Update Metadata From Djvu File In Java

// Edit DJVU creation date metadata
public class UpdatingMetadata
{
  public static void run() 
  {
    Date threeDaysAgo = new Date(System.currentTimeMillis() - TimeUnit.DAYS.toMillis(3));
    try (Metadata metadata = new Metadata("input.djvu"))
    {
        // Update the file creation date/time if the existing value is older than 3 days
        int affected = metadata.updateProperties(new ContainsTagSpecification(Tags.getTime().getCreated()).and(
                new OfTypeSpecification(MetadataPropertyType.DateTime)).and(
                new UpdatingMetadata().new DateBeforeSpecification(threeDaysAgo)), new PropertyValue(new Date()));

        // Process updation result
        System.out.println(String.format("Affected properties: %s", affected));

        // Save edited file
        metadata.save("output.djvu");
    }
  }

  // Define your own specifications to filter metadata properties
  public class DateBeforeSpecification extends Specification
  {
    public DateBeforeSpecification(Date date)
    {
      setValue(date);
    }

    public final Date getValue()
    {
      return auto_Value;
    }

    private void setValue(Date value)
    {
      auto_Value = value;
    }

    private Date auto_Value;

    public boolean isSatisfiedBy(MetadataProperty candidate)
    {
      Date date = candidate.getValue().toClass(Date.class);
      if (date != null)
      {
        return date.before(getValue());
      }
      return false;
    }
  }
}