I have multiple entities like Hotels, Destination Cities etc which can contain images. The way I have my system setup right now is, I think of all the images belonging to this universal set (a table in the DB contains filePaths to all the images).

When I have to add an image to an entity, I see if the entity exists in this universal set of images. If it exists, attach the reference to this image, else create a new image. E.g.:

class ImageEntityHibernateDAO {
        public void addImageToEntity(IContainImage entity, String filePath,
                String title, String altText) {
            ImageEntity image = this.getImage(filePath);

            if (image == null)
                image = new ImageEntity(filePath, title, altText);

            getSession().beginTransaction();
                entity.getImages().add(image);
            getSession().getTransaction().commit();

        }
}

My question is: Earlier I had to write this code for each entity (and each entity would have a Set collection). So, instead of re-writing the same code, I created the following interface:

public interface IContainImage {
    Set<ImageEntity> getImages();
}

Entities which have image collections also implements IContainImage interface. Now, for any entity that needs to support adding Image functionality, all I have to invoke from the DAO looks something like this:

// in DestinationDAO::addImageToDestination {
imageDao.addImageToEntity(destination, imageFileName, imageTitle, imageAltText);

// in HotelDAO::addImageToHotel {
imageDao.addImageToEntity(hotel, imageFileName, imageTitle, imageAltText);

It'd be great help if someone can provide me some critique on this design ? Are there any serious flaws that I'm not seeing right away ?