Java中定时器的使用

Question

I am writing a ticket booking system for a movie theater. I want to start a timer that gives users 5 minutes to checkout after they've selected a seat. I decided to use java's Timer class.

Here is the code that starts the timer, and the expiredCheckout() function that gets called:

private void expiredCheckout() {
        Scanner inputObj = new Scanner(System.in);
        while (true) {
            System.out.println("Your session has expired!");
            System.out.println("If you want to start over, press 1"); 
            System.out.println("If you want to cancel, press q");
            String input = inputObj.next();
            System.out.println("made it here");
            if (input.equals("q"))
                return;
            else if (input.equals("1")) {
                this.runTheatreUI();
                break;
            } else {
                System.out.println("Please enter valid choice!");
            }
        }
    }

private void startTimer(ArrayList<Seat> seatsSelected) {
        Timer timer = new Timer();
        timer.schedule(
            new TimerTask() {
                public void run() {
                    expiredCheckout();
                    return;
                }
            }
            ,5*60*1000);
        ArrayList<Object> checkoutInfo = this.checkout();
        timer.cancel();
        if (checkoutInfo.get(0).equals(true)) {
            for (int i = 0; i < seatsSelected.size(); i++) {
                seatsSelected.get(i).setStatus(Seat.TAKEN);
                this.numSeatsAvailable += 1;
            }
        } else {
            // the user quit 
            for (int i = 0; i < seatsSelected.size(); i++) {
                seatsSelected.get(i).setStatus(Seat.OPEN);
                this.numSeatsAvailable += 1;
            }
        }
        return; 
    }

As you can see, I added print statements after reading input from the user. However, the function never makes it there. When I enter a character in the terminal, there is no action. I'm confused as to why that happens.

Answer 1

To cancel the timer, you can do this within the TimerTask itself

            private void expiredCheckout() {
                System.out.println("in expired method");
                Scanner inputObj = new Scanner(System.in);
                while (true) {
                    System.out.println("Your session has expired!");
                    System.out.println("If you want to start over, press 1"); 
                    System.out.println("If you want to cancel, press q");
                    String input = inputObj.nextLine();
                    System.out.println("made it here");
                    if (input.equals("q")) {
                        System.out.println("quitting");
                        timer.cancel();
                        timer.purge();
                        return;
                    }
                    else if (input.equals("1")) {
                        System.out.println("Entered 1");
                        break;
                    } else {
                        System.out.println("Please enter valid choice!");
                    }
                }                   
            }