设计模式2---工厂模式

为了解决简单工厂模式的缺点，我们通过接口IFactory抽象出工厂类，然后每次增加一个操作类，我就增加工厂类，

从而达到：对扩展开放，对修改关闭。

还是计算器的问题：

UML如下：

 

factory 基类：

public interface IOperatorFactory {

    AbstractOperator CreateOperation();

}

工厂类：

package com.jayfulmath.designpattern.factory;



import com.jayfulmath.designpattern.samplefactory.operator.AbstractOperator;

import com.jayfulmath.designpattern.samplefactory.operator.OperatorAdd;



public class AddFactory implements IOperatorFactory {



    @Override

    public AbstractOperator CreateOperation() {

        // TODO Auto-generated method stub

        return new OperatorAdd();

    }



}

package com.jayfulmath.designpattern.factory;



import com.jayfulmath.designpattern.samplefactory.operator.AbstractOperator;

import com.jayfulmath.designpattern.samplefactory.operator.OperatorPlus;



public class PlusFactory implements IOperatorFactory {



    @Override

    public AbstractOperator CreateOperation() {

        // TODO Auto-generated method stub

        return new OperatorPlus();

    }



}

main：

package com.jayfulmath.designpattern.factory;



import com.jayfulmath.designpattern.main.BasicExample;

import com.jayfulmath.designpattern.samplefactory.operator.AbstractOperator;



public class FactoryMain extends BasicExample {



    @Override

    public void startDemo() {

        // TODO Auto-generated method stub

        IOperatorFactory addFactory = new AddFactory();

        AbstractOperator addOperation = addFactory.CreateOperation();

        addOperation.NumberA = 1;

        addOperation.NumberB = 2;

        System.out.println("[FactoryMain]"+addOperation.NumberA+" add "+addOperation.NumberB+" = "+addOperation.GetResult());    

    }



}

工厂接口生成操作基类。