class Student {
	public void study() {
		System.out.println("Good Good Study,Day Day Up");
	}
}

class StudentDemo {
	public void method(Student s) { 
		s.study();
	}
}

class StudentTest {
	public static void main(String[] args) {
		//需求1
		Student s = new Student();
		s.study();
		System.out.println("----------------");
		
		//需求2
		StudentDemo sd = new StudentDemo();
		Student ss = new Student();
		sd.method(ss);
		System.out.println("----------------");
		
		//匿名对象用法
		new StudentDemo().method(new Student());
	}
}

abstract class Person {
	public abstract void study();
}

class PersonDemo {
	public void method(Person p) {
		p.study();
	}
}

//定义一个具体的学生类
class Student extends Person {
	public void study() {
		System.out.println("Good Good Study,Day Day Up");
	}
}

class PersonTest {
	public static void main(String[] args) {
        // 直接使用是不行的，因为抽象类没有对应的具体类
        // 因此定于一个具体的类
		PersonDemo pd = new PersonDemo();	
        Person p = new Student();
        // 使用具体类调用method()
		pd.method(p);
	}
}

//定义一个爱好的接口
interface Love {
	public abstract void love();
}

class LoveDemo {
	public void method(Love l) { 
		l.love();
	}
}

//定义具体类实现接口
class Teacher implements Love {
	public void love() {
		System.out.println("极限挑战，这就是爱");
	}
}

class TeacherTest {
	public static void main(String[] args) {
		LoveDemo ld = new LoveDemo();
		Love l = new Teacher();
		ld.method(l);
	}
}

class Student {
	public void study() {
		System.out.println("Good Good Study,Day Day Up");
	}
}

class StudentDemo {
	public Student getStudent() {
		
	}
}

class StudentDemo {
	public Student getStudent() {
		return new Student();
	}
}

class StudentTest {
	public static void main(String[] args) {
		StudentDemo sd = new StudentDemo();
		Student s = sd.getStudent();
		s.study();
        // 链式编程
        sd.getStudent().study();
	}
}

abstract class Person {
	public abstract void study();
}

class PersonDemo {
	public Person getPerson() {
		
	}
}

class PersonDemo {
	public Person getPerson() {
        // Person p = new Student();  反抽象类的子类
		return new Student();
	}
}
// 创建一个具体类继承抽象类，重写study()方法
class Student extends Person {
	public void study() {
		System.out.println("Good Good Study,Day Day Up");
	}
}

class PersonTest {
	public static void main(String[] args) {
		PersonDemo pd = new PersonDemo();
		Person p = pd.getPerson(); 
		p.study();
	}
}

//定义一个爱好的接口
interface Love {
	public abstract void love();
}

class LoveDemo {
	public Love getLove() {
	}
}

class LoveDemo {
	public Love getLove() {
		//Love l = new Teacher();反回具体类对象
		return new Teacher();
	}
}

//定义具体类实现接口
class Teacher implements Love {
    // 重写Love()方法
	public void love() {
		System.out.println("极限挑战，这就是爱");
	}
}

class TeacherTest {
	public static void main(String[] args) {
		//测试
		LoveDemo ld = new LoveDemo();
		Love l = ld.getLove();
		l.love();
	}
}