大话设计模式java版本 第二章 策略模式

package strategy;

//嵌入策略
public class CashContext {
    private Cash cs;

    public CashContext(Cash cs) {
        super();
        this.cs = cs;
    }

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

}

package strategy;

public interface Cash {
    public abstract double acceptCash(double money);
}

package strategy;
/*
 * 正常收费
 */
public class CashNormal implements Cash{

    @Override
    public double acceptCash(double money) {

        return money;
    }

}

package strategy;
/*
 * 打折策略
 */
public class CashRebate implements Cash{
    private double moneyRebate;

    public CashRebate() {
        super();
    }

    public CashRebate(double moneyRebate) {
        super();
        this.moneyRebate = moneyRebate;
    }

    public double getMoneyRebate() {
        return moneyRebate;
    }

    public void setMoneyRebate(double moneyRebate) {
        this.moneyRebate = moneyRebate;
    }

    @Override
    public double acceptCash(double money) {
            return money*moneyRebate;
    }

}

package strategy;
/*
 * 返利收费策略
 */

public class CashReturn implements Cash {
    private double moneyCondition;
    private double moneyReturn;

    public CashReturn() {
        super();
    }

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

    public double getMoneyCondition() {
        return moneyCondition;
    }

    public void setMoneyCondition(double moneyCondition) {
        this.moneyCondition = moneyCondition;
    }

    public double getMoneyReturn() {
        return moneyReturn;
    }

    public void setMoneyReturn(double moneyReturn) {
        this.moneyReturn = moneyReturn;
    }

    @Override
    public double acceptCash(double money) {
        if(money>=moneyCondition){
            return money-(int)(money/moneyCondition)*moneyReturn;
        }
        return money;
    }

}

测试类：

package strategy;

import java.util.Scanner;

/*
 * 测试代码
 */
public class test {
    public static void main(String[] args) {
        CashContext cc=null;
        double moneyRebate=0;
        double money=0;
        Scanner sc= new Scanner(System.in);
        System.out.println("请输入折扣类型");
        String type = sc.next();
        switch (type) {
        case "正常收费":
            cc=new CashContext(new CashNormal());
            break;

        case "打折":
            System.out.println("请输入打折比例");
            moneyRebate=sc.nextDouble();
            cc=new CashContext(new CashRebate(moneyRebate));
            break;

        case "返利":
            cc=new CashContext(new CashReturn(500, 50));
            break;
        }
        System.out.println("请输入金额");
        money = sc.nextDouble();
        System.out.println(cc.getResult(money));
    }
}