Java demo之闭环引用

Money类

public class Money {
    
    private int amount;

    public int getAmount() {
        return amount;
    }

    public void setAmount(int amount) {
        this.amount = amount;
    }
}

Boy类

public class Boy {

    public static Money money = Girl.money;

    public static Money getMoney() {
        return money;
    }

    public static void setMoney(Money money) {
        Girl.money = money;
    }
}

Girl类

public class Girl {

    public static Money money = Boy.money;

    public static Money getMoney() {
        return money;
    }

    public static void setMoney(Money money) {
        Girl.money = money;
    }
}

Start启动类

public class Start {

    public static void main(String[] args) {
        System.out.println("money is " + Boy.getMoney().getAmount());
    }

}

执行结果：编译可以通过，但会报空指针异常