@Singleton
public class LoginDAO implements ILoginDAO {

    private Map<String, String> userPasswords = new HashMap<>();

    @Inject
    IDatabase database;

    @Override
    public String getUserPassword(String username){
        if(getPassword(username)!= null){
            return getPassword(username);
        }
        try{
            Connection connection = database.getConnection();
            PreparedStatement ps = connection.prepareStatement("SELECT * FROM Login WHERE username = ?");
            System.out.println("Im being called again :D");
            ps.setString(1, username);
            ResultSet rs = ps.executeQuery();
            String password = rs.next() ? rs.getString("password") : "";
            ps.close();
            addPassword(username, password);
            return password;
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }

    private String getPassword(String username){
        if(userPasswords.get(username) != null){
            return userPasswords.get(username);
        }
        return null;
    }

    private void addPassword(String username, String password){
        if(getPassword(username) == null){
            userPasswords.put(username, password);
        }
    }

}