How do I run both a Scanner and another function?

Question

I am making a game where you have a "Dillo", and it will slowly lose weight over time with the hunger function. However, the player can enter in a number whenever that will "add" weight to it. If the weight goes too high, the dillo dies. If the dillo's health goes too low, then it dies as well. The problem comes when I'm trying to get the scanner to listen, while also allowing the "hunger" function to tick down its health. However, when it gets to the "input.nextInt()" line, it will stop until it gets a number.

import java.util.Scanner;

public class Main {

    static Scanner input = new Scanner(System.in);
    public static Dillo arma = new Dillo("Arma", 50, false);

    public static void main(String[] args) {

        while (true) {
            arma.stats();
            arma.hunger();
            int food = input.nextInt();
            arma.feed(food);
            arma.dead();
        }
    }
}
public class Dillo {
    private double weight;
    private boolean isDead;
    private String name;

    public Dillo(String name, double weight, boolean isDead) {
        this.name = name;
        this.weight = weight;
        this.isDead = isDead;
    }

    public double getWeight() {
        return this.weight;
    }
    public void setWeight(double weight) {
        this.weight = weight;
    }

    public void stats() {
        System.out.println(name + " is " + weight + " pounds!");
    }

    public void feed(int foodAmnt) {
        this.weight += foodAmnt;
        System.out.println(name + " has grown by " + foodAmnt + " pounds!");
        System.out.println(name + " is now " + weight + " pounds!");
    }

    public void dead() {
        if (this.weight >= 75) {
            isDead = true;
            System.out.println(this.name + " is too fat and died!");
            System.exit(0);
        } else if (this.weight <= 25) {
            isDead = true;
            System.out.println(this.name + " is too skinny and died!");
            System.exit(0);
        }
    }

    public void hunger() {
        this.weight -= 1;
        System.out.println(this.weight);
    }

}

Answer 1

Look at this,I have modified your code with using multithread and it now can run as what you think .

---

Here is the code:

 package exercise.dillo;

import java.util.Random;
import java.util.Scanner;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class Main {

    static Scanner input = new Scanner(System.in);
    public static Dillo arma = new Dillo("Arma", 50, false);

    public static void main(String[] args) {
        ExecutorService exec = Executors.newSingleThreadExecutor();
        exec.execute(new DilloTask(arma));
        while (true) {
            // arma.stats();
            // arma.hunger();
            int food = input.nextInt();
            arma.feed(food);
            // arma.dead();
        }
    }
}

class DilloTask implements Runnable {
    private Dillo dillo;
    private Random rand = new Random();

    public DilloTask(Dillo dillo) {
        this.dillo = dillo;
    }

    @Override
    public void run() {
        try {
            while (!Thread.interrupted()) {
                TimeUnit.MILLISECONDS.sleep(1000 + rand.nextInt(1000));
                dillo.stats();
                dillo.hunger();
                dillo.dead();
            }
        } catch (InterruptedException e) {
            System.out.println("DilloTask is interrupted");
        }

    }

}

And the Dillo class,just make a few changes with synchronized keyword.

   package exercise.dillo;

public class Dillo {
    private double weight;
    private boolean isDead;
    private String name;

    public Dillo(String name, double weight, boolean isDead) {
        this.name = name;
        this.weight = weight;
        this.isDead = isDead;
    }

    public double getWeight() {
        return this.weight;
    }
    public void setWeight(double weight) {
        this.weight = weight;
    }

    public synchronized void  stats() {
        System.out.println(name + " is " + weight + " pounds!");
    }

    public synchronized void feed(int foodAmnt) {
        this.weight += foodAmnt;
        System.out.println(name + " has grown by " + foodAmnt + " pounds!");
        System.out.println(name + " is now " + weight + " pounds!");
    }

    public synchronized void dead() {
        if (this.weight >= 75) {
            isDead = true;
            System.out.println(this.name + " is too fat and died!");
            System.exit(0);
        } else if (this.weight <= 25) {
            isDead = true;
            System.out.println(this.name + " is too skinny and died!");
            System.exit(0);
        }
    }

    public synchronized void hunger() {
        this.weight -= 1;
        System.out.println(this.weight);
    }

}

Now the result is like this:

Arma is 50.0 pounds!
49.0
Arma is 49.0 pounds!
48.0
Arma is 48.0 pounds!
47.0
Arma is 47.0 pounds!
46.0
10Arma is 46.0 pounds!
45.0

Arma has grown by 10 pounds!
Arma is now 55.0 pounds!
Arma is 55.0 pounds!
54.0
....
    Arma is 37.0 pounds!
36.0
-2
Arma has grown by -2 pounds!
Arma is now 34.0 pounds!
Arma is 34.0 pounds!
33.0
-Arma is 33.0 pounds!
32.0
3
Arma has grown by -3 pounds!
Arma is now 29.0 pounds!
Arma is 29.0 pounds!
28.0
Arma is 28.0 pounds!
27.0
Arma is 27.0 pounds!
26.0
Arma is 26.0 pounds!
25.0
Arma is too skinny and died!

I use the Random class to make the hungry time indefinitely.You can cancel it or reset the hungry time.This example use two threads,one is the main thread and the other one run the DilloTask,so when you input a number will not block procedure.