userValue)
Convert the given user value, as passed into the put method,
to a value in the internal store (adapting
null ). |
private static final java.lang.Object NULL_HOLDER
private final java.lang.String name
private final java.util.concurrent.ConcurrentMap<java.lang.Object,java.lang.Object> store
private final boolean allowNullValues
public ConcurrentMapCache(java.lang.String name)
name
- the name of the cachepublic ConcurrentMapCache(java.lang.String name, boolean allowNullValues)
name
- the name of the cacheallowNullValues
- whether to accept and convert null values for this cachepublic ConcurrentMapCache(java.lang.String name, java.util.concurrent.ConcurrentMap<java.lang.Object,java.lang.Object> store, boolean allowNullValues)
name
- the name of the cachestore
- the ConcurrentMap to use as an internal storeallowNullValues
- whether to allow null
values
(adapting them to an internal null holder value)public final java.lang.String getName()
Cache
public final java.util.concurrent.ConcurrentMap<java.lang.Object,java.lang.Object> getNativeCache()
Cache
getNativeCache
in interface Cache
public final boolean isAllowNullValues()
public Cache.ValueWrapper get(java.lang.Object key)
Cache
Returns null
if the cache contains no mapping for this key;
otherwise, the cached value (which may be null
itself) will
be returned in a Cache.ValueWrapper
.
get
in interface Cache
key
- the key whose associated value is to be returnedCache.ValueWrapper
which may also hold
a cached null
value. A straight null
being
returned means that the cache contains no mapping for this key.Cache.get(Object, Class)
public <T> T get(java.lang.Object key, java.lang.Class<T> type)
Cache
Note: This variant of get
does not allow for differentiating
between a cached null
value and no cache entry found at all.
Use the standard Cache.get(Object)
variant for that purpose instead.
get
in interface Cache
key
- the key whose associated value is to be returnedtype
- the required type of the returned value (may be
null
to bypass a type check; in case of a null
value found in the cache, the specified type is irrelevant)null
itself), or also null
if
the cache contains no mapping for this keyCache.get(Object)
public void put(java.lang.Object key, java.lang.Object value)
Cache
If the cache previously contained a mapping for this key, the old value is replaced by the specified value.
public void evict(java.lang.Object key)
Cache
public void clear()
Cache
protected java.lang.Object fromStoreValue(java.lang.Object storeValue)
null
).storeValue
- the store valueprotected java.lang.Object toStoreValue(java.lang.Object userValue)
null
).userValue
- the given user value