Java でプリミティブの参照渡しをシミュレートするにはどうすればよいですか?

class Toy {
    public int toyNumber;
}

void play(Toy toy){  
    System.out.println("Toy number in play " + toy.toyNumber);   
    toy.toyNumber++;  
    System.out.println("Toy number in play after increment " + toy.toyNumber);   
}

int play(int toyNumber){  
    System.out.println("Toy number in play " + toyNumber);   
    toyNumber++;  
    System.out.println("Toy number in play after increment " + toyNumber);   
    return toyNumber
}

void play(int[] toyNumber) {  
    System.out.println("Toy number in play" + toyNumber[0]);   
    toyNumber[0]++;  
    System.out.println("Toy number in play after increment" + toyNumber[0]);   
}