org.apache.wicket.markup.html.image.resource
Class BlobImageResource

java.lang.Object
  extended by org.apache.wicket.request.resource.AbstractResource
      extended by org.apache.wicket.request.resource.DynamicImageResource
          extended by org.apache.wicket.markup.html.image.resource.BlobImageResource
All Implemented Interfaces:
java.io.Serializable, IClusterable, IResource

public abstract class BlobImageResource
extends DynamicImageResource

An ImageResource subclass for dynamic images that come from database BLOB fields. Subclasses override getBlob() to provide the image data to send back to the user. A given subclass may decide how to produce this data and whether/how to buffer it.

Author:
Eelco Hillenius
See Also:
Serialized Form

Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.wicket.request.resource.AbstractResource
AbstractResource.ResourceResponse, AbstractResource.WriteCallback
 
Nested classes/interfaces inherited from interface org.apache.wicket.request.resource.IResource
IResource.Attributes
 
Field Summary
 
Fields inherited from class org.apache.wicket.request.resource.AbstractResource
INTERNAL_HEADERS
 
Constructor Summary
BlobImageResource()
          Construct.
BlobImageResource(java.lang.String format)
          Construct.
 
Method Summary
protected abstract  java.sql.Blob getBlob()
          Gets the BLOB (Binary Large OBject) that holds the raw image data.
protected  byte[] getImageData(IResource.Attributes attributes)
          Get image data for our dynamic image resource.
 
Methods inherited from class org.apache.wicket.request.resource.DynamicImageResource
configureResponse, getFormat, newResourceResponse, setFormat, setLastModifiedTime, toImageData
 
Methods inherited from class org.apache.wicket.request.resource.AbstractResource
configureCache, getCachingStrategy, respond, setResponseHeaders
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

BlobImageResource

public BlobImageResource(java.lang.String format)
Construct.

Parameters:
format -

BlobImageResource

public BlobImageResource()
Construct.

Method Detail

getImageData

protected byte[] getImageData(IResource.Attributes attributes)
Description copied from class: DynamicImageResource
Get image data for our dynamic image resource. If the subclass regenerates the data, it should set the DynamicImageResource.setLastModifiedTime(Time) when it does so. This ensures that image caching works correctly.

Specified by:
getImageData in class DynamicImageResource
Parameters:
attributes - the context bringing the request, response and the parameters
Returns:
The image data for this dynamic image. null means there is no image and 404 (Not found) response will be return.

getBlob

protected abstract java.sql.Blob getBlob()
Gets the BLOB (Binary Large OBject) that holds the raw image data.

Returns:
the BLOB


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