public class Database {
private static Database db;
private Connection con;

public static Database getDB() throws Exception{
    if(db == null)
        db = new Database();
    return db;
}

private Database() throws Exception{
Class.forName("com.mysql.jdbc.Driver");
String connectionUrl = "jdbc:mysql://localhost:3306/psoftware?user=sdUsers"
                    +"&password=sistemeD";
  con = DriverManager.getConnection(connectionUrl);
}

public ResultSet executeQuery(String query) throws Exception{
    Statement stmt = con.createStatement();
    return stmt.executeQuery(query);
}

public PreparedStatement prepareStatement(String query) throws Exception{
    return con.prepareStatement(query);
}
}