java学习之路 之 高级类特性-抽象类-练习题

/**
    具体类 : 对现实世界事物的抽象定义
    抽象类 : 对某一类型的不同种事物的抽象定义
*/
//编写抽象类Pet, 属性:名字,年龄,体重;  抽象方法speak,eat
public abstract class Pet {

    // 可以包含属性, 构造器,普通方法, 抽象方法
    private String name;
    private int age;
    private double weight;

    public Pet() {}

    public Pet(String name,int age,double weight) {
        this.name = name;
        this.age = age;
        this.weight = weight;
    }

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

    public String getName() {
        return name;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public int getAge() {
        return age;
    }

    public void setWeight(double weight) {
        this.weight = weight;
    }

    public double getWeight() {
        return weight;
    }
    // 抽象方法 : 只有方法签名没有方法体, 被abstract修饰
    public abstract void speak();//抽象方法

    public abstract void eat();//抽象方法

    @Override 
    public String toString() {
        return "姓名:" + name + ",年龄:" + age + ",体重:" + weight + "Kg";
    }
}

//编写Bird类继承Pet,特有属性:flySpeed
public class Bird extends Pet {

    private int flySpeed;

    public Bird() {}

    public Bird(String name,int age,double weight,int flySpeed) {
        super(name,age,weight);
        this.flySpeed = flySpeed;
    }

    public void setFlySpeed(int flySpeed) {
        this.flySpeed = flySpeed;
    }

    public int getFlySpeed() {
        return flySpeed;
    }
    // 方法实现!! 去掉abstract 加上方法体
    // 具体子类重写并加上方法体抽象父类的抽象方法
    @Override
    public void speak() {
        System.out.println("叽叽喳喳的叫个不停!!!!");
    }
    @Override
    public void eat() {
        System.out.println("最喜欢吃虫子!!!!正在吃虫子中......");
    }
    @Override 
    public String toString() {//父类中toString方法重写
        return super.toString() + ",飞行速度:" + flySpeed + "Km/小时!!!";
    }
}

//编写Cat类继承Pet,特有属性:颜色
public class Cat extends Pet {

    private String color;

    public Cat() {}

    public Cat(String name,int age,double weight,String color) {
        super(name,age,weight);
        this.color = color;
    }

    public void setColor(String color) {
        this.color = color;
    }

    public String getColor() {
        return color;
    } 
    @Override
    public void speak() {//
        System.out.println("喵喵喵的叫个不停!!!!");
    }
    @Override
    public void eat() {//
        System.out.println("最喜欢鱼!!!!正在吃鱼中......");
    }
    @Override 
    public String toString() {//父类中toString方法重写
        return super.toString() + ",颜色:" + color;
    }
}

//编写Dog类继承Pet,特有属性:品种
public class Dog extends Pet {

    private String variety; 

    public Dog() {}

    public Dog(String name,int age,double weight,String variety) {
        super(name,age,weight);
        this.variety = variety;
    }

    public void setVariety(String variety) {
        this.variety = variety;
    }

    public String getVariety() {
        return variety;
    }
    @Override
    public void speak() {
        System.out.println("汪汪汪的叫个不停!!!!");
    }
    @Override
    public void eat() {
        System.out.println("最喜欢骨头!!!!正在吃骨头中......");
    }
    @Override 
    public String toString() {//父类中toString方法重写
        return super.toString() + ",品种:" + variety;
    }
}
/*
创建6个元素的数组，分别存放2个Cat、2个Dog和2个Bird对象
将数组元素按重量倒序排序，然后打印各对象的字符串表示（toString）
*/
class PetTest {

    public static void main(String[] args) {
        //创建6个元素的数组，分别存放2个Cat、2个Dog和2个Bird对象
        Pet[] ps = new Pet[6];
        //public Cat(String name,int age,double weight,String color)
        ps[0] = new Cat("小咪",2,2.5,"黑色");
        ps[1] = new Cat("二咪",3,3.5,"白色");
        //public Dog(String name,int age,double weight,String variety)
        ps[2] = new Dog("大汪",3,5.5,"泰迪");
        ps[3] = new Dog("二汪",2,4.5,"哈巴");
        //public Bird(String name,int age,double weight,int flySpeed)
        ps[4] = new Bird("小叼",2,1.5,30);        
        ps[5] = new Bird("大叼",3,3.0,40);        
        //遍历输出数组
        for (Pet p : ps) {
            System.out.println(p);
        }
        System.out.println("-----------------------排序后------------------");
        //冒泡法按体重倒序重新排序
        for (int i = 0;i < ps.length - 1;i++) {
            for (int j = 0;j < ps.length - 1 - i;j++）{
                if (ps[j].getWeight() < ps[j + 1].getWeight()) {
                    Pet tmp = ps[j];
                    ps[j] = ps[j + 1];
                    ps[j + 1] = tmp;
                }
            }
        }
        //遍历输出数组
        for (Pet p : ps) {
            System.out.println(p);
            //p.speak();
            //p.eat();
        }
    }
}

public abstract class Frock {

    private int size;
    private String color;
    private double price;

    public Frock() {}

    public Frock(int size, String color, double price{
        this.size = size;
        this.color = color;
        this.price = price;
    }

    public void setSize(int size) {
        this.size = size;
    }

    public int getSize() {
        return size;
    }

    public void setColor(String color) {
        this.color = color;
    }

    public String getColor() {
        return color;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public double getPrice() {
        return price;
    }

    @Override
    public String toString() {
        return "尺寸:" + size + ",颜色:" + color + ",价格:" + price;
    }

    public abstract double calcArea();
}

class Shirt extends Frock {

    public Shirt() {}

    public Shirt(int size, String color, double price{
        super(size, color, price);
    }

    @Override
    public double calcArea() {
        return getSize() * 1.3;
    }
}

class FrockTest {

    public static void main(String[] args) {
        Frock f = new Shirt(180, "白色", 200);
        System.out.println(f);
        System.out.println(f.calcArea());
        Frock f2 = new Shirt();
        System.out.println(f2);
        System.out.println(f2.calcArea());
    }
}