Class PreloaderJPEG
- java.lang.Object
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- org.apache.xmlgraphics.image.loader.impl.AbstractImagePreloader
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- org.apache.xmlgraphics.image.loader.impl.PreloaderJPEG
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- All Implemented Interfaces:
JPEGConstants
,ImagePreloader
public class PreloaderJPEG extends AbstractImagePreloader implements JPEGConstants
Image preloader for JPEG images.
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Field Summary
Fields Modifier and Type Field Description private static int[]
BYTES_PER_COMPONENT
private static int
EXIF
private static int
II
private static int
JPG_SIG_LENGTH
private static int
MM
private static int
RESOLUTION_UNIT
private static int
X_RESOLUTION
private static int
Y_RESOLUTION
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Fields inherited from interface org.apache.xmlgraphics.image.loader.spi.ImagePreloader
DEFAULT_PRIORITY
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Constructor Summary
Constructors Constructor Description PreloaderJPEG()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description private ImageSize
determineSize(javax.imageio.stream.ImageInputStream in, ImageContext context)
ImageInfo
preloadImage(java.lang.String uri, javax.xml.transform.Source src, ImageContext context)
"Preloads" an image, i.e.-
Methods inherited from class org.apache.xmlgraphics.image.loader.impl.AbstractImagePreloader
getHeader, getPriority
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Field Detail
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JPG_SIG_LENGTH
private static final int JPG_SIG_LENGTH
- See Also:
- Constant Field Values
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BYTES_PER_COMPONENT
private static final int[] BYTES_PER_COMPONENT
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EXIF
private static final int EXIF
- See Also:
- Constant Field Values
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II
private static final int II
- See Also:
- Constant Field Values
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MM
private static final int MM
- See Also:
- Constant Field Values
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X_RESOLUTION
private static final int X_RESOLUTION
- See Also:
- Constant Field Values
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Y_RESOLUTION
private static final int Y_RESOLUTION
- See Also:
- Constant Field Values
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RESOLUTION_UNIT
private static final int RESOLUTION_UNIT
- See Also:
- Constant Field Values
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Method Detail
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preloadImage
public ImageInfo preloadImage(java.lang.String uri, javax.xml.transform.Source src, ImageContext context) throws java.io.IOException, ImageException
"Preloads" an image, i.e. indentifies whether the source image is supported by this implementation and determines the image's intrinsic size and possibly some additional information. The image is usually not fully loaded at this time to conserve memory. The method returns null if the image was not identified. AnImageException
is only thrown if the image is identified but some error has happened while working on the file.- Specified by:
preloadImage
in interfaceImagePreloader
- Parameters:
uri
- the original (unresolved) URI of the imagesrc
- a image source the image is loaded fromcontext
- the context object that provides configuration information- Returns:
- an image info object with the basic information about an image or null if the image is not supported by this implementation
- Throws:
ImageException
java.io.IOException
- if an I/O error occurs while preloading the image
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determineSize
private ImageSize determineSize(javax.imageio.stream.ImageInputStream in, ImageContext context) throws java.io.IOException, ImageException
- Throws:
java.io.IOException
ImageException
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