练习1：使用重写优化电子宠物系统
需求说明 使用方法重写优化电子宠物系统，实现如下效果
package com.hz.ch02;
/**
* 猫类
* @author 26255
*
*/
public class Cat extends Father {
private String sex;
public Cat(String name, int health, int love, String sex) {
super(name, health, love);
this.sex = sex;
}
public void print() {
super.print();
System.out.println(",品种"+this.getSex());
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
}
package com.hz.ch02;
/**
* 狗类
* @author 26255
*
*/
public class Dog extends Father{
private String type;
public Dog(String name, int health, int love, String type) {
super(name, health, love);
this.type = type;
}
public void print() {
super.print();
System.out.println(",品种"+this.getType());
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
}
package com.hz.ch02;
/**
* 父类
* @author 26255
*
*/
public class Father {
private String name;
private int health;
private int love;
public Father(String name, int health, int love) {
super();
this.name = name;
this.health = health;
this.love = love;
}
public void print() {
System.out.println("我的名字是"+this.getName()+"，健康值"+this.getHealth()+"，亲密度"+this.getLove());
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getHealth() {
return health;
}
public void setHealth(int health) {
this.health = health;
}
public int getLove() {
return love;
}
public void setLove(int love) {
this.love = love;
}
}
package com.hz.ch02;
public class Lianx {
public static void main(String[] args) {
// TODO Auto-generated method stub
Dog d = new Dog("白菜",100,100,"哈士奇");
d.print();
Cat s = new Cat("为2",60,70,"雌性");
s.print();
}
}
运行：
我的名字是白菜，健康值100，亲密度100
,品种哈士奇
我的名字是为2，健康值60，亲密度70
,品种雌性
练习2：重写equals()
需求说明 重写比较规则，判断两名学员（Student）是否为同一对象 Student相关属性 Id（学号）、name（姓名）、age（年龄） 如果两名学员的学号以及姓名相同，则为同一对象
instanceof用于判断一个引用类型所引用的对象是否是一个类的实例
package com.hz.ch01;
/**
* 学生类
*/
public class Father {
private String name;
private String id;
private int age;
public boolean equals(Object obj) {
if(obj instanceof Father) {
Father m1 = (Father) obj;
return this.name==m1.name&&this.id==m1.id;
}
return false;
}
public Father(String name, String id, int age) {
this.name = name;
this.id = id;
this.age = age;
}
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 getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
package com.hz.ch01;
public class Lianx1 {
public static void main(String[] args) {
// TODO Auto-generated method stub
Father m = new Father("张三","qq",25);
Father m1 = new Father("张三","qq",20);
System.out.println(m.equals(m1));
}
}
运行：
true练习3：使用多态实现为宠物喂食
需求说明 宠物饿了，主人需要为宠物喂食，使用多态实现该过程 不同宠物吃的东西不一样 不同宠物吃完东西后恢复健康值不一样 健康值达到100时，不需要继续喂食
package com.hz.ch03;
/**
* 父类
* @author 26255
*
*/
public class Pet {
private int health;
public Pet(int health) {
this.health = health;
}
public int getHealth() {
return health;
}
//判断健康值
public void setHealth(int health) {
this.health = health;
if(this.health>100) {
this.health=100;
System.out.println("健康值已到100，不需要继续喂食");
}
}
public void eat(String un) {
}
}
package com.hz.ch03;
/**
* 狗狗类
* @author 26255
*
*/
public class Dog extends Pet{
public Dog(int health) {
super(health);
}
public void eat(String un) {
System.out.println("狗狗的初始健康值"+getHealth()+"，狗狗想吃"+un+"狗狗吃到了"+un+",健康值加三3");
setHealth(getHealth()+3);
}
}
package com.hz.ch03;
/**
* 企鹅类
* @author 26255
*
*/
public class Penuin extends Pet{
public Penuin(int health) {
super(health);
}
public void eat(String un) {
System.out.println("企鹅的初始健康值"+getHealth()+"，企鹅想吃"+un+"企鹅吃到了"+un+",健康值加三5");
setHealth(getHealth()+5);
}
}
package com.hz.ch03;
/**
* 主人类
* @author 26255
*
*/
public class Person {
public void un(Pet pet,String un) {
pet.eat(un);
String s = un;
}
}
package com.hz.ch03;
public class Lianx {
public static void main(String[] args) {
// TODO Auto-generated method stub
Person person = new Person();
Pet dog = new Dog(70);
person.un(dog,"骨头");
System.out.println("狗狗吃完后的健康值是："+dog.getHealth());
Pet penuin = new Penuin(80);
person.un(penuin, "鱼");
System.out.println("企鹅吃完后的健康值是:"+penuin.getHealth());
}
}
运行：
狗狗的初始健康值70，狗狗想吃骨头狗狗吃到了骨头,健康值加三3
狗狗吃完后的健康值是：73
企鹅的初始健康值80，企鹅想吃鱼企鹅吃到了鱼,健康值加三5
企鹅吃完后的健康值是:85练习4：使用多态实现主人领养宠物并与宠物玩耍功能
需求说明 狗具有特有的接飞盘方法，企鹅具有特有的南极游泳方法。请编写测试类分别调用各种具体宠物的特有方法 使用向下转型 使用instanceof判断宠物类型
package com.hz.ch04;
/**
* 父类
* @author 26255
*
*/
public class Pet {
private String name;
private int health=80;//健康值
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getLove() {
return love;
}
public void setLove(int love) {
this.love = love;
}
public void setHealth(int health) {
this.health = health;
}
private int love=50;//亲密度
public Pet(String name, int health, int love) {
super();
this.name = name;
this.health = health;
this.love = love;
}
public int getHealth() {
return health;
}
}
package com.hz.ch04;
/**
* 主人类
* @author 26255
*
*/
public class Person {
private String name;
private int age;
public Person(String name, int age) {
super();
this.name = name;
this.age = age;
}
public void play(Pet pet) {
if(pet instanceof Dog) {
Dog dog = (Dog)pet;
dog.fly();
}else if(pet instanceof Penuin) {
Penuin p = (Penuin)pet;
p.sw();
}
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
package com.hz.ch04;
/**
* 狗狗类
* @author 26255
*
*/
public class Dog extends Pet{
private String strain;//品种
public Dog(String name, int health, int love, String strain) {
super(name, health, love);
this.strain = strain;
}
public void fly() {
System.out.println("小狗正在接飞盘！");
System.out.println("健康值:"+super.getHealth()+10);
System.out.println("亲密度:"+super.getLove()+5);
}
public String getStrain() {
return strain;
}
public void setStrain(String strain) {
this.strain = strain;
}
}
package com.hz.ch04;
/**
* 企鹅类
* @author 26255
*
*/
public class Penuin extends Pet{
private String sex;
public Penuin(String name, int health, int love, String sex) {
super(name, health, love);
this.sex = sex;
}
public void sw() {
System.out.println("企鹅正在滑冰！");
System.out.println("健康值:"+super.getHealth()+10);
System.out.println("亲密度:"+super.getLove()+5);
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
}
package com.hz.ch04;
public class Lianx {
public static void main(String[] args) {
Person m = new Person(null, 0);
m.play(new Dog("zhang ", 0, 0, "hiw"));
m.play(new Penuin("hduh ", 0, 0, "fwh"));
}
}
运行:
小狗正在接飞盘！
健康值:010
亲密度:05
企鹅正在滑冰！
健康值:010
亲密度:05
练习5：打印商品价格
需求说明 自定义类和方法，使用父类作为返回值实现打印不同类型商品价格功能 父类：Goods（商品类） 子类：TVs（电视类）、Foods（食品类）
package com.hz.ch05;
/**
* 厂家
* @author 26255
*
*/
public class Plant {
public Goods Goods(String type) {
Goods goods = null;
if(type.equals("tv")) {
goods = new TVs();
}else if(type.equals("食品")) {
goods = new Foods();
}
return goods;
}
}
package com.hz.ch05;
/**
* 食品类
* @author 26255
*
*/
public class Foods extends Goods{
public void print() {
System.out.println("食品价格：100");
}
}
package com.hz.ch05;
/**
* 父类
* @author 26255
*
*/
public abstract class Goods {
private int price;//价格
public int getPrice() {
return price;
}
public void setPrice(int price) {
this.price = price;
}
public abstract void print();
}
package com.hz.ch05;
/**
* 电视类
* @author 26255
*
*/
public class TVs extends Goods{
public void print() {
System.out.println("电视价格：4999");
}
}
package com.hz.ch05;
public class Lianxi {
public static void main(String[] args) {
Plant p1 = new Plant();
Goods goods = p1.Goods("tv");
goods.print();
goods = p1.Goods("食品");
goods.print();
}
}
运行:
电视价格：4999
食品价格：100