public interface IUser {
    ArrayList<UserBean> getUsers() throws SQLException;
}

public class User implements IUser {

    private DataSource dataSource;

    public User() {
        dataSource = Connection.getDataSource();
    }

    @Override
    public ArrayList<UserBean> getUsers() throws SQLException {
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;
        ArrayList<UserBean> userBeans = new ArrayList<>();
        try (Connection connection = dataSource.getConnection()) {
            preparedStatement = connection.prepareStatement("SELECT user.id, user.emailAddress FROM user");
            resultSet = preparedStatement.executeQuery();

            while(resultSet.next()) {
                UserBean userBean = new UserBean(resultSet.getInt("user.id"), resultSet.getString("user.emailAddress"));
                userBeans.add(userBean);
            }
        } finally {
            if(preparedStatement != null) preparedStatement.close();
            if(resultSet != null) resultSet.close();
        }
        return userBeans;
    }
}

public class UserBean implements Serializable {

    private int id;
    private String emailAddress;

    public UserBean(int id, String emailAddress) {
        this.id = id;
        this.emailAddress = emailAddress;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getEmailAddress() {
        return emailAddress;
    }

    public void setEmailAddress(String emailAddress) {
        this.emailAddress = emailAddress;
    }

}

public class Connection {

    private static MysqlDataSource dataSource;

    public synchronized static MysqlDataSource getDataSource() {
        if (dataSource != null) return dataSource;

        dataSource = new MysqlDataSource();
        if(System.getenv("DEVELOPMENT") != null) {
            dataSource.setURL("jdbc:mysql://localhost:3306/Sales?authReconnect=true&useSSL=false&allowMultiQueries=true&useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC");
            dataSource.setUser("root");
            dataSource.setPassword("pass1");
        } else {
            dataSource.setURL("jdbc:mysql://foo.bar.rds.example.com:3306/Entitlement?authReconnect=true&useSSL=false&allowMultiQueries=true");
            dataSource.setUser("root");
            dataSource.setPassword("pass2");
        }

        return dataSource;
    }

}