Please EaseUp. There's no such thing as urgent around here.
Did you declare the column as a BLOB, or the Derby equivalent? You can then use PreparedStatement and its setBytes, setBlob or setBinaryStream methods. Retrieving is done using ResultSet's getBytes, getBlob or getBinaryStream methods.
I'll move this thread to our JDBC forum. And welcome to the Ranch!
So all you need to do is convert the hex into a byte, then convert the byte into an image. For the first you should use our search; I can clearly remember a discussion about it in Java in General. For the second you can use ImageIO.