package databaseConnection;

import java.sql.*;

/**
 * Created by pawel on 25.03.2017.
 */
abstract class DatabaseQuery {

    public static final String JDBC_URL = "jdbc:hsqldb:file:data/rozkazer.db";
    public static final String USER = "SA";
    public static final String PASSWORD = "";
    public static final String DRIVER_CLASSNAME = "org.hsqldb.jdbcDriver";
    private String sql;
    private Connection connection;
    private Statement statement;
    protected ResultSet resultSet;

    public DatabaseQuery(String sql){
        this.sql = sql;
    }

    public void execute(){
        try {
            connectToDatabase();
            executeSql();
            process();
            close();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }

    }

    private void close() throws SQLException {
        resultSet.close();
        statement.execute("SHUTDOWN");
        statement.close();
        connection.close();
    }

    abstract protected void process() throws SQLException;

    private void executeSql() throws SQLException {
        statement = connection.createStatement();
        resultSet = statement.executeQuery(sql);
    }

    private void connectToDatabase() throws ClassNotFoundException, SQLException {

        Class.forName(DRIVER_CLASSNAME);
        connection = DriverManager.getConnection(JDBC_URL, USER, PASSWORD);
    }
}