Having Trouble calling with making a non-static method

Question

I am currently working on a school project and I am suppose to be able to call for my program to call for a non-static method that would still move my current number forward and backwards. I am at a loss. What exactly should I do? Here is my coding thus far and everything works minus implementing the non-static options.

   import java.util.Scanner;

    public class PictureViewer {

    final static int MAX_NUMBER = 8;
    final static int MIN_NUMBER = 1;


    public static void main(String[] args) {
        showMenu();
    }

    public static void showMenu() {
        Scanner input = new Scanner(System.in);
        int current_number = MIN_NUMBER;
        boolean Continuation = true;
        while (Continuation) {

            System.out.println("Select One of the Options");
            System.out.println("Option 1: Forward");
            System.out.println("Option 2: Backward");
            System.out.println("Option 3: CreateFileName");
            System.out.println("Option 4: CreateRandomName");
            System.out.println("Option 5: Non-Static Forward");
            int Menu_Option = input.nextInt();
            switch (Menu_Option) {
                case 1:
                    current_number = forward(current_number);
                    System.out.println("The Current Number is: " +    current_number);
                    break;
                case 2:
                    current_number = backward(current_number);
                    System.out.println("The Current Number is: " + current_number);
                    break;
                case 3:
                    String fileName = createFileName(current_number);
                    System.out.println("File Name: " + fileName);
                    break;
                case 4:
                    fileName = createRandomName(current_number);
                    System.out.println("File Name: " + fileName);
                    break;


            }
        }
    }

    public static int forward(int current_number) {

        if (current_number >= MAX_NUMBER) {
            System.out.println(MIN_NUMBER);
            current_number = MIN_NUMBER;

        } else {
            System.out.println(current_number++);
        }
        return current_number;
    }

    public static int backward(int current_number) {

        if (current_number <= MIN_NUMBER) {
            System.out.println(current_number);
            current_number = MIN_NUMBER;
        } else current_number --; {
        }
        return current_number;
    }
    public static String createFileName(int current_number) {

        return "Picture" + current_number + ".gif";
    }

    public static String createRandomName(int current_number) {
        current_number = MIN_NUMBER + (int) (Math.random() * MAX_NUMBER);
        return "Picture" + current_number + ".gif";
    }

    public  void  forward () {
        // overloaded method, use global variable as input and output
    }

    public  void  backward () {
        // overloaded method, use global variable as input and output
    }

}

Answer 1

You don't need to make all methods static just keep only Main() static. Using this trick you will be able to access non-static methods easily and also this will save you from Critical Section problem.Follpwing are steps to implement:

1. Remove static keyword from all methods except main().
2.Replace

showOptions()

With

new PictureViewer().showOptions();

Hope this solves your problem :)

Answer 2

OK now is almost everything, please elaborate better your questions like someone willing to learn, not only " is not working", just a free advice ;-)

import java.util.Scanner;

public class PictureViewer {

final static int MAX_NUMBER = 8;
final static int MIN_NUMBER = 1;

private int currentNumber;

public static void main(String[] args) {
    showMenu();
}

public static void showMenu() {
    Scanner input = new Scanner(System.in);
    int current_number = MIN_NUMBER;
    boolean Continuation = true;
    while (Continuation) {

        System.out.println("Select One of the Options");
        System.out.println("Option 1: Forward");
        System.out.println("Option 2: Backward");
        System.out.println("Option 3: CreateFileName");
        System.out.println("Option 4: CreateRandomName");
        System.out.println("Option 5: Non-Static Forward");
        int Menu_Option = input.nextInt();
        switch (Menu_Option) {
        case 1:
            current_number = forward(current_number);
            System.out.println("The Current Number is: " + current_number);
            break;
        case 2:
            current_number = backward(current_number);
            System.out.println("The Current Number is: " + current_number);
            break;
        case 3:
            String fileName = createFileName(current_number);
            System.out.println("File Name: " + fileName);
            break;
        case 4:
            fileName = createRandomName(current_number);
            System.out.println("File Name: " + fileName);
            break;
        case 5: 
            PictureViewer pv = new PictureViewer();
            pv.setCurrentNumber(current_number);
            pv.forward();
            current_number = pv.getCurrentNumber();
            System.out.println("The Current Number is: " + current_number);
            break;
        }
    }
}

public static int forward(int current_number) {

    if (current_number >= MAX_NUMBER) {
        System.out.println(MIN_NUMBER);
        current_number = MIN_NUMBER;

    } else {
        System.out.println(current_number++);
    }
    return current_number;
}

public static int backward(int current_number) {

    if (current_number <= MIN_NUMBER) {
        System.out.println(current_number);
        current_number = MIN_NUMBER;
    } else
        current_number--;
    {
    }
    return current_number;
}

public static String createFileName(int current_number) {

    return "Picture" + current_number + ".gif";
}

public static String createRandomName(int current_number) {
    current_number = MIN_NUMBER + (int) (Math.random() * MAX_NUMBER);
    return "Picture" + current_number + ".gif";
}

public void forward() {
    // overloaded method, use global variable as input and output
    this.currentNumber = this.currentNumber +1;
}

public void backward() {
    // overloaded method, use global variable as input and output
}

public int getCurrentNumber() {
    return currentNumber;
}

public void setCurrentNumber(int currentNumber) {
    this.currentNumber = currentNumber;
}

}

Answer 3

You don't need to have all the methods defined as static in order to be called from main. You can create an object in main and call the same method. This is what I would do:

1. Make all the methods (except main) non static (i.e. remove static keyword)

2. Change main method implementation to create an object of PictureViewer class and call showMenu, e.g.

   public static void main(String[] args) { new PictureViewer().showMenu(); }