2.38.super ：调用父类的构造方法

看例程：学习 super 的使用方法

public class UsePhoneExtendsMerchandise {
    public static void main(String[] args) {

        Phone ph = new Phone();
        ph.describe();
//
//        Phone phone = new Phone(
//            "手机001", "Phone001", 100, 1999, 999,
//            4.5, 3.5, 4, 128, "索尼", "安卓"
//        );
//
//        phone.describe();
//        System.out.println();
//
//        System.out.println(phone.getName());
//        System.out.println();
//
//        phone.buy(100);
//
//        phone.buy(3);

    }
}

public class LittleSuperMarket {
    public String superMarketName;
    public String address;
    public int parkingCount;
    public double incomingSum;
    public MerchandiseV2[] merchandises;
    public int[] merchandiseSold;

    /**
     * 初始化小超市
     *
     * @param superMarketName
     * @param address
     * @param parkingCount
     * @param merchandiseCount 商品种类数
     * @param count            每种商品缺省库存
     */
    public LittleSuperMarket(String superMarketName, String address, int parkingCount,
                             int merchandiseCount, int count) {
        this.superMarketName = superMarketName;
        this.address = address;
        this.parkingCount = parkingCount;

        merchandises = new MerchandiseV2[merchandiseCount];
        for (int i = 0; i < merchandises.length; i++) {
            double purchasePrice = Math.random() * 200;
            // 创建并给商品的属性赋值
            MerchandiseV2 m = new MerchandiseV2(
                "商品" + i,
                "ID" + i,
                count,
                purchasePrice * (1 + Math.random()),
                purchasePrice
            );
            // 用创建的商品，给商品数组的第i个引用赋值，all和小超市的商品数组引用指向的是同一个数组对象
            merchandises[i] = m;
        }
        merchandiseSold = new int[merchandises.length];
    }

    // 简单的访问成员变量

    public String getSuperMarketName() {
        return superMarketName;
    }

    public String getAddress() {
        return address;
    }

    public int getParkingCount() {
        return parkingCount;
    }

    public double getIncomingSum() {
        return incomingSum;
    }

    public void setSuperMarketName(String superMarketName) {
        this.superMarketName = superMarketName;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public void setParkingCount(int parkingCount) {
        this.parkingCount = parkingCount;
    }

    public void setIncomingSum(double incomingSum) {
        this.incomingSum = incomingSum;
    }

    public void setMerchandises(MerchandiseV2[] merchandises) {
        this.merchandises = merchandises;
    }

    public void setMerchandiseSold(int[] merchandiseSold) {
        this.merchandiseSold = merchandiseSold;
    }

    // 一些特殊的逻辑

    /**
     * 得到利润最高的商品
     *
     * @return
     */
    public MerchandiseV2 getBiggestProfitMerchandise() {
        MerchandiseV2 curr = null;
        for (int i = 0; i < merchandises.length; i++) {
            MerchandiseV2 m = merchandises[i];
            // 这个逻辑有问题吗？相同的利润怎么判断？
            if (curr == null || curr.calculateProfit() < m.calculateProfit()) {
                curr = m;
            }
        }
        return curr;
    }

    /**
     * 根据索引获取商品
     *
     * @param merchandiseIndex
     * @return
     */
    public MerchandiseV2 getMerchandiseOf(int merchandiseIndex) {
        if (merchandiseIndex < 0 || merchandiseIndex >= merchandises.length) {
            return null;
        }
        return merchandises[merchandiseIndex];
    }

    /**
     * 赚钱
     *
     * @param toBeAdded
     */
    public void addIncomingSum(double toBeAdded) {
        this.incomingSum += toBeAdded;
    }

    /**
     * 花钱
     *
     * @param toBeSpent
     * @return
     */
    public boolean spendMoney(double toBeSpent) {
        if (toBeSpent > incomingSum) {
            return false;
        }
        incomingSum -= toBeSpent;
        return true;
    }

}

public class MerchandiseV2 {

    private String name;
    private String id;
    private int count;
    private double soldPrice;
    private double purchasePrice;


    public MerchandiseV2(String name, String id, int count, double soldPrice, double purchasePrice) {
        this.name = name;
        this.id = id;
        this.count = count;
        this.soldPrice = soldPrice;
        this.purchasePrice = purchasePrice;
    }

    public MerchandiseV2(String name, String id, int count, double soldPrice) {
        // double purPrice = soldPrice * 0.8;
        // this(name, id, count, soldPrice, purchasePrice);
        this(name, id, count, soldPrice, soldPrice * 0.8);
        // double purPrice = soldPrice * 0.8;
    }
//
//    public MerchandiseV2() {
//        this("无名", "000", 0, 1, 1.1);
//    }

    public void describe() {
        System.out.println("商品名字叫做" + name + "，id是" + id + "。 商品售价是" + soldPrice
            + "。商品进价是" + purchasePrice + "。商品库存量是" + count +
            "。销售一个的毛利润是" + (soldPrice - purchasePrice));
    }

    public double calculateProfit() {
        double profit = soldPrice - purchasePrice;
//        if(profit <= 0){
//            return 0;
//        }
        return profit;
    }

    public double buy(int count) {
        if (this.count < count) {
            System.out.println("购买失败，库存不够");
            return -1;
        }
        this.count -= count;
        double cost = count * soldPrice;
        System.out.println("购买成功，花费为" + cost);
        return cost;
    }


    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public int getCount() {
        return count;
    }

    public void setCount(int count) {
        this.count = count;
    }

    public double getSoldPrice() {
        return soldPrice;
    }

    public void setSoldPrice(double soldPrice) {
        this.soldPrice = soldPrice;
    }

    public double getPurchasePrice() {
        return purchasePrice;
    }

    public void setPurchasePrice(double purchasePrice) {
        this.purchasePrice = purchasePrice;
    }
}

public class Phone extends MerchandiseV2 {

    // 给Phone增加新的属性和方法
    private double screenSize;
    private double cpuHZ;
    private int memoryG;
    private int storageG;
    private String brand;
    private String os;
    private static int MAX_BUY_ONE_ORDER = 5;

    public Phone(
            String name, String id, int count, double soldPrice, double purchasePrice,
            double screenSize, double cpuHZ, int memoryG, int storageG, String brand, String os
    ) {
        // >> TODO 使用super调用父类的构造方法，必须是子类构造方法的第一个语句
        // >> TODO 可以使用表达式
        // >> TODO super调用构造方法，不可以使用super访问父类的属性和方法，不可以使用子类成员变量和方法
        // >> TODO 可以使用静态变量和方法
        // >> TODO 都是<init>方法，我们来看一下
        super(name, id, count, soldPrice * 1.2, purchasePrice);
        init(screenSize, cpuHZ, memoryG, storageG, brand, os);
    }

    public Phone() {
        super("无名", "000", 0, 1, 1.1);
        init(4.5, 4.6, 6, 128, "Uknown", "Uknown");
    }

    public void init(double screenSize, double cpuHZ, int memoryG, int storageG, String brand, String os) {
        this.screenSize = screenSize;
        this.cpuHZ = cpuHZ;
        this.memoryG = memoryG;
        this.storageG = storageG;
        this.brand = brand;
        this.os = os;
    }

    public double buy(int count) {
        if (count > MAX_BUY_ONE_ORDER) {
            System.out.println("购买失败，手机一次最多只能买" + MAX_BUY_ONE_ORDER + "个");
            return -2;
        }
        return super.buy(count);
    }

    public String getName() {
        return this.brand + ":" + this.os + ":" + super.getName();
    }

    public void describe() {
        System.out.println("此手机商品属性如下");
        super.describe();
        System.out.println("手机厂商为" + brand + "；系统为" + os + "；硬件配置如下：\n" +
                "屏幕：" + screenSize + "寸\n" +
                "cpu主频" + cpuHZ + " GHz\n" +
                "内存" + memoryG + "Gb\n" +
                "存储空间" + storageG + "Gb");
    }

    public boolean meetCondition() {
        return true;
    }

    public double getScreenSize() {
        return screenSize;
    }

    public void setScreenSize(double screenSize) {
        this.screenSize = screenSize;
    }

    public double getCpuHZ() {
        return cpuHZ;
    }

    public void setCpuHZ(double cpuHZ) {
        this.cpuHZ = cpuHZ;
    }

    public int getMemoryG() {
        return memoryG;
    }

    public void setMemoryG(int memoryG) {
        this.memoryG = memoryG;
    }

    public int getStorageG() {
        return storageG;
    }

    public void setStorageG(int storageG) {
        this.storageG = storageG;
    }

    public String getBrand() {
        return brand;
    }

    public void setBrand(String brand) {
        this.brand = brand;
    }

    public String getOs() {
        return os;
    }

    public void setOs(String os) {
        this.os = os;
    }
}

使用super调用父类的构造方法，必须是子类构造方法的第一个语句
可以使用表达式
super调用构造方法，不可以使用super访问父类的属性和方法，不可以使用子类成员变量和方法
可以使用静态变量和方法
都是方法