How to represent an image from database in JSON
Binary data in JSON is usually best to be represented in a Base64-encoded form. You could use the standard Java SE provided DatatypeConverter#printBase64Binary() method to Base64-encode a byte array.
byte[] imageBytes = resultSet.getBytes("image");String imageBase64 = DatatypeConverter.printBase64Binary(imageBytes);obj.put("img", imageBase64);The other side has just to Base64-decode it. E.g. in Android, you could use the builtin android.util.Base64 API for this.
byte[] imageBytes = Base64.decode(imageBase64, Base64.DEFAULT);