org.apache.cocoon.reading
Class ImageReader

java.lang.Object
  org.apache.avalon.framework.logger.AbstractLogEnabled
      org.apache.cocoon.reading.AbstractReader
          org.apache.cocoon.reading.ResourceReader
              org.apache.cocoon.reading.ImageReader

All Implemented Interfaces:

Poolable, Recyclable, Component, Configurable, LogEnabled, CacheableProcessingComponent, Reader, SitemapModelComponent, SitemapOutputComponent

public final class ImageReader
extends ResourceReader

The ImageReader component is used to serve binary image data in a sitemap pipeline. It makes use of HTTP Headers to determine if the requested resource should be written to the OutputStream or if it can signal that it hasn't changed. Parameters:

<width>

This parameter is optional. When specified, it determines the width of the binary image. If no height parameter is specified, the aspect ratio of the image is kept. The parameter may be expressed as an int or a percentage.

<height>

This parameter is optional. When specified, it determines the height of the binary image. If no width parameter is specified, the aspect ratio of the image is kept. The parameter may be expressed as an int or a percentage.

<scale(Red|Green|Blue)>

This parameter is optional. When specified it will cause the specified color component in the image to be multiplied by the specified floating point value.

<offset(Red|Green|Blue)>

This parameter is optional. When specified it will cause the specified color component in the image to be incremented by the specified floating point value.

<grayscale>

This parameter is optional. When specified and set to true it will cause each image pixel to be normalized. Default is "false".

<allow-enlarging>

This parameter is optional. By default, if the image is smaller than the specified width and height, the image will be enlarged. In some circumstances this behaviour is undesirable, and can be switched off by setting this parameter to "false" so that images will be reduced in size, but not enlarged. The default is "true".

<quality>

This parameter is optional. By default, the quality uses the default for the JVM. If it is specified, the proper JPEG quality compression is used. The range is 0.0 to 1.0, if specified.

Version:

$Id: ImageReader.html 1304258 2012-03-23 10:09:27Z ilgrosso $

Field Summary

Fields inherited from class org.apache.cocoon.reading.ResourceReader

bufferSize, byteRanges, configuredBufferSize, configuredByteRanges, configuredExpires, configuredQuickTest, expires, inputSource, quickTest, request, response

Fields inherited from class org.apache.cocoon.reading.AbstractReader

objectModel, out, parameters, resolver, source

Fields inherited from interface org.apache.cocoon.reading.Reader

ROLE

Constructor Summary

ImageReader()

Method Summary

Serializable	getKey() Generate the unique key.
protected void	processStream(InputStream inputStream)
protected byte[]	readFully(InputStream in)
void	recycle() Recyclable
void	setup(SourceResolver resolver, Map objectModel, String src, Parameters par) Setup the reader.
protected void	setupHeaders() Setup the response headers: Accept-Ranges, Expires

Methods inherited from class org.apache.cocoon.reading.ResourceReader

configure, generate, getLastModified, getMimeType, getValidity, hasRanges, parameterize

Methods inherited from class org.apache.cocoon.reading.AbstractReader

setOutputStream, shouldSetContentLength

Methods inherited from class org.apache.avalon.framework.logger.AbstractLogEnabled

enableLogging, getLogger, setupLogger, setupLogger, setupLogger

Methods inherited from class java.lang.Object

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

Constructor Detail

ImageReader

public ImageReader()

Method Detail

setup

public void setup(SourceResolver resolver,
                  Map objectModel,
                  String src,
                  Parameters par)
           throws ProcessingException,
                  SAXException,
                  IOException

Description copied from class: ResourceReader

Setup the reader. The resource is opened to get an InputStream, the length and the last modification date

Specified by:

setup in interface SitemapModelComponent

Overrides:

setup in class ResourceReader

Throws:

ProcessingException

SAXException

IOException

setupHeaders

protected void setupHeaders()

Description copied from class: ResourceReader

Setup the response headers: Accept-Ranges, Expires

Overrides:

setupHeaders in class ResourceReader

readFully

protected byte[] readFully(InputStream in)
                    throws IOException

Throws:

IOException

processStream

protected void processStream(InputStream inputStream)
                      throws IOException,
                             ProcessingException

Overrides:

processStream in class ResourceReader

Throws:

IOException

ProcessingException

getKey

public Serializable getKey()

Generate the unique key. This key must be unique inside the space of this component.

Specified by:

getKey in interface CacheableProcessingComponent

Overrides:

getKey in class ResourceReader

Returns:

The generated key consists of the src and width and height, and the color transform parameters

recycle

public void recycle()

Description copied from class: ResourceReader

Recyclable

Specified by:

recycle in interface Recyclable

Overrides:

recycle in class ResourceReader