Top Description Fields Constructors Methods
org.springframework.cache.transaction

public Class TransactionAwareCacheDecorator

extends Object
implements Cache
Class Inheritance
All Implemented Interfaces
org.springframework.cache.Cache
Imports
java.util.concurrent.Callable, .CompletableFuture, java.util.function.Supplier, org.springframework.cache.Cache, org.springframework.lang.Nullable, org.springframework.transaction.support.TransactionSynchronization, .TransactionSynchronizationManager, org.springframework.util.Assert
Cache decorator which synchronizes its put, evict 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, evict and clear operations will be performed immediately, as usual.

Note

Use of immediate operations such as putIfAbsent and evictIfPresent cannot be deferred to the after-commit phase of a running transaction. Use these with care in a transactional environment.

Authors
Juergen Hoeller, Stephane Nicoll, Stas Volsky
Since
3.2
See Also
TransactionAwareCacheManagerProxy

Field Summary

Modifier and TypeField and Description
private final Cache
targetCache

Constructor Summary

AccessConstructor and Description
public
TransactionAwareCacheDecorator(Cache
the target Cache to decorate
targetCache)

Create a new TransactionAwareCache for the given target Cache.

Method Summary

Modifier and TypeMethod and Description
public void
clear()

Implements org.springframework.cache.Cache.clear.

Clear the cache through removing all mappings.

public void
evict(final Object
the key whose mapping is to be removed from the cache
key)

Implements org.springframework.cache.Cache.evict.

Evict the mapping for this key from this cache if it is present.

public boolean
evictIfPresent(Object
the key whose mapping is to be removed from the cache
key)

Overrides default org.springframework.cache.Cache.evictIfPresent.

Evict the mapping for this key from this cache if it is present, expecting the key to be immediately invisible for subsequent lookups.

public Cache.ValueWrapper
get(Object
the key whose associated value is to be returned
key)

Implements org.springframework.cache.Cache.get.

Return the value to which this cache maps the specified key.

public <T> T
get(Object
the key whose associated value is to be returned
key, Class<T>
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)
type)

Implements org.springframework.cache.Cache.get.

Return the value to which this cache maps the specified key, generically specifying a type that return value will be cast to.

public <T> T
get(Object
the key whose associated value is to be returned
key, Callable<T> valueLoader)

Implements org.springframework.cache.Cache.get.

Return the value to which this cache maps the specified key, obtaining that value from valueLoader if necessary.

public String
getName()

Implements org.springframework.cache.Cache.getName.

Return the cache name.

public Object
getNativeCache()

Implements org.springframework.cache.Cache.getNativeCache.

Return the underlying native cache provider.

public Cache
getTargetCache()

Return the target Cache that this Cache should delegate to.

public boolean
invalidate()

Overrides default org.springframework.cache.Cache.invalidate.

Invalidate the cache through removing all mappings, expecting all entries to be immediately invisible for subsequent lookups.

public void
put(final Object
the key with which the specified value is to be associated
key, final Object
the value to be associated with the specified key
value)

Implements org.springframework.cache.Cache.put.

Associate the specified value with the specified key in this cache.

public Cache.ValueWrapper
putIfAbsent(Object
the key with which the specified value is to be associated
key, Object
the value to be associated with the specified key
value)

Overrides default org.springframework.cache.Cache.putIfAbsent.

Atomically associate the specified value with the specified key in this cache if it is not set already.

public CompletableFuture<?>
retrieve(Object
the key whose associated value is to be returned
key)

Overrides default org.springframework.cache.Cache.retrieve.

Return the value to which this cache maps the specified key, wrapped in a CompletableFuture.

public <T> CompletableFuture<T>
retrieve(Object
the key whose associated value is to be returned
key, Supplier<CompletableFuture<T>> valueLoader)

Overrides default org.springframework.cache.Cache.retrieve.

Return the value to which this cache maps the specified key, obtaining that value from valueLoader if necessary.

Inherited from java.lang.Object:
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Field Detail

targetCacheback to summary
private final Cache targetCache

Constructor Detail

TransactionAwareCacheDecoratorback to summary
public TransactionAwareCacheDecorator(Cache targetCache)

Create a new TransactionAwareCache for the given target Cache.

Parameters
targetCache:Cache

the target Cache to decorate

Method Detail

clearback to summary
public void clear()

Implements org.springframework.cache.Cache.clear.

Doc from org.springframework.cache.Cache.clear.

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 invalidate() for guaranteed immediate removal of entries.

If the cache is supposed to be compatible with CompletableFuture and reactive interactions, the clear operation needs to be effectively non-blocking, with any backend write-through happening asynchronously. This goes along with a cache implemented and configured to support retrieve(Object) and retrieve(Object, Supplier).

Annotations
@Override
evictback to summary
public void evict(final Object key)

Implements org.springframework.cache.Cache.evict.

Doc from org.springframework.cache.Cache.evict.

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 evictIfPresent for guaranteed immediate removal.

If the cache is supposed to be compatible with CompletableFuture and reactive interactions, the evict operation needs to be effectively non-blocking, with any backend write-through happening asynchronously. This goes along with a cache implemented and configured to support retrieve(Object) and retrieve(Object, Supplier).

Parameters
key:Object

the key whose mapping is to be removed from the cache

Annotations
@Override
evictIfPresentback to summary
public boolean evictIfPresent(Object key)

Overrides default org.springframework.cache.Cache.evictIfPresent.

Doc from org.springframework.cache.Cache.evictIfPresent.

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 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.

Parameters
key:Object

the key whose mapping is to be removed from the cache

Returns:boolean

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)

Annotations
@Override
getback to summary
public Cache.ValueWrapper get(Object key)

Implements org.springframework.cache.Cache.get.

Doc from org.springframework.cache.Cache.get.

Return the value to which this cache maps the specified key.

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 ValueWrapper.

Parameters
key:Object

the key whose associated value is to be returned

Returns:Cache.ValueWrapper

the value to which this cache maps the specified key, contained within a ValueWrapper which may also hold a cached null value. A straight null being returned means that the cache contains no mapping for this key.

Annotations
@Override
@Nullable
getback to summary
public <T> T get(Object key, Class<T> type)

Implements org.springframework.cache.Cache.get.

Doc from org.springframework.cache.Cache.get.

Return the value to which this cache maps the specified key, generically specifying a type that return value will be cast to.

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 get(Object) variant for that purpose instead.

Parameters
key:Object

the key whose associated value is to be returned

type:Class<T>

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)

Returns:T

the value to which this cache maps the specified key (which may be null itself), or also null if the cache contains no mapping for this key

Annotations
@Override
getback to summary
public <T> T get(Object key, Callable<T> valueLoader)

Implements org.springframework.cache.Cache.get.

Doc from org.springframework.cache.Cache.get.

Return the value to which this cache maps the specified key, obtaining that value from 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 ValueRetrievalException

Parameters
key:Object

the key whose associated value is to be returned

Returns:T

the value to which this cache maps the specified key

Annotations
@Override
@Nullable
getNameback to summary
public String getName()

Implements org.springframework.cache.Cache.getName.

Doc from org.springframework.cache.Cache.getName.

Return the cache name.

Annotations
@Override
getNativeCacheback to summary
public Object getNativeCache()

Implements org.springframework.cache.Cache.getNativeCache.

Doc from org.springframework.cache.Cache.getNativeCache.

Return the underlying native cache provider.

Annotations
@Override
getTargetCacheback to summary
public Cache getTargetCache()

Return the target Cache that this Cache should delegate to.

invalidateback to summary
public boolean invalidate()

Overrides default org.springframework.cache.Cache.invalidate.

Doc from org.springframework.cache.Cache.invalidate.

Invalidate the cache through removing all mappings, expecting all entries to be immediately invisible for subsequent lookups.

Returns:boolean

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)

Annotations
@Override
putback to summary
public void put(final Object key, final Object value)

Implements org.springframework.cache.Cache.put.

Doc from org.springframework.cache.Cache.put.

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 putIfAbsent for guaranteed immediate registration.

If the cache is supposed to be compatible with CompletableFuture and reactive interactions, the put operation needs to be effectively non-blocking, with any backend write-through happening asynchronously. This goes along with a cache implemented and configured to support retrieve(Object) and retrieve(Object, Supplier).

Parameters
key:Object

the key with which the specified value is to be associated

value:Object

the value to be associated with the specified key

Annotations
@Override
putIfAbsentback to summary
public Cache.ValueWrapper putIfAbsent(Object key, Object value)

Overrides default org.springframework.cache.Cache.putIfAbsent.

Doc from org.springframework.cache.Cache.putIfAbsent.

Atomically associate the specified value with the specified key in this cache if it is not set already.

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 get(Object) and put(Object, Object) along the lines of the code snippet above.

Parameters
key:Object

the key with which the specified value is to be associated

value:Object

the value to be associated with the specified key

Returns:Cache.ValueWrapper

the value to which this cache maps the specified key (which may be null 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.

Annotations
@Override
@Nullable
retrieveback to summary
public CompletableFuture<?> retrieve(Object key)

Overrides default org.springframework.cache.Cache.retrieve.

Doc from org.springframework.cache.Cache.retrieve.

Return the value to which this cache maps the specified key, wrapped in a CompletableFuture. This operation must not block but is allowed to return a completed CompletableFuture if the corresponding value is immediately available.

Can return null if the cache can immediately determine that it contains no mapping for this key (e.g. through an in-memory key map). Otherwise, the cached value will be returned in the CompletableFuture, with null indicating a late-determined cache miss. A nested ValueWrapper potentially indicates a nullable cached value; the cached value may also be represented as a plain element if null values are not supported. Calling code needs to be prepared to handle all those variants of the result returned by this method.

Parameters
key:Object

the key whose associated value is to be returned

Returns:CompletableFuture<?>

the value to which this cache maps the specified key, contained within a CompletableFuture which may also be empty when a cache miss has been late-determined. A straight null being returned means that the cache immediately determined that it contains no mapping for this key. A ValueWrapper contained within the CompletableFuture indicates a cached value that is potentially null; this is sensible in a late-determined scenario where a regular CompletableFuture-contained null indicates a cache miss. However, a cache may also return a plain value if it does not support the actual caching of null values, avoiding the extra level of value wrapping. Spring's cache processing can deal with all such implementation strategies.

Annotations
@Override
@Nullable
retrieveback to summary
public <T> CompletableFuture<T> retrieve(Object key, Supplier<CompletableFuture<T>> valueLoader)

Overrides default org.springframework.cache.Cache.retrieve.

Doc from org.springframework.cache.Cache.retrieve.

Return the value to which this cache maps the specified key, obtaining that value from valueLoader if necessary. This method provides a simple substitute for the conventional "if cached, return; otherwise create, cache and return" pattern, based on CompletableFuture. This operation must not block.

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.

Null values always indicate a user-level null value with this method. The provided CompletableFuture handle produces a value or raises an exception. If the valueLoader raises an exception, it will be propagated to the returned CompletableFuture handle.

Parameters
key:Object

the key whose associated value is to be returned

Returns:CompletableFuture<T>

the value to which this cache maps the specified key, contained within a CompletableFuture which will never be null. The provided future is expected to produce a value or raise an exception.

Annotations
@Override