Small Groovy script to process a pictures directory and rename them using "Date/Time original" exif field. Useful for example if you want your photos automatically sorted by their names, as if it was sorted by the photo date. My case: useful in the Ph

renameJpgWithDateTimeOrigalExif.groovy

// Using metadata-extractor-2.4.0-beta-1.jar from http://www.drewnoakes.com/drewnoakes.com/code/exif/sampleUsage.html
import com.drew.metadata.Metadata
import com.drew.imaging.jpeg.JpegMetadataReader
import com.drew.metadata.Directory
import com.drew.metadata.Tag
import java.text.*;

def dirToProcess = new File(".")
assert dirToProcess.exists()

DateFormat df = new SimpleDateFormat('yyyy-MM-dd_HHmmss')

// Note : beware that if two pics have the same time (same second) there's gonna be a problem.
// backup your photos before running !!!
dirToProcess.eachFile {jpegFile ->
	if( jpegFile.isFile() && jpegFile.getName().toLowerCase().endsWith(".jpg") )
	{
		Metadata metadata = JpegMetadataReader.readMetadata(jpegFile);
		Directory exifDirectory = metadata.getDirectory(Class.forName("com.drew.metadata.exif.ExifDirectory"));
		
		// 36867 => Date/Time Original
		int tagType = 36867
		if(exifDirectory.containsTag(tagType))
		{
			Date value = exifDirectory.getDate(36867);
			def newName = df.format(value)+".jpg"
			if(jpegFile.name != newName)
			{
				println("$jpegFile.name renamed to $newName");
				jpegFile.renameTo(new File(newName))
			}
		}
		else
		{
			println("No tagType 'Date/Time Original' for $jpegFile. Cannot rename. You'll likely have to do it by hand :-/")
		}
	}
}