继承
package girlfriend;
/*final*/ class Creature { //定义生物类
//final 关键字声明类可以把类定义为不能继承的，即最终类；
//或者用于修饰方法，该方法不能被子类重写：
//定义属性
int biological_energy;
String shape;
//定义构造器
public Creature(int biological_energy,String shape){
this.biological_energy = biological_energy;
this.shape = shape; //this关键字区别成员变量和形参
}
//定义方法
public /*final*/ void getpower(){
System.out.println("Creature get power from solar power");
}
}
class Rose extends Creature{ //定义玫瑰类
//扩展属性
String smell;
String color;
//定义构造器
public Rose(int biological_energy,String shape,String smell,String color){
super(85,"complicated");
//显式地通过super关键字调用父类的构造器并配以适当的参数列表,默认调用super（）；
this.biological_energy = biological_energy;
this.shape = shape;
this.smell = smell;
this.color = color;
}
//定义方法(重写方法)
public void getpower(){
System.out.println("Rose get power from water,sunshine,soil...");
}
public void getTest(){
//this'调用自己的方法
this.getpower();
//super调用父类的方法
super.getpower();
}
}
public class grilfriend
{
public static void main(String[] args)
{
Creature creature = new Creature(85,"complicated");
creature.getpower();
Rose rose = new Rose(56,"magnificant","Fangrance","red and white");
rose.getTest();
}
}
抽象
abstract class Person
{
//定义属性
public String name;
public int age;
public char gender;
//定义方法（只允许声明，不允许实现）
public abstract void setname(String name);
public abstract void setage(int age);
public abstract void showinfo();
}
public class Abstract extends Person
{
//重写方法
public void setname(String name)
{
this.name=name;
}
public void setage(int age)
{
this.age=age;
}
public void showinfo()
{
System.out.println(name);
System.out.println(age);
}
public static void main(String []args)
{
Abstract s = new Abstract();
s.setname("lili");
s.setage(12);
s.showinfo();
}
}
接口
interface Animal
{
//接口没有构造方法
void eat();
void sleep();
}
interface Creature
{
void getpower();
void outpower();
}
interface Cat extends Animal,Creature
{
void run();
void voice();
}
public class Interface implements Cat
//一个类可以继承多个接口，但接口的每个方法都得实现，除非是抽象类
{
public void eat(){
System.out.println("Animal need to eat");
}
public void sleep(){
System.out.println("Animal need to sleep");
}
public void getpower(){
System.out.println("Crature need to getpower");
}
public void outpower(){
System.out.println("Crature need to outpower");
}
public void run(){
System.out.println("Cat can run");
}
public void voice(){
System.out.println("Cat can voice");
}
public static void main(String []args){
Interface bofi = new Interface();
bofi.eat();
bofi.sleep();
bofi.getpower();
bofi.outpower();
bofi.run();
bofi.voice();
}
}