实验内容及要求：实现一个仿真农场，农场包括猫、狗、猪、马等动物。下面给出一个哺乳动物的 类，要求编写包括猫、狗、猪、马等动物的的类，并实现以下要求： 其中狗属哺乳动物，且它的属性有品种之分(在哺乳类基础上增加品种数属性)，叫声区别于其他动 物(输出“Woof!”)。令猫、马、猪也属于哺乳动物，其叫声分别为:“Meow!”，“Winnie!”，“Oink!”。编 程分别使各个动物表现为不一样的行为。 定义一个接口 Pet，猫和狗类需要实现 Pet 的所有方法。要求 Pet 包含如会摇尾巴(增加方法，输出 “Tail wagging…”)，乞讨食物(增加方法，输出“begging for food…”)等宠物行为。 哺乳动物类如下所示: public class Mammal{ protected int age = 2; protected int weight = 5; public Mammal(){ System.out.println(“Mammal constructor”); } int getAge(){ return age; } void setAge(int a){ age = a; } int getWeight(){ Acts(); class i class Nose(); extends i() 5 class Of76(); interface i(x) 7 class Clowns(); implements i[x] 7 public class Picasso(); Acts i.iMethod(x) public int iMethod(); Nose i(x).iMethod[] public int iMethod{} Of76 i[x].iMethod() public int iMethod(){ Clowns i[x].iMethod[] public int iMethod(){} Picasso Of76[] i = new Nose[3]; Of76[3] i; Nose[] i = new Nose(); Nose[] i = new Nose[3]; return weight; } void setWeight(int w){ weight = w; } void move(){ System.out.println(“Mammal move one step”); } void speak(){ System.out.println(“Mammal speak!”); } void sleep(){ System.out.println(“shhh, I’m sleeping.”); } }

下面是猫、狗、猪、马类的实现，以及Pet接口的定义和实现：

public interface Pet {
    void wagTail();
    void begFood();
}

public class Cat extends Mammal {
    public Cat() {
        System.out.println("Cat constructor");
    }
    void speak() {
        System.out.println("Meow!");
    }
    @Override
    public void move() {
        System.out.println("Cat move one step");
    }
    @Override
    public void sleep() {
        System.out.println("Purr, I'm sleeping.");
    }
    public void chaseMouse() {
        System.out.println("Cat is chasing the mouse.");
    }
    public void climb() {
        System.out.println("Cat is climbing the tree.");
    }
    public void wagTail() {
        System.out.println("Tail wagging...");
    }
    public void begFood() {
        System.out.println("Begging for food...");
    }
}

public class Dog extends Mammal implements Pet {
    private String breed;
    public Dog(String breed) {
        System.out.println("Dog constructor");
        this.breed = breed;
    }
    void speak() {
        System.out.println("Woof!");
    }
    @Override
    public void move() {
        System.out.println("Dog move one step");
    }
    @Override
    public void sleep() {
        System.out.println("Snore, I'm sleeping.");
    }
    public void fetch() {
        System.out.println("Dog is fetching the ball.");
    }
    public void sit() {
        System.out.println("Dog is sitting.");
    }
    public void wagTail() {
        System.out.println("Tail wagging...");
    }
    public void begFood() {
        System.out.println("Begging for food...");
    }
}

public class Pig extends Mammal {
    public Pig() {
        System.out.println("Pig constructor");
    }
    void speak() {
        System.out.println("Oink!");
    }
    @Override
    public void move() {
        System.out.println("Pig move one step");
    }
    @Override
    public void sleep() {
        System.out.println("Snort, I'm sleeping.");
    }
    public void rollInMud() {
        System.out.println("Pig is rolling in the mud.");
    }
    public void eat() {
        System.out.println("Pig is eating.");
    }
    public void wagTail() {
        System.out.println("Tail wagging...");
    }
    public void begFood() {
        System.out.println("Begging for food...");
    }
}

public class Horse extends Mammal {
    public Horse() {
        System.out.println("Horse constructor");
    }
    void speak() {
        System.out.println("Winnie!");
    }
    @Override
    public void move() {
        System.out.println("Horse move one step");
    }
    @Override
    public void sleep() {
        System.out.println("Neigh, I'm sleeping.");
    }
    public void gallop() {
        System.out.println("Horse is galloping.");
    }
    public void jump() {
        System.out.println("Horse is jumping.");
    }
    public void wagTail() {
        System.out.println("Tail wagging...");
    }
    public void begFood() {
        System.out.println("Begging for food...");
    }
}

其中，猫和狗类实现了Pet接口的所有方法，并且有各自独特的行为；猪和马类没有实现Pet接口，但仍然有各自独特的行为。