NoSuchElementException不断被触发，我不确定为什么

Question

Basically what the aim of my program is, is to select a random quote from a text file and print it based on a random number generated that is no bigger than the number of lines in the file. I know the file is in the correct directory and contains all of the content.

I've tried using both while and for loops, but those seem to be the problem the code runs without error when the loops are not in there, but without the loops, the program doesn't do what I want it to do. Also, have tried changing the scope of certain variables.

// open file
private static void openFile(){

    try {
        input = new Scanner(Paths.get("Quotes.txt"));
    }
    catch(IOException ioException){
        System.err.println("Error opening file. Terminating.");
        System.exit(1);
    }
}

// get and print quote
private static void printQuote(){

    try {
        int printQue = randomNumber();

        System.out.println(printQue);
        for (int i = 0; i < printQue - 1; i++){
            input.nextLine();
        }

        System.out.printf("The randomly selected quote is: %s%n", 
        input.nextLine());
    }
    catch(NoSuchElementException elementException){
        System.err.println("File formed improperly. Terminating.");
    }
    catch(IllegalStateException stateException){
        System.err.println("Error reading from file. Terminating.");
    }
}

// size of list
private static int fileSize(){

    try{
        int counter = 0;
        while (input.hasNext()){
            input.nextLine();
            counter++;
        }

        num = counter;
    }
    catch(NoSuchElementException elementException){
        System.err.println("File improperly formed. Terminating");
    }
    catch(IllegalStateException stateException){
        System.err.println("Error reading from file. Terminating.");
    }

    return num;
}

// get random number
private static int randomNumber(){

    int randomNum = random.nextInt(fileSize());

    while (randomNum <= 0){
        randomNum = random.nextInt(fileSize());
    }

    return randomNum;
}

Print one of the 100 quotes in the text file.

Answer 1

Your scanner is iterating over the entire file in your fileSize() method because you're calling input.nextLine() every iteration.

Once you get to printQuote() you have already iterated over the entire file, so you're trying to read in a line at (last_index + 1).