getUser

public User getUser(String login){
        try {
            String sql = "select * from user where username=\'" + login + "\'";
            Statement stmt = connection.createStatement();
            ResultSet rs = stmt.executeQuery(sql);

            String username, password, email;

            rs.first();

            username = rs.getString("username");
            password = rs.getString("password");
            email = rs.getString("email");

            User user = new User(username, password, email);

            return user;
        }
        catch (SQLException ex) {
            ex.printStackTrace();
        }

        return null;
    }