ExifDataReader.java

package org.hipi.image.io;

import com.drew.imaging.ImageMetadataReader;
import com.drew.imaging.ImageProcessingException;
import com.drew.metadata.Metadata;
import com.drew.metadata.Directory;
import com.drew.metadata.Metadata;
import com.drew.metadata.Tag;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import java.util.HashMap;

/**
 * Routines for extracting EXIF data contained in a JPEG or PNG image and for flattening this type
 * of data to produce a single key/value dictionary.
 */
public class ExifDataReader {

  private class UnclosableBufferedInputStream extends BufferedInputStream {

    public UnclosableBufferedInputStream(InputStream in) {
      super(in);
    }

    @Override
    public void close() throws IOException {
    }
  }
	
  private UnclosableBufferedInputStream ubis;
  
  public ExifDataReader(InputStream is) {
    ubis = new UnclosableBufferedInputStream(is);
  }
  
  public Metadata extract() throws ImageProcessingException, IOException {
    return ImageMetadataReader.readMetadata(ubis);
  }

  public static HashMap<String,String> extractAndFlatten(InputStream is) throws IOException {
    HashMap<String,String> exifData = new HashMap<String,String>();
    try {
      ExifDataReader reader = new ExifDataReader(is);
      Metadata metadata = reader.extract();
      Iterator directories = metadata.getDirectories().iterator();
      while (directories.hasNext()) {
       Directory directory = (Directory)directories.next();
       Iterator tags = directory.getTags().iterator();
       while (tags.hasNext()) {
         Tag tag = (Tag)tags.next();
         exifData.put(tag.getTagName(), tag.getDescription());
       }
     }
   } catch (ImageProcessingException ex) {
    throw new IOException(String.format("Encountered error while attempting to extract image EXIF data [%s]", ex.getMessage()));
  }
  return exifData;
}

}