一、简单工厂模式

简单工厂模式：只是用来解决创建对象的问题；每个对象都有共同的行为（方法），但是具体的实现不同；

需求如下：给一商场做一个结算软件，这个结算总共包括“正常收费”，“满300减100”，“打八折”几项；这个例子就能使用简单工厂模式；

1.首先将共同的行为抽象出来：接收一个没有活动的支付额，返回一个参与活动后的支付额

package com.zcbl.client.zcblsdk.factorymodel;

/**
 * Created by serenitynanian on 2018/2/2.
 */

public abstract class CashSuper {

    public abstract double acceptCash(double money);
}

2.分别创建“正常收费”，“满300减100”，“打八折”这三个活动的类；

package com.zcbl.client.zcblsdk.factorymodel.impl;

import com.zcbl.client.zcblsdk.factorymodel.CashSuper;

/**
 * Created by serenitynanian on 2018/2/2.
 * 正常收费
 */

public class CashNormal extends CashSuper {
    @Override
    public double acceptCash(double money) {
        return money;
    }
}

package com.zcbl.client.zcblsdk.factorymodel.impl;

import com.zcbl.client.zcblsdk.factorymodel.CashSuper;

/**
 * Created by serenitynanian on 2018/2/2.
 * 现金折扣
 */

public class CashRebate extends CashSuper {
    private double moneyRebate ;

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

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

package com.zcbl.client.zcblsdk.factorymodel.impl;

import com.zcbl.client.zcblsdk.factorymodel.CashSuper;

/**
 * Created by serenitynanian on 2018/2/2.
 * 返利收费子类
 */

public class CashReturn extends CashSuper {
    private double moneyCondition ;
    private double moneyReturn ;

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

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

3.创建现金收费工厂类，来根据传入的活动类型来创建相应的实例；

package com.zcbl.client.zcblsdk.factorymodel;

import com.zcbl.client.zcblsdk.factorymodel.impl.CashNormal;
import com.zcbl.client.zcblsdk.factorymodel.impl.CashRebate;
import com.zcbl.client.zcblsdk.factorymodel.impl.CashReturn;

/**
 * Created by serenitynanian on 2018/2/2.
 * 简单工厂模式：这个模式只是用来解决创建对象的问题；
 * 现金收费工厂类
 */
public class CashFactory {

    public static CashSuper createCashAccept(String type){
        CashSuper cs = null ;
        switch (type) {
            case "正常收费":
                cs = new CashNormal();
                break ;
            case "满300减100":
                cs = new CashReturn(300, 100);
                break ;
            case "打八折":
                cs = new CashRebate(0.8);
                break ;

        }
        return cs ;
    }

    public static void main(String[] args) {
        CashSuper cs = CashFactory.createCashAccept("打八折");
        double result = cs.acceptCash(100);
        System.out.println("----result----->"+result);
    }
}