FireBaseDatabaseManager.java

public class FireBaseDatabaseManager {

  public static FirebaseDatabase database;
  public static DatabaseReference hotelReference;

  public static FirebaseDatabase getDatabase() {
    if (database == null) {
      database = FirebaseDatabase.getInstance();
      database.setPersistenceEnabled(true);
    }
    return database;
  }

  public static DatabaseReference getHotelReference() {
    if (hotelReference == null) {
      hotelReference = getDatabase().getReference("hotels");
      hotelReference.keepSynced(true);
    }
    return hotelReference;
  }
}