Package com.drew.metadata.exif

Class ExifReader

java.lang.Object

com.drew.metadata.exif.ExifReader

All Implemented Interfaces:

JpegSegmentMetadataReader

public class ExifReader
extends Object
implements JpegSegmentMetadataReader

Decodes Exif binary data, populating a Metadata object with tag values in ExifSubIFDDirectory, ExifThumbnailDirectory, ExifInteropDirectory, GpsDirectory and one of the many camera makernote directories.

Author:

Drew Noakes https://drewnoakes.com

Field Summary

Fields

Modifier and Type	Field	Description
static final String	JPEG_SEGMENT_PREAMBLE	Exif data stored in JPEG files' APP1 segment are preceded by this six character preamble "Exif\0\0".

Constructor Summary

Constructors

Constructor	Description
ExifReader()

Method Summary

Modifier and Type	Method	Description
void	extract(RandomAccessReader reader, Metadata metadata)	Reads TIFF formatted Exif data from start of the specified RandomAccessReader.
void	extract(RandomAccessReader reader, Metadata metadata, int readerOffset)	Reads TIFF formatted Exif data a specified offset within a RandomAccessReader.
void	extract(RandomAccessReader reader, Metadata metadata, int readerOffset, Directory parentDirectory)	Reads TIFF formatted Exif data at a specified offset within a RandomAccessReader.
Iterable<JpegSegmentType>	getSegmentTypes()	Gets the set of JPEG segment types that this reader is interested in.
void	readJpegSegments(Iterable<byte[]> segments, Metadata metadata, JpegSegmentType segmentType)	Extracts metadata from all instances of a particular JPEG segment type.
static boolean	startsWithJpegExifPreamble(byte[] bytes)	Indicates whether 'bytes' starts with 'JpegSegmentPreamble'.

Methods inherited from class java.lang.Object

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

Field Details

JPEG_SEGMENT_PREAMBLE

public static final String JPEG_SEGMENT_PREAMBLE

Exif data stored in JPEG files' APP1 segment are preceded by this six character preamble "Exif\0\0".

See Also:

• Constant Field Values

Constructor Details

ExifReader

public ExifReader()

Method Details

getSegmentTypes

public Iterable<JpegSegmentType> getSegmentTypes()

Description copied from interface: JpegSegmentMetadataReader

Gets the set of JPEG segment types that this reader is interested in.

Specified by:

getSegmentTypes in interface JpegSegmentMetadataReader

readJpegSegments

public void readJpegSegments(Iterable<byte[]> segments,
 Metadata metadata,
 JpegSegmentType segmentType)

Description copied from interface: JpegSegmentMetadataReader

Extracts metadata from all instances of a particular JPEG segment type.

Specified by:

readJpegSegments in interface JpegSegmentMetadataReader

Parameters:

segments - A sequence of byte arrays from which the metadata should be extracted. These are in the order encountered in the original file.

metadata - The Metadata object into which extracted values should be merged.

segmentType - The JpegSegmentType being read.

startsWithJpegExifPreamble

public static boolean startsWithJpegExifPreamble(byte[] bytes)

Indicates whether 'bytes' starts with 'JpegSegmentPreamble'.

extract

public void extract(RandomAccessReader reader,
 Metadata metadata)

Reads TIFF formatted Exif data from start of the specified RandomAccessReader.

extract

public void extract(RandomAccessReader reader,
 Metadata metadata,
 int readerOffset)

Reads TIFF formatted Exif data a specified offset within a RandomAccessReader.

extract

public void extract(RandomAccessReader reader,
 Metadata metadata,
 int readerOffset,
 Directory parentDirectory)

Reads TIFF formatted Exif data at a specified offset within a RandomAccessReader.