为什么在出现异常后我的代码会不断重复自身？

Question

do {

    try {
        System.out.print("Please enter the hour:");
        hour = consoleScanner.nextInt();
        if (hour < 1 || hour > 12) {
            throw new InvalidHourException();
        }

        System.out.print("Please enter the minute:");
        minute = consoleScanner.nextInt();
        if (minute < 0 || minute > 59) {
            throw new InvalidMinuteException();
        }
        if (minute <= 9)
            zero = "0";

        System.out.print("Please enter either \"AM\" or \"PM\":");
        meridiem = consoleScanner.next();
        if (!(meridiem.equalsIgnoreCase("AM"))
                && !(meridiem.equalsIgnoreCase("PM"))) {
            throw new InvalidMeridiemException();
        }

    } catch (InvalidHourException hourEx) {
        System.out.println(hourEx.getMessage());
        consoleScanner.nextLine();
        errorOccured = true;
    } catch (InvalidMinuteException minuteEx) {
        System.out.println(minuteEx.getMessage());
        consoleScanner.nextLine();
        errorOccured = true;
    } catch (InvalidMeridiemException meriEx) {
        System.out.println(meriEx.getMessage());
        consoleScanner.nextLine();
        errorOccured = true;
    }

} while (errorOccured);
System.out.println(hour + ":" + zero + minute + meridiem + " is a valid time.");
consoleScanner.close();

}
}

this is my do while loop. The output is:

Please enter the hour:8
Please enter the minute:60
Please enter a minute between 1 to 60
Please enter the hour:

why does it jump back to the hour instead of the minutes? Is there something wrong in the catch statements?

Answer 1

Since you have a single try block, and you repeat it whenever any exception is thrown, after an exception is caught, the code that prompts for the hour is executed, even if the problem wasn't with the hour input.

In order not to repeat requesting for inputs that were already valid, you'll need a separate while loop + try-catch block for each of the 3 inputs.

Beside that, you should set errorOccured to false when the input is valid. Otherwise you'll never leave the loop.