Java版大话设计模式（二）---计算器商场促销---策略模式

package dataStruct;


abstract class CashSuper {

public abstract double acceptCash(double money);

}
//正常收费子类
class CashNormal extends CashSuper {

@Override
public double acceptCash(double money) {

return money;

}

}
//打折收费子类
class CashRebate extends CashSuper {

private double moneyRebate = 1.0;
public CashRebate(double moneyRebate) {

super();

this.moneyRebate = moneyRebate;

}
@Override
public double acceptCash(double money) {

return money*moneyRebate;

}

}
//返利收费子类
class CashReturn extends CashSuper {

private double moneyCondition = 0.0;
private double moneyReturn = 0.0;
public CashReturn(double moneyCondition, double moneyReturn) {

super();

this.moneyCondition = moneyCondition;

this.moneyReturn = moneyReturn;

}

@Override
public double acceptCash(double money) {

double result = money;

if(money >= moneyCondition) {

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

}

return result;

}

}




//策略模式类（结合工厂模式）
class CashContext {

CashSuper cs = null;
public CashContext(String type) {
switch(type) {

case "正常收费":

cs = new CashNormal();

break;

case "满300反100":

cs = new CashReturn(300,100);

break;

case "打8折":

cs = new CashRebate(0.8);

break;

}

}

public double getResult(double money) {

return cs.acceptCash(money);

}

}


//客户端代码
public class Main  
{   
   public static void main(String[] args) throws Exception  {

   CashContext cc1 = new CashContext("满300反100");
   System.out.println(cc1.getResult(1000));
   CashContext cc2 = new CashContext("打8折");
   System.out.println(cc2.getResult(1000));

   }
}