import java.sql.*;

public class DBConnector {

	Connection conn = null;

	public DBConnector(String DBName, String username, String password) {

		try {
			String url = "jdbc:mysql://localhost/" + DBName;
			Class.forName("com.mysql.jdbc.Driver").newInstance();
			conn = DriverManager.getConnection(url, username, password);
			System.out.println("Database connection established");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public DBConnector(String host, String DBName, String username, String password) {

		try {
			String url = "jdbc:mysql://"+host+"/";
			Class.forName("com.mysql.jdbc.Driver").newInstance();
			conn = DriverManager.getConnection(url, username, password);
			System.out.println("Database connection established");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}


	public void update(String query) throws SQLException {
		Statement s;

			s = conn.createStatement();
			s.executeUpdate(query);
			s.close();
	}

	public ResultSet query(String query) {
		try {
			Statement s = conn.createStatement();
			s.executeQuery(query);
			ResultSet rs = s.getResultSet();
			s.close();
			return rs;
		} catch (Exception k) {
			k.printStackTrace();
			return null;
		}
	}

	public void closeConnection() {
		try {
			conn.close();
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

}