策略模式解析

import java.util.*;

enum TYPE { NORMAL,CASH_DISCOUNT,CASH_RETURN};

interface Cashsuper {

public double acceptCash(double money);

}

class CashNormal implements CashSuper{// 正常收费子类

public double accptCash(double money){

return money;

}

}

class CashDiscount implements Cashsuper {

private double moneyDiscount; //折扣率

public CashDiscount(double moneyDiscount){

this moneyDiscount = moneyDiscount;

}

public double acceptCash(double money){

return money* moneyDiscount;

}

}

class CashReturn implements Cashsuper { //满额返利

private double moneyCondition;

private double moneyReturn;

public CashReturn(double moneyCondition, double moneyReturn){

this.moneycondition =moneyCondition;//满额数额

this.moneyReturn =moneyReturn;//返利数额

}

public double acceptCash(double money){

double result = money;

if (money >= moneyCondition )

result=money-Math.floor(money/moneyCondition )* moneyReturn;

return result;

}

}

class CashContext{

private Cashsuper cs;

private TYPE t;

public CashContext(TYPE t){

switch(t){

case NORMAL;// 正常收费

cs= new CashNormal();

break;

case CASH_RETURN;//满300返100

cs = new CashReturn(300,100);

break;

case CASH_DISCOUNT;//打8折

cs =new CashDiscount(0.8);

break;

}

}

public double GetResult(double money){

return cs.acceptCash(money);

}

//此处略去main()函数：选择哪一种策略,输入金额

}