Java深入探究关键字abstract的使用

public abstract void talk(); 

public class AbstractTest {
	public static void main(String[] args) {		
		//一旦Person类抽象了，就不可实例化
//		Person p1 = new Person();
//		p1.eat();		
	}
}
abstract class Creature{
	public abstract void breath();
}
abstract class Person extends Creature{
	String name;
	int age;	
	public Person(){		
	}
	public Person(String name,int age){
		this.name = name;
		this.age = age;
	}	
	//不是抽象方法：
//	public void eat(){
//		
//	}
	//抽象方法
	public abstract void eat();	
	public void walk(){
		System.out.println("人走路");
	}		
}
class Student extends Person{	
	public Student(String name,int age){
		super(name,age);
	}
	public Student(){
	}	
	public void eat(){
		System.out.println("学生多吃有营养的食物");
	}
	@Override
	public void breath() {
		System.out.println("学生应该呼吸新鲜的没有雾霾的空气");
	}
}

public class Test1 {
    public static void main(String args[]) {
        A a = new B();
        a.m1();//B类中定义的m1方法
        a.m2();//A类中定义的m2方法
    }
}
abstract class A {
    abstract void m1();
    public void m2() {
        System.out.println("A类中定义的m2方法");
    } 
}
class B extends A {
    void m1() {
        System.out.println("B类中定义的m1方法");
    } 
}

public class PersonTest {	
	public static void main(String[] args) {	
		//匿名对象		
		method(new Student());
		//非匿名的类非匿名的对象
		Worker worker = new Worker();
		method1(worker);
		//非匿名的类匿名的对象
		method1(new Worker());
		//创建了一匿名子类的对象：p
		Person p = new Person(){
			@Override
			public void eat() {
				System.out.println("吃东西");
			}
			@Override
			public void breath() {
				System.out.println("好好呼吸");
			}			
		};		
		method1(p);
		//创建匿名子类的匿名对象
		method1(new Person(){
			@Override
			public void eat() {
				System.out.println("吃好吃东西");
			}
			@Override
			public void breath() {
				System.out.println("好好呼吸新鲜空气");
			}
		});
	}		
	public static void method1(Person p){
		p.eat();
		p.breath();
	}	
	public static void method(Student s){		
	}
}
class Worker extends Person{
	@Override
	public void eat() {
	}
	@Override
	public void breath() {
	}	
}

abstract class Template {
   public final void getTime() {
      long start = System.currentTimeMillis();
      code();
      long end = System.currentTimeMillis();
      System.out.println("执行时间是：" + (end - start));
    }
      public abstract void code();
}
class SubTemplate extends Template {
      public void code() {
        for (int i = 0; i < 10000; i++) {
        System.out.println(i);
        } 
      } 
}