org.apache.http.impl.client.cache.ehcache
Class EhcacheHttpCacheStorage

java.lang.Object
  org.apache.http.impl.client.cache.ehcache.EhcacheHttpCacheStorage

All Implemented Interfaces:

HttpCacheStorage

public class EhcacheHttpCacheStorage
extends Object
implements HttpCacheStorage

This class is a storage backend for cache entries that uses the popular Ehcache cache implementation. In particular, this backend allows for spillover to disk, where the cache can be effectively larger than memory, and cached responses are paged into and out of memory from disk as needed.

N.B. Since the Ehcache is configured ahead of time with a maximum number of cache entries, this effectively ignores the maximum cache entries specified by a provided CacheConfig.

Please refer to the Ehcache documentation for details on how to configure the Ehcache itself.

Since:

4.1

Constructor Summary

EhcacheHttpCacheStorage(net.sf.ehcache.Ehcache cache)
Constructs a storage backend using the provided Ehcache with default configuration options.

EhcacheHttpCacheStorage(net.sf.ehcache.Ehcache cache, CacheConfig config)
Constructs a storage backend using the provided Ehcache with the given configuration options.

EhcacheHttpCacheStorage(net.sf.ehcache.Ehcache cache, CacheConfig config, HttpCacheEntrySerializer serializer)
Constructs a storage backend using the provided Ehcache with the given configuration options, but using an alternative cache entry serialization strategy.

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Detail

EhcacheHttpCacheStorage

public EhcacheHttpCacheStorage(net.sf.ehcache.Ehcache cache)

Constructs a storage backend using the provided Ehcache with default configuration options.

Parameters:

cache - where to store cached origin responses

EhcacheHttpCacheStorage

public EhcacheHttpCacheStorage(net.sf.ehcache.Ehcache cache,
                               CacheConfig config)

Constructs a storage backend using the provided Ehcache with the given configuration options.

Parameters:

cache - where to store cached origin responses

config - cache storage configuration options - note that the setting for max object size will be ignored and should be configured in the Ehcache instead.

EhcacheHttpCacheStorage

public EhcacheHttpCacheStorage(net.sf.ehcache.Ehcache cache,
                               CacheConfig config,
                               HttpCacheEntrySerializer serializer)

Constructs a storage backend using the provided Ehcache with the given configuration options, but using an alternative cache entry serialization strategy.

Parameters:

cache - where to store cached origin responses

config - cache storage configuration options - note that the setting for max object size will be ignored and should be configured in the Ehcache instead.

serializer - alternative serialization mechanism

Method Detail

putEntry

public void putEntry(String key,
                     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:

key - where in the cache to store the entry

entry - cached response to store

Throws:

IOException

getEntry

public HttpCacheEntry getEntry(String key)
                        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:

key - cache key

Returns:

an HttpCacheEntry or null if no entry exists

Throws:

IOException

removeEntry

public void removeEntry(String key)

Description copied from interface: HttpCacheStorage

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

Specified by:

removeEntry in interface HttpCacheStorage

updateEntry

public void updateEntry(String key,
                        HttpCacheUpdateCallback callback)
                 throws IOException,
                        HttpCacheUpdateException

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:

key - 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

HttpCacheUpdateException