Java--设计模式之策略模式

策略模式，又叫算法簇模式，就是定义了不同的算法族，并且之间可以互相替换，此模式让算法的变化独立于使用算法的客户。简而言之就是用一个类来接收实例化对象，从而达到动态改变对象的行为。

通过商场促销来说明，例子如下：

1、基类收费

public interface CashSuper{
	public int acceptCash(int money);
}

2、实现基类--正常收费

public class CashNormal implements CashSuper{
	@Override
	public int acceptCash(int money) {
		return money;
	}
}

3、实现基类--打折收费

public class CashRebate implements CashSuper{
	private int moneyRebate;
	public CashRebate(int moneyRebate) {
		super();
		this.moneyRebate = moneyRebate;
	}
	@Override
	public int acceptCash(int money) {
		return money*moneyRebate;
	}
	public int getMoneyRebate() {
		return moneyRebate;
	}
	public void setMoneyRebate(int moneyRebate) {
		this.moneyRebate = moneyRebate;
	}
}

4、实现基类--返利收费

public class CashReturn implements CashSuper{
	private int moneyCondition;
	private int moneyReturn;
	public CashReturn(int moneyCondition, int moneyReturn) {
		super();
		this.moneyCondition = moneyCondition;
		this.moneyReturn = moneyReturn;
	}
	@Override
	public int acceptCash(int money) {
		int result = money;
		if(money>moneyCondition){
			result = money - money/moneyCondition *moneyReturn;
		}
		return result;
	}
	public int getMoneyCondition() {
		return moneyCondition;
	}
	public void setMoneyCondition(int moneyCondition) {
		this.moneyCondition = moneyCondition;
	}
	public int getMoneyReturn() {
		return moneyReturn;
	}
	public void setMoneyReturn(int moneyReturn) {
		this.moneyReturn = moneyReturn;
	}
}

5、策略实现类

public class CashContext {
	private CashSuper cashSuper;
	public CashContext(CashSuper cashSuper){
		this.cashSuper = cashSuper;
	}
	public int getResult(int money){
		return cashSuper.acceptCash(money);
	}
}