import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

import java.sql.Connection;

import java.sql.ResultSet;

public class DatabaseHandler {
	private Connection dbConnection = null;
	private String computer, db_name, userName, password, url;

	DatabaseHandler() {
		computer = "atlas.dsv.su.se";
		db_name = "db_10746419";
		userName = "usr_10746419";
		password = "746419";

		try {
			dbConnection = obtainConnection(computer, db_name, userName, password);
		} catch (SQLException e) {
			e.printStackTrace();
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
	}

	public  Connection obtainConnection(String computer,
			String db_name, String userName, String password)
			throws SQLException, InstantiationException,
			IllegalAccessException, ClassNotFoundException {

		url = "jdbc:mysql://" + computer + "/" + db_name;
		Class.forName("com.mysql.jdbc.Driver").newInstance();
		return DriverManager.getConnection(url, userName, password);

	}
   public java.sql.ResultSet executeQuery(String sql){
	  Statement statement = null;
	  ResultSet resultSet = null;
	   try {
		   statement = dbConnection.createStatement();

		if(statement.execute(sql)){
			return statement.getResultSet();

		} else return null; // if query updates or inserts data.

	} catch (SQLException e) {
		e.printStackTrace();
		return null;
	}
	finally {
		if(resultSet != null)
			try {
				resultSet.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		if(statement != null)
			try {
				statement.close();
			} catch (SQLException e) {

				e.printStackTrace();
			}

	}
   }
}