大话设计模式第八章之简单工厂模式

简单工厂模式

工厂方法模式

package com.dp.factory;

interface IFactory {
   Calculator CreateCalculator();
} 

class AddFactory implements IFactory
{

    @Override
    public Calculator CreateCalculator() {
      return new CalculatorAdd();
    }

}

class SubFactory implements IFactory
{

    @Override
    public Calculator CreateCalculator() {
         return new CalculatorMinus();
    }

}

class MulFactory implements IFactory
{

    @Override
    public Calculator CreateCalculator() {
        return new CalculatorMultiply();
    }

}

class DivFactory implements IFactory
{

    @Override
    public Calculator CreateCalculator() {
      return new CalculatorDivide();
    }

}

 abstract class  Calculator {
    protected double numberA=0;
    protected double numberB=0;
    public double getNumberA() {
        return numberA;
    }
    public void setNumberA(double numberA) {
        this.numberA = numberA;
    }
    public double getNumberB() {
        return numberB;
    }
    public void setNumberB(double numberB) {
        this.numberB = numberB;
    }    

    public abstract double getResult() throws Exception;
}

class CalculatorAdd extends Calculator
{
    @Override
    public double getResult() {
        double result=numberA+numberB;
       return result;
    }
}

class CalculatorMinus extends Calculator
{
    @Override
    public double getResult() {
        double result=numberA-numberB;
       return result;
    }
}

class CalculatorMultiply extends Calculator
{
    @Override
    public double getResult() {
        double result=numberA*numberB;
       return result;
    }
}

class CalculatorDivide extends Calculator
{
    @Override
    public double getResult() throws Exception {
        double result=numberA/numberB;
        if(numberB==0)
            throw new Exception("除数不能为0");
       return result;
    }
}

package com.dp.leifengFactory;

//简单工厂模式实现

public abstract class LeiFeng { public void sweep() { System.out.println("扫地"); } public void wash() { System.out.println("洗衣服"); } public void buyRice() { System.out.println("买米"); } } class Undergraduate extends LeiFeng { } class Volunteer extends LeiFeng { } class SimpleFactory { public static LeiFeng CreateLeiFeng(String type) { LeiFeng result=null; switch(type) { case "学雷锋的大学生": result=new Undergraduate(); break; case "志愿者": result=new Volunteer(); break; } return result; } }

package com.dp.leifengFactory;

public class Client {
   public static void main(String[] args) {
     LeiFeng StudentA=SimpleFactory.CreateLeiFeng("学雷锋的大学生");
     LeiFeng StudentB=SimpleFactory.CreateLeiFeng("学雷锋的大学生");
     LeiFeng StudentC=SimpleFactory.CreateLeiFeng("学雷锋的大学生");
}
}

使用工厂方法

package com.dp.leifengFactory;

public interface IFactory
{
  LeiFeng createLeifeng();
}

class UnderGraduateFactory implements IFactory
{

    @Override
    public LeiFeng createLeifeng() {
        // TODO Auto-generated method stub
        return new Undergraduate();
    }

}

class VolunteerFactory implements IFactory
{

    @Override
    public LeiFeng createLeifeng() {
        // TODO Auto-generated method stub
        return new Volunteer();
    }

}

abstract class LeiFeng
{
    public void sweep()
    {
        System.out.println("扫地");
    }

    public void wash()
    {
        System.out.println("洗衣服");
    }

    public void buyRice()
    {
        System.out.println("买米");
    }
}

class Undergraduate extends LeiFeng
{

}

class Volunteer extends LeiFeng
{

}

package com.dp.leifengFactory;

public class Client {
   public static void main(String[] args) {
   IFactory factory=new UnderGraduateFactory();
   LeiFeng lf=factory.createLeifeng();
   lf.buyRice();
}
}