Package org.apache.cayenne.cache

Class NestedQueryCache

java.lang.Object

org.apache.cayenne.cache.NestedQueryCache

All Implemented Interfaces:

QueryCache

public class NestedQueryCache
extends Object
implements QueryCache

A QueryCache wrapper that introduces a key namespace on top of a delegate shared cache. This way multiple cache users can share the same underlying cache without a possibility of key conflicts, yet refresh the cache groups in a coordinated fashion.

Since:

3.0

Field Summary

Fields

Modifier and Type	Field	Description
protected QueryCache	delegate
protected String	namespace

Constructor Summary

Constructors

Constructor	Description
NestedQueryCache(QueryCache delegate)

Method Summary

Modifier and Type	Method	Description
void	clear()	Deprecated. since 4.0
List	get(QueryMetadata metadata)	Returns a cached query result for the given QueryMetadata or null if the result is not cached or is expired.
List	get(QueryMetadata metadata, QueryCacheEntryFactory factory)	Returns a cached query result for the given QueryMetadata.
QueryCache	getDelegate()	Returns the actual implementation of the query cache that is wrapped by this NestedQueryCache.
void	put(QueryMetadata metadata, List results)
void	remove(String key)	Removes an entry for key in the current namespace.
void	removeGroup(String groupKey)	Invalidates a shared cache group.
void	removeGroup(String groupKey, Class<?> keyType, Class<?> valueType)	Removes a group of entries identified by group key.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

delegate

protected QueryCache delegate

namespace

protected String namespace

Constructor Details

NestedQueryCache

public NestedQueryCache(QueryCache delegate)

Method Details

getDelegate

public QueryCache getDelegate()

Returns the actual implementation of the query cache that is wrapped by this NestedQueryCache.

clear

@Deprecated
public void clear()

Deprecated.

since 4.0

Clears the underlying shared cache.

Specified by:

clear in interface QueryCache

See Also:

• QueryCache.clear()

get

public List get(QueryMetadata metadata,
 QueryCacheEntryFactory factory)

Description copied from interface: QueryCache

Returns a cached query result for the given QueryMetadata. If the result is not cached or is expired, cache will use provided factory to rebuild the value and store it in the cache. A corollary is that this method never returns null.

Compared to QueryCache.get(QueryMetadata), this method allows the cache to do appropriate synchronization when refreshing the entry, preventing multiple threads from running the same query when a missing entry is requested by multiple threads simultaneously.

Specified by:

get in interface QueryCache

get

public List get(QueryMetadata metadata)

Description copied from interface: QueryCache

Returns a cached query result for the given QueryMetadata or null if the result is not cached or is expired.

Specified by:

get in interface QueryCache

put

public void put(QueryMetadata metadata,
 List results)

Specified by:

put in interface QueryCache

remove

public void remove(String key)

Removes an entry for key in the current namespace.

Specified by:

remove in interface QueryCache

removeGroup

public void removeGroup(String groupKey)

Invalidates a shared cache group.

Specified by:

removeGroup in interface QueryCache

removeGroup

public void removeGroup(String groupKey,
 Class<?> keyType,
 Class<?> valueType)

Description copied from interface: QueryCache

Removes a group of entries identified by group key. Can be used if cache provider supports strictly typed caches.

Specified by:

removeGroup in interface QueryCache

See Also:

• QueryCache.removeGroup(String)