Package org.apache.http.impl.client.cache

Class ManagedHttpCacheStorage

java.lang.Object

org.apache.http.impl.client.cache.ManagedHttpCacheStorage

All Implemented Interfaces:

Closeable, AutoCloseable, HttpCacheStorage

@Contract(threading=SAFE)
public class ManagedHttpCacheStorage
extends Object
implements HttpCacheStorage, Closeable

HttpCacheStorage implementation capable of deallocating resources associated with the cache entries.

This cache keeps track of cache entries using PhantomReference and maintains a collection of all resources that are no longer in use. The cache, however, does not automatically deallocates associated resources by invoking Resource.dispose() method. The consumer MUST periodically call cleanResources() method to trigger resource deallocation. The cache can be permanently shut down using shutdown() method. All resources associated with the entries used by the cache will be deallocated.

This HttpCacheStorage implementation is intended for use with FileResource and similar.

Compatibility note. Prior to version 4.4 this storage implementation used to dispose of all resource entries upon close(). As of version 4.4 the close() method disposes only of those resources that have been explicitly removed from the cache with removeEntry(String) method.

The shutdown() ()} method can still be used to shut down the storage and dispose of all resources currently managed by it.

Since:

4.1

Constructor Summary

Constructors

Constructor	Description
ManagedHttpCacheStorage(CacheConfig config)

Method Summary

Modifier and Type	Method	Description
void	cleanResources()
void	close()
HttpCacheEntry	getEntry(String url)	Retrieves the cache entry stored under the given key or null if no entry exists under that key.
void	putEntry(String url, HttpCacheEntry entry)	Store a given cache entry under the given key.
void	removeEntry(String url)	Deletes/invalidates/removes any cache entries currently stored under the given key.
void	shutdown()
void	updateEntry(String url, HttpCacheUpdateCallback callback)	Atomically applies the given callback to update an existing cache entry under a given key.

Methods inherited from class java.lang.Object

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

Constructor Detail

ManagedHttpCacheStorage

public ManagedHttpCacheStorage(CacheConfig config)

Method Detail

putEntry

public void putEntry(String url,
                     HttpCacheEntry entry)
              throws IOException

Description copied from interface: HttpCacheStorage

Store a given cache entry under the given key.

Specified by:

putEntry in interface HttpCacheStorage

Parameters:

url - where in the cache to store the entry

entry - cached response to store

Throws:

IOException

getEntry

public HttpCacheEntry getEntry(String url)
                        throws IOException

Description copied from interface: HttpCacheStorage

Retrieves the cache entry stored under the given key or null if no entry exists under that key.

Specified by:

getEntry in interface HttpCacheStorage

Parameters:

url - cache key

Returns:

an HttpCacheEntry or null if no entry exists

Throws:

IOException

removeEntry

public void removeEntry(String url)
                 throws IOException

Description copied from interface: HttpCacheStorage

Deletes/invalidates/removes any cache entries currently stored under the given key.

Specified by:

removeEntry in interface HttpCacheStorage

Throws:

IOException

updateEntry

public void updateEntry(String url,
                        HttpCacheUpdateCallback callback)
                 throws IOException

Description copied from interface: HttpCacheStorage

Atomically applies the given callback to update an existing cache entry under a given key.

Specified by:

updateEntry in interface HttpCacheStorage

Parameters:

url - indicates which entry to modify

callback - performs the update; see HttpCacheUpdateCallback for details, but roughly the callback expects to be handed the current entry and will return the new value for the entry.

Throws:

IOException

cleanResources

public void cleanResources()

shutdown

public void shutdown()

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable