實驗一：

實驗目的：

掌握怎麼實現藉口

interface ComputerAverage{
	public double average(double x[]);
}

class Gymnastics implements ComputerAverage{
	public double average(double x[]){
		int count=x.length;
		double aver=0,temp=0;
		for(int i=0;i<count;i++){
			for(int j=i+1;j<count;j++){
				if(x[j]<x[i]){
					temp=x[j];
					x[j]=x[i];
					x[i]=temp;
				}
			}
		}
		
		for(int i=1;i<count-1;i++)
			aver+=x[i];
		if(aver>2)
			aver/=(count-2);
		else
			aver=0;
		
		return aver;
	}
}

class School implements ComputerAverage{
	double aver=0;
	public double average(double x[]){
		for(int i=0;i<x.length;i++)
			aver+=x[i];
		return aver/x.length;
	}
}

public class Main{
	public static void main(String args[]){
		double a[]={1,2,3,4,5,6,3,10,22,5,6};
		double b[]={12,35,215,454,236,4546,121};
		
		ComputerAverage computer=new Gymnastics();
		double result=computer.average(a);
		System.out.println(result);
		
		computer=new School();
		result=computer.average(b);
		System.out.println(result);
	}
}

 

實驗二：

實驗目的

掌握介面回撥技術

interface ComputerWeight{
	public double computerWeight();
}

class Television implements ComputerWeight{
	public double computerWeight(){
		return 3.5;
	}
}

class Computer implements ComputerWeight{
	public double computerWeight(){
		return 2.67;
	}
}

class WashMachine implements ComputerWeight{
	public double computerWeight(){
		return 13.8;
	}
}

class Truck{
	ComputerWeight[] goods;
	double totalWeights=0;
	Truck(ComputerWeight[] goods){
		this.goods =goods;
	}
	
	public void setGoods(ComputerWeight[] goods){
		this.goods =goods;
	}
	
	public double getTotalWeights(){
		for(int i=0;i<goods.length;i++)
			totalWeights+=goods[i].computerWeight();
		return totalWeights;
	}
}

public class Main{
	public static void main(String args[]){
		ComputerWeight[] goods=new ComputerWeight[650];
		for(int i=0;i<goods.length;i++){
			if(i%3==0)
				goods[i]=new Television();
			else if(i%3==2)
				goods[i]=new Computer();
			else
				goods[i]=new WashMachine();
		}
		
		
		Truck truck=new Truck(goods);
		System.out.println(truck.getTotalWeights());
		
		
		goods=new ComputerWeight[68];
		for(int i=0;i<goods.length;i++){
			if(i%2==0)
				goods[i]=new Television();
			else
				goods[i]=new WashMachine();
		}
		truck.setGoods(goods);
		System.out.println(truck.getTotalWeights());
	}
}
 

實驗三：

實驗目的：

掌握介面技術以及思想

interface dog{
	public void showState();
}

class SoftlyState implements dog{
	public void showState(){
		System.out.println("聽主人的命令");
	}
}
class MeetEnemyState implements dog{
	public void showState(){
		System.out.println("狂叫");
	}
}
class MeetFrientsState implements dog{
	public void showState(){
		System.out.println("搖尾巴");
	}
}
class MeetAnotherState implements dog{
	public void showState(){
		System.out.println("玩耍");
	}
}


class dogShow{
	dog state;
	public void show(){
		state.showState();
	}
	public void setState(dog a){
		state=a;
	}
}


public class Main{
	public static void main(String args[]){
		dogShow yellowDog=new dogShow();
		
		System.out.println("狗在主人前面");
		yellowDog.setState(new SoftlyState());
		yellowDog.show();
		
		System.out.println("狗在敵人前面");
		yellowDog.setState(new MeetEnemyState());
		yellowDog.show();
		
		System.out.println("狗在朋友前面");
		yellowDog.setState(new MeetFrientsState());
		yellowDog.show();
		
		System.out.println("狗在同伴前面");
		yellowDog.setState(new MeetAnotherState());
		yellowDog.show();
	}
}