策略模式的基本运用

/**
* 现金收费抽象类
*/
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=1d;

public CashRebate(double moneyRebate){
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=0.0d;//返利条件
private double moneyReturn=0.0d;

public CashReturn(double moneyCondition,double moneyReturn){
this.moneyCondition=moneyCondition;
this.moneyReturn=moneyReturn;
}

@Override
public double acceptCash(double money) {
double result=money;
//当前费用大于返利条件
if(money>=moneyCondition){
result=money-Math.floor(money/moneyCondition)*moneyReturn;
}
return result;
}
}

/**
* 上下文
*/
class CashContext{
CashSuper cs=null;

public CashContext(String type){
switch (type){
case "正常收费":
CashNormal cs0=new CashNormal();
cs=cs0;
break;
case "满300返100":
CashReturn cr1=new CashReturn(300,100);
cs=cr1;
break;
case "打八折":
CashRebate cr2=new CashRebate(0.8);
cs=cr2;
break;
}
}

public double GetResult(double money){
return cs.acceptCash(money);
}
}

/**
* 客户端调用
*/
public class Strategy {
public static void main(String[] args){
CashContext csuper=new CashContext("正常收费");
double prices=csuper.GetResult(1000);
CashContext csuper2=new CashContext("满减");
double prices2=csuper2.GetResult(1000);
}

}