I’m interested in parsing multiple segments of a JPG file. Using apache-commons-imaging (that is the library I am working with – please do not suggest other libraries), this is the code I came up with (MWE):

package org.test.exiftest;

import org.apache.commons.imaging.Imaging;
import org.apache.commons.imaging.ImagingException;
import org.apache.commons.imaging.bytesource.ByteSource;
import org.apache.commons.imaging.common.ImageMetadata;
import org.apache.commons.imaging.formats.jpeg.JpegImageMetadata;
import org.apache.commons.imaging.formats.jpeg.JpegImageParser;
import org.apache.commons.imaging.formats.jpeg.segments.GenericSegment;
import org.apache.commons.imaging.formats.tiff.TiffImageMetadata;

import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;

public class Main {

    public static void main(String[] args) {
        final Path src = Path.of("your_file.JPG");

        parseExif(src);
        parseSegments(src);
    }

    private static void parseExif(Path src) {

        try (final InputStream is = Files.newInputStream(src)) {
            ImageMetadata meta = Imaging.getMetadata(is, "testfile");
            var parsedExif = ((JpegImageMetadata)(meta)).getExif();

        } catch (final IOException e) {
            System.out.println("Erraror: " + e.getMessage());
        }
    }

    private static void parseSegments(Path src) {

        try (final InputStream is = Files.newInputStream(src)) {
            ByteSource bs = ByteSource.inputStream(is, "testfile");
            JpegImageParser parser = new JpegImageParser();
            var segments = parser.readSegments(bs, null, false);

            for (var s : segments) {
                System.out.println(s.getDescription());
            }

            var rawExif = ((GenericSegment)segments.getFirst()).getSegmentData();

        } catch (final IOException e) {
            System.out.println("Error: " + e.getMessage());
        }

    }
}

So I can easily get to the parsed exif data via Imaging.getMetadata(), but this method does not return all the information about the image I want.

I would like to extract all required information from the segments themselves. However, while I can get the raw bytes for the APP1 segment (see above), I wasn’t able to find any support in the commons-imaging library to construct a TiffImageMetadata object or something similar from those raw bytes to use the library methods to work with the exif data.

I can parse the image twice, as shown above. That works. But maybe there is a more elegant solution? Thanks.