Upload de imagem usando Hibernate dentro do PostgreSQL

    BASE64Encoder base64Encoder = new BASE64Encoder();
    StringBuilder imageString = new StringBuilder();
    imageString.append("data:image/png;base64,");
    imageString.append(base64Encoder.encode(bytes)); //bytes will be image byte[] come from DB 
    String image = imageString.toString();
    modelView.put("imagetoDisplay",image);// put in your model object for using in your JSP

  <img src="${imagetoDisplay}" width="100" height="100"/>