hasmap

                     // tmp hash map for single contact
                        HashMap<String, String> contact = new HashMap<>();
                        // adding each child node to HashMap key => value
                        contact.put("id_limbah", id);
                        contact.put("tanggal", tgl);
                        contact.put("volume", vol);
                        contact.put("bau", bau);
                        contact.put("keruh", keruh);

                        // adding contact to contact list
                        dataList.add(contact);
                    }