Java I/O

Iam really working for two days cannot find any solutuin for this
When i use input methods to write into a file ,it write like in the image, I cannot read it back using scanner or different methods, My main goal is to store integers into a file then i can get it back. put in mind i want to use loops to read all the integers that stored the file
so please if you could help me.

public class queueMachine extends ATM {

   
   
    public static void main(String[] args) throws InterruptedException {
        orderMe();
    }
    
    static void orderMe() throws InterruptedException {
        
        System.out.println("\nPress 1 to enter the queue of the ATM\nPress 2 for more details\n");
        int queueMachine = scanner.nextInt();
        switch(queueMachine){
        case 1: addToQueue();
        break;
        case 2: queueMachineDetails();
        break;
        }
    }
    
    static void addToQueue() throws InterruptedException {
        back++;
        mainQueue.add(back);
        queueMachOrder++;

        System.out.println("Your number is: "+ back);
        int customersBeforeYou = mainQueue.size() -1;
        System.out.println("Number of Customers before you: " + customersBeforeYou);
        Thread.sleep(1000);
        orderMe();
    }
    
    static void removeFromQueue() {
        System.out.println("Queue removed");
        front++;
        mainQueue.poll();
        System.out.println("reamining customers: "+ mainQueue.size());
    }
    
    static void queueMachineDetails() throws InterruptedException {
        System.out.println("\n\nThis is the Queue Machine\nIf you want to use our ATM");
        orderMe();
    }

    public static int getFront() {
        return front;
    }

    public static void setFront(int front) {
        queueMachine.front = front;
    }

    public static int getBack() {
        return back;
    }

    public static void setBack(int back) {
        queueMachine.back = back;
    }
    
    
}

java