关于java子类继承父类的方法的细节有关问题_J2SE

关于java子类继承父类的方法的细节问题
类DiscountedItem extends 类Item。

类Item的内容：

Java code

public class Item {    double price;    String name;    public Item(String name, double price) {        this.price = price;        this.name = name;    }    public Item() {}}

类DiscountedItem的内容：

Java code

public class DiscountedItem extends Item {    String name;    double price;    int bulkQuen;    double bulkPri;        public DiscountedItem(String name, double price, int bulkQuen, double bulkPri) {        this.name = name;        this.price = price;        this.bulkQuen = bulkQuen;        this.bulkPri = bulkPri;    }}

purchase类的内容：

Java code

public class Purchase {    Item item;    int quantity;    public Purchase(Item item, int quantity) {        this.item = item;        this.quantity = quantity;    }    public double getPrice() {        return quantity * item.price;    }    public static void main(String[] args) {        DiscountedItem di = new DiscountedItem("apple", 10, 20, 7);        Purchase p = new Purchase(di, 10);        System.out.println(p.getPrice());    }}

运行purchase的打印结果为0。而我期望的是结果是100（即10快 * 10个 = 100块钱）。
如何改Purchase类的getPrice()方法才能正确显示价格。

------解决方案--------------------

Java code

public class DiscountedItem extends Item {    int bulkQuen;    double bulkPri;        public DiscountedItem(String name, double price, int bulkQuen, double bulkPri) {        super(name,price);        this.bulkQuen = bulkQuen;        this.bulkPri = bulkPri;    }}
------解决方案--------------------
楼上正解。你用的变量时子类里面的，而父类的变量被你覆盖掉了。
------解决方案--------------------
也可以把Java code        return quantity * item.price;