Display HTML image from MySql BLOB

I store images in my MySql database as blobs using

preparedStatement.setBinaryStream(1, photo);

where photo is an InputStream.

They are correctly inserted (displayed normally in MySql workbench).

I retrieve them using

resultSet.getBytes("Photo");

and try to display them on a .jsp page like this:

<%
List<byte[]> pics = PictureTable.getConcertPictures(concertBean.getId());
%>
<%
for (byte[] p : pics) {
String encoded = ImageHelper.encodeImage(p);
String source = "data:image/jpg;base64,";
source = source.concat(encoded.toString());
%>
<img src=<%=source%>>
<%
}
%>

PictureTable.java:

public static List<byte[]> getConcertPictures(int id) {
        List<byte[]> pictures = new ArrayList<byte[]>();

        try (Connection connection = ConnectionPool.getConnectionPool().checkOut()) {

            PreparedStatement ps = connection.prepareStatement("SELECT * FROM concertphototable WHERE ConcertId=?");

            ps.setInt(1, id);

            ResultSet rs = ps.executeQuery();

            while (rs.next()) {
                pictures.add(rs.getBytes("Photo"));
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return pictures;
    }

ImageHelper.java:

public class ImageHelper {
    public static String encodeImage(byte[] img) {
        return Base64.encode(img); //com.sun.org.apache.xerces.internal.impl.dv.util.Base64
    }

but the images are not displayed.

Edit: For the sake of completeness, this is how I store the images:

<form
action="GalleryController?action=add_concert_picture&concertID=<%=concertBean.getId()%>"
method="post" class="panel panel-success"
enctype="multipart/form-data">
<div class="col-md-6 form-group">
<input type='file' name="image" class="form-control" />
</div>
<button type="submit" class="btn">Submit</button>
</form>

controller: (@MultipartConfig)

Part filePart = request.getPart("image");
InputStream fileContent = filePart.getInputStream();
PictureTable.insertConcertPicture(cid, user.getUser().getId(), fileContent);