设计模式——工厂模式

       工厂模式用来实例化对象并且实现实现与调用分离，用工厂模式来替代new。

      来看看这位老兄总结的吧，不想废话了。http://www.cnblogs.com/poissonnotes/archive/2010/12/01/1893871.html

        工厂模式有三种：

        1. 简单工厂模式
        2. 工厂方法模式
        3. 抽象工厂模式

      借用高淇老师的Demo

      简单工厂模式

      简单工厂模式也叫静态工厂模式，工厂类一般使用静态方法
      通过接收的参数不同来返回不同的对象实例
      但是对增加新产品无能为力，不增加代码无法扩展

     

public class CarFactory {
	public static Car creatCar(String name) {
		Car car = null;
		if(name.equals("benz")) {
			car = new Benz();
		}else if(name.equals("bmw")) {
			car = new BMW();
		}else if(name.equals("audi")) {
			car = new Audi();
		}
		return car;
 	}

}

public interface Car {
	void run();
}


public class BMW implements Car { 
	@Override
	public void run() {
		System.out.println("BMW running");
	}

}


public class Benz implements Car {
	@Override
	public void run() {
		System.out.println("Benz running");
	}

}

public class Audi implements Car {
	@Override
	public void run() {
		System.out.println("Audi running");
	}

}


public class Client {
	public static void main(String[] args) {
		//不用简单工厂模式的创建
		Car benz = new Benz();
		benz.run();
		Car bmw = new BMW();
		bmw.run();
		Car audi = new Audi();
		audi.run();
		System.out.println("+++++++++++++++++++++");
		
		//简单工厂
		Car benz2 = CarFactory.creatCar("benz");
		benz.run();
		Car bmw2 = CarFactory.creatCar("bmw");
		bmw.run();
		Car audi2 = CarFactory.creatCar("audi");
		audi.run();
		
	}
}

 

   工厂方法模式：

   工厂方法模式，避免了简单工厂的缺点，满足了OCP（开闭原则，对扩展开放，对修改关闭）原则。
   简单工厂只有一个工厂类，而工厂方法有一组实现了相同接口的工厂方法。
   工厂方法模式的缺点：结构和代码复杂度高，但是可扩展性好，客户端编程难度小。
   综合考虑，简单工厂模式，简单有一定的可扩展性。实际上简单工厂模式用的多。

  

public interface Car {
	void run();
}

public class Audi implements Car {
	@Override
	public void run() {
		System.out.println("Audi running");
	}

}

public class Benz implements Car {
	@Override
	public void run() {
		System.out.println("Benz running");
	}

}

public class BMW implements Car { 
	@Override
	public void run() {
		System.out.println("BMW running");
	}

}

public interface CarFactory {
	Car creatCar();
}


public class AudiFactory implements CarFactory {
	@Override
	public Car creatCar() {
		return new Audi();
	}

}

public class BenzFactory implements CarFactory {
	@Override
	public Car creatCar() {
		return new Benz();
	}
	

}

public class BMWFactory implements CarFactory { 
	@Override
	public Car creatCar() {
		return new BMW();
	}

}

public class Client {
	public static void main(String[] args) {
		//不用简单工厂模式的创建
		Car benz = new Benz();
		benz.run();
		Car bmw = new BMW();
		bmw.run();
		Car audi = new Audi();
		audi.run();
		System.out.println("+++++++++++++++++++++");
		
		//简单工厂
		Car benz2 = new BenzFactory().creatCar();
		benz.run();
		Car bmw2 = new BMWFactory().creatCar();
		bmw.run();
		Car audi2 = new AudiFactory().creatCar();
		audi.run();
		
	}
}

     抽象工厂模式：抽象工厂模式可以增加产品族，但是不可以增加新产品。纵向扩展。
    

public interface Seat {
	void massage();
}

class LuxurySeat implements Seat {

	@Override
	public void massage() {
		System.out.println("可以自动按摩！");
	}
	
}
class LowSeat implements Seat {

	@Override
	public void massage() {
		System.out.println("不可以自动按摩！");
	}
	
}

public interface Tyre {
	void revolve();
}

class LuxuryTyre implements Tyre {

	@Override
	public void revolve() {
		System.out.println("旋转不磨损！");
	}
	
}

class LowTyre implements Tyre {

	@Override
	public void revolve() {
		System.out.println("旋转磨损！");
	}
	
}

public interface Engine {
	void run();
	void start();
}


class LuxuryEngine implements Engine{

	@Override
	public void run() {
		System.out.println("转的快！");
	}

	@Override
	public void start() {
		System.out.println("启动快！");
	}
	
}

class LowEngine implements Engine{
	
	@Override
	public void run() {
		System.out.println("转的慢！");
	}
	
	@Override
	public void start() {
		System.out.println("启动慢");
	}
	
}


public interface CarFactory {
	Engine createEngine();
	Seat createSeat();
	Tyre createTyre();
}

public class LowCarFactory implements CarFactory {

	@Override
	public Engine createEngine() {
		return new LowEngine();
	}

	@Override
	public Seat createSeat() {
		return new LowSeat();
	}

	@Override
	public Tyre createTyre() {
		return new LowTyre();
	}


}

public class LuxuryCarFactory implements CarFactory {

	@Override
	public Engine createEngine() {
		return new LuxuryEngine();
	}

	@Override
	public Seat createSeat() {
		return new LuxurySeat();
	}

	@Override
	public Tyre createTyre() {
		return new LuxuryTyre();
	}


}

public class Client {

	public static void main(String[] args) {
		CarFactory  factory = new LuxuryCarFactory();
		Engine e = factory.createEngine();
		e.run();
		e.start();
		
		
	}
}