Cache.ValueWrapper
Constructor and Description |
---|
GuavaCache(String name,
com.google.common.cache.Cache<Object,Object> cache)
Create a
GuavaCache instance with the specified name and the
given internal Cache to use. |
GuavaCache(String name,
com.google.common.cache.Cache<Object,Object> cache,
boolean allowNullValues)
Create a
GuavaCache instance with the specified name and the
given internal Cache to use. |
Modifier and Type | Method and Description |
---|---|
void |
clear()
Remove all mappings from the cache.
|
void |
evict(Object key)
Evict the mapping for this key from this cache if it is present.
|
protected Object |
fromStoreValue(Object storeValue)
Convert the given value from the internal store to a user value
returned from the get method (adapting
null ). |
Cache.ValueWrapper |
get(Object key)
Return the value to which this cache maps the specified key.
|
<T> T |
get(Object key,
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.
|
String |
getName()
Return the cache name.
|
com.google.common.cache.Cache<Object,Object> |
getNativeCache()
Return the the underlying native cache provider.
|
boolean |
isAllowNullValues() |
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 (adapting
null ). |
public GuavaCache(String name, com.google.common.cache.Cache<Object,Object> cache)
GuavaCache
instance with the specified name and the
given internal Cache
to use.name
- the name of the cachecache
- the backing Guava Cache instancepublic GuavaCache(String name, com.google.common.cache.Cache<Object,Object> cache, boolean allowNullValues)
GuavaCache
instance with the specified name and the
given internal Cache
to use.name
- the name of the cachecache
- the backing Guava Cache instanceallowNullValues
- whether to accept and convert null
values for this cachepublic final String getName()
Cache
public final com.google.common.cache.Cache<Object,Object> getNativeCache()
Cache
getNativeCache
in interface Cache
public final boolean isAllowNullValues()
public Cache.ValueWrapper get(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(Object key, 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(Object key, Object value)
Cache
If the cache previously contained a mapping for this key, the old value is replaced by the specified value.
public Cache.ValueWrapper putIfAbsent(Object key, Object value)
Cache
This is equivalent to:
Object existingValue = cache.get(key);
if (existingValue == null) {
cache.put(key, value);
return null;
} else {
return existingValue;
}
except that the action is performed atomically. While all out-of-the-box
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.putIfAbsent
in interface Cache
key
- the key with which the specified value is to be associatedvalue
- the value to be associated with the specified keynull
itself), or also null
if the cache did not contain any
mapping for that key prior to this call. Returning null
is therefore
an indicator that the given value
has been associated with the key.public void evict(Object key)
Cache
public void clear()
Cache
protected Object fromStoreValue(Object storeValue)
null
).storeValue
- the store value