大话设计模式_策略模式

本文以 商场促销 为例子来实现这种模式。

商场三种活动：

1.按照原来价格收费

2.八折收费

3.满300反100

一：工厂模式实现

二：策略模式实现

三：工厂+策略模式实现

package com.wzs.design;

/**
 * 工厂模式的实现
 * 
 * @author Administrator
 * 
 */
public class SimpleFactory_1 {
	public static void main(String[] args) {
		CashFactory cashFactory = new CashFactory();
		System.out.println(cashFactory.createCashAccept(1).acceptCash(500));
		System.out.println(cashFactory.createCashAccept(2).acceptCash(500));
		System.out.println(cashFactory.createCashAccept(3).acceptCash(500));
		System.out.println(cashFactory.createCashAccept(4).acceptCash(500));
	}
}

/*
 * 现金收费工厂
 */
class CashFactory {
	public CashSuper createCashAccept(int type) {
		CashSuper cashSuper = null;
		switch (type) {
		case 1:
			System.out.println("正常收费.");
			cashSuper = new CashNormal();
			break;
		case 2:
			System.out.println("八折收费.");
			cashSuper = new CashRebate(0.8);
			break;
		case 3:
			System.out.println("满300反100.");
			cashSuper = new CashReturn(300, 100);
			break;
		default:
			System.out.println("默认正常收费.");
			cashSuper = new CashNormal();
			break;
		}
		return cashSuper;
	}
}

/*
 * 现金收取抽象类
 */
abstract class CashSuper {
	public abstract double acceptCash(double money);
}

/*
 * 正常收费
 */
class CashNormal extends CashSuper {
	@Override
	public double acceptCash(double money) {
		return money;
	}
}

/*
 * 打折收费
 */
class CashRebate extends CashSuper {
	private double moneyRebate = 1d;// 打折率

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

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

/*
 * 返利
 */
class CashReturn extends CashSuper {
	private double moneyCondition = 0d;// 返利条件
	private double moneyReturn = 0d;// 返利值

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

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

}

---------------------------------------------------

package com.wzs.two;

import java.util.Scanner;

/**
 * 策略模式
 * 
 * @author Administrator
 * 
 */
public class StrategyPattern {
	public static void main(String[] args) {
		System.out.println("请输入收费模式:(1.正常收费 2.八折收费 3.满300反100)");
		Scanner input = new Scanner(System.in);
		int type = input.nextInt();

		CashContext cashContext;
		switch (type) {
		case 1:
			System.out.println("正常收费.");
			cashContext = new CashContext(new CashNormal());
			break;
		case 2:
			System.out.println("八折收费.");
			cashContext = new CashContext(new CashRebate(0.8));
			break;
		case 3:
			System.out.println("满300反100.");
			cashContext = new CashContext(new CashReturn(300, 100));
			break;
		default:
			System.out.println("默认正常收费.");
			cashContext = new CashContext(new CashNormal());
			break;
		}
		System.out.println(cashContext.getResult(500));
	}
}

/*
 * 收费策略
 */
class CashContext {
	private CashSuper cashSuper;

	public CashContext(CashSuper cashSuper) {
		this.cashSuper = cashSuper;
	}

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

}

/*
 * 现金收取抽象类
 */
abstract class CashSuper {
	public abstract double acceptCash(double money);
}

/*
 * 正常收费
 */
class CashNormal extends CashSuper {
	@Override
	public double acceptCash(double money) {
		return money;
	}
}

/*
 * 打折收费
 */
class CashRebate extends CashSuper {
	private double moneyRebate = 1d;// 打折率

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

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

/*
 * 返利
 */
class CashReturn extends CashSuper {
	private double moneyCondition = 0d;// 返利条件
	private double moneyReturn = 0d;// 返利值

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

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

}

---------------------------------------------------

package com.wzs.three;

/**
 * 策略模式和工厂模式结合
 * 
 * @author Administrator
 * 
 */
public class StrategyAndFactory {
	public static void main(String[] args) {
		System.out.println(new CashContext(1).getResult(500));
		System.out.println(new CashContext(2).getResult(500));
		System.out.println(new CashContext(3).getResult(500));
		System.out.println(new CashContext(4).getResult(500));
	}
}

/*
 * 收费策略
 */
class CashContext {
	private CashSuper cashSuper;

	public CashContext(int type) {
		switch (type) {
		case 1:
			System.out.println("正常收费.");
			cashSuper = new CashNormal();
			break;
		case 2:
			System.out.println("八折收费.");
			cashSuper = new CashRebate(0.8);
			break;
		case 3:
			System.out.println("满300反100.");
			cashSuper = new CashReturn(300, 100);
			break;
		default:
			System.out.println("默认正常收费.");
			cashSuper = new CashNormal();
			break;
		}
	}

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

}

/*
 * 现金收取抽象类
 */
abstract class CashSuper {
	public abstract double acceptCash(double money);
}

/*
 * 正常收费
 */
class CashNormal extends CashSuper {
	@Override
	public double acceptCash(double money) {
		return money;
	}
}

/*
 * 打折收费
 */
class CashRebate extends CashSuper {
	private double moneyRebate = 1d;// 打折率

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

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

/*
 * 返利
 */
class CashReturn extends CashSuper {
	private double moneyCondition = 0d;// 返利条件
	private double moneyReturn = 0d;// 返利值

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

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

}