com.communote.server.core.image.caching

Class ImageCacheElementProvider

java.lang.Object

com.communote.server.core.image.caching.ImageCacheElementProvider

All Implemented Interfaces:

AccessRestrictedCacheElementProvider<ImageCacheKey,Image>, CacheElementProvider<ImageCacheKey,Image>

public class ImageCacheElementProvider
extends Object
implements AccessRestrictedCacheElementProvider<ImageCacheKey,Image>

Provider which loads the unscaled images of a certain image type using an ImageProvider.

Author:

Communote GmbH - http://www.communote.com/

Field Summary

Fields inherited from interface com.communote.server.core.common.caching.CacheElementProvider

ETERNAL_TIME_TO_LIVE

Constructor Summary

Constructors

Constructor and Description
ImageCacheElementProvider(String typeName, ImageProvider imageProvider, ImageDiskCache diskCache)

Method Summary

Modifier and Type	Method and Description
void	assertAccess(ImageCacheKey cacheKey)
String	getContentType() Returns a unique string naming the content type of the elements provided by this provider (e.g.
int	getTimeToLive() Returns the time in seconds describing how long a provided element will be cached without expiring (when it is not replaced manually).
Image	load(ImageCacheKey key) Provides an element identified by the key for caching.

Methods inherited from class java.lang.Object

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

Constructor Detail

ImageCacheElementProvider

public ImageCacheElementProvider(String typeName,
                                 ImageProvider imageProvider,
                                 ImageDiskCache diskCache)

Parameters:

typeName - The type this provider is used for.

imageProvider - The image provider.

diskCache - storage for caching images locally as files on disk

Method Detail

assertAccess

public void assertAccess(ImageCacheKey cacheKey)
                  throws AuthorizationException

Specified by:

assertAccess in interface AccessRestrictedCacheElementProvider<ImageCacheKey,Image>

Parameters:

cacheKey - The key to check access against.

Throws:

AuthorizationException - Thrown, when the user is not allowed to access the item.

getContentType

public String getContentType()

Description copied from interface: CacheElementProvider

Returns a unique string naming the content type of the elements provided by this provider (e.g. 'image' when providing image data).

Specified by:

getContentType in interface CacheElementProvider<ImageCacheKey,Image>

Returns:

the string name

getTimeToLive

public int getTimeToLive()

Description copied from interface: CacheElementProvider

Returns the time in seconds describing how long a provided element will be cached without expiring (when it is not replaced manually). Return CacheElementProvider.ETERNAL_TIME_TO_LIVE when the element should never expire.

Specified by:

getTimeToLive in interface CacheElementProvider<ImageCacheKey,Image>

Returns:

image time to live

load

public Image load(ImageCacheKey key)
           throws CacheElementProviderException

Description copied from interface: CacheElementProvider

Provides an element identified by the key for caching.

Specified by:

load in interface CacheElementProvider<ImageCacheKey,Image>

Parameters:

key - The key, to be used to load the image.

Returns:

The image or null, if there is no image.

Throws:

CacheElementProviderException - in case the loading failed and nothing should or can be cached