use getter to pass value failed in java

I am a beginner there are two classes that I want to use getter to pass the value of the field from another class. Therefore, I did something like this How do getters and setters work?

But it didn’t pass the value. I got IllegalArgumentException: bound must be greater than origin from the NimAIPlayer since its bound and origin can’t be the same value. What could be the reason?

Here is part of the NimAIPlayer class

public class NimAIPlayer extends NimPlayer implements Testable {

NimGame nimGame = new NimGame();
private int stoneTaken;


public int moveStone() {
    int balance = nimGame.getStoneBalance();
    int initialStone = nimGame.getInitialStone();
    int upperBound = nimGame.getUpperBound();
    if (initialStone == balance) {
        stoneTaken = ThreadLocalRandom.current().nextInt(1, upperBound + 1);
        return stoneTaken;

    } else if (balance < upperBound){
        stoneTaken = ThreadLocalRandom.current().nextInt(1,  + balance + 1);
        return stoneTaken;

    } else if (balance >= upperBound){
        stoneTaken = ThreadLocalRandom.current().nextInt(1, upperBound + 1);
        return stoneTaken;
    }
    return -1;
}

And here is part of my NimGame class

public class NimGame extends Nimsys {

NimPlayer player1;
NimPlayer player2;

int stars;
int stoneBalance;
int initialStone;
int upperBound;
int takeStone;

public NimGame() {

}

public NimGame(NimModel nimModel, int initialStone, int upperBound , NimPlayer player1, NimPlayer player2) {
    this.initialStone = initialStone;
    this.upperBound = upperBound;
    this.player1 = player1;
    this.player2 = player2;
}

public int getInitialStone() {
    return initialStone;
}

public int getUpperBound() {
    return upperBound;
}

public int getStoneBalance() {
    return stoneBalance;
}

Any help is highly appreciated.

Answer

Add a parameterized constructor in NimGame class

NimGame.java

public NimGame(NimModel nimModel, int initialStone, int upperBound , NimPlayer player1, NimPlayer player2 , int stoneBalance) {
            this.initialStone = initialStone;
            this.upperBound = upperBound;
            this.player1 = player1;
            this.player2 = player2;
            this.stoneBalance = stoneBalance;

        }

NimAIPlayer.java

You can initialize NimGame object like this using parameterized constructor

NimGame nimGame = new NimGame(new NimModel(),10,15,new NimPlayer(),new NimPlayer(),8);

Using NimGame nimGame = new NimGame() will initialize all fields with default values like null for object type and 0 for int type . This will result getting 0 for all interger fields when you print inside moveStone method .