public class TransactionAwareCacheDecorator extends Object implements Cache
put(java.lang.Object, java.lang.Object)
, evict(java.lang.Object)
and
clear()
operations with Spring-managed transactions (through Spring's
TransactionSynchronizationManager
, performing the actual cache
put/evict/clear operation only in the after-commit phase of a successful
transaction. If no transaction is active, put(java.lang.Object, java.lang.Object)
, evict(java.lang.Object)
and
clear()
operations will be performed immediately, as usual.
Note: Use of immediate operations such as putIfAbsent(java.lang.Object, java.lang.Object)
and
evictIfPresent(java.lang.Object)
cannot be deferred to the after-commit phase of a
running transaction. Use these with care in a transactional environment.
TransactionAwareCacheManagerProxy
Cache.ValueRetrievalException, Cache.ValueWrapper
Constructor and Description |
---|
TransactionAwareCacheDecorator(Cache targetCache)
Create a new TransactionAwareCache for the given target Cache.
|
Modifier and Type | Method and 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.
|
Cache.ValueWrapper |
get(Object key)
Return the value to which this cache maps the specified key.
|
<T> T |
get(Object key,
Callable<T> valueLoader)
Return the value to which this cache maps the specified key, obtaining
that value from
valueLoader if necessary. |
<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.
|
Object |
getNativeCache()
Return the underlying native cache provider.
|
Cache |
getTargetCache()
Return the target Cache that this Cache should delegate to.
|
boolean |
invalidate()
Invalidate the cache through removing all mappings, expecting all
entries to be immediately invisible for subsequent lookups.
|
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.
|
public TransactionAwareCacheDecorator(Cache targetCache)
targetCache
- the target Cache to decoratepublic Cache getTargetCache()
public Object getNativeCache()
Cache
getNativeCache
in interface Cache
@Nullable 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)
,
Cache.get(Object, Callable)
public <T> T get(Object key, @Nullable 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)
@Nullable public <T> T get(Object key, Callable<T> valueLoader)
Cache
valueLoader
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
a Cache.ValueRetrievalException
get
in interface Cache
key
- the key whose associated value is to be returnedCache.get(Object)
public void put(Object key, @Nullable Object value)
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.
put
in interface Cache
key
- the key with which the specified value is to be associatedvalue
- the value to be associated with the specified keyCache.putIfAbsent(Object, Object)
@Nullable public Cache.ValueWrapper putIfAbsent(Object key, @Nullable Object value)
Cache
This is equivalent to:
ValueWrapper existingValue = cache.get(key);
if (existingValue == null) {
cache.put(key, value);
}
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.
The default implementation delegates to Cache.get(Object)
and
Cache.put(Object, Object)
along the lines of the code snippet above.
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.Cache.put(Object, Object)
public void evict(Object key)
Cache
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.
evict
in interface Cache
key
- the key whose mapping is to be removed from the cacheCache.evictIfPresent(Object)
public boolean evictIfPresent(Object key)
Cache
The default implementation delegates to Cache.evict(Object)
,
returning false
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.
evictIfPresent
in interface Cache
key
- the key whose mapping is to be removed from the cachetrue
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)Cache.evict(Object)
public void clear()
Cache
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.
clear
in interface Cache
Cache.invalidate()
public boolean invalidate()
Cache
invalidate
in interface Cache
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)Cache.clear()