设计模式备忘之简单工厂

package org.wikimore.simplefactory;

import javax.naming.NameNotFoundException;

//汽车工厂类，可生产已定义的种类的汽车，否则报异常
public class CarFactory {
	public Car buildcar(String brand) throws Exception {
		if ("BMW".equalsIgnoreCase(brand)){
			return new BMW();
		}else if("Benz".equalsIgnoreCase(brand)){
			return new Benz();
		}else if("volvo".equalsIgnoreCase(brand)){
			return new Volvo();
		}else
			throw new NameNotFoundException("工厂不能生产这个牌子的汽车");
	}
}

 

package org.wikimore.simplefactory;

//汽车父类
public class Car {
	
}

 

 下面是汽车子类

 

package org.wikimore.simplefactory;

public class Benz extends Car {
	public Benz() {
		System.out.println("A Benz was build!");
	}
}

package org.wikimore.simplefactory;

public class BMW extends Car {
	public BMW() {
		System.out.println("A BMW was build!");
	}
}


package org.wikimore.simplefactory;

public class Volvo extends Car{
	public Volvo() {
		System.out.println("A volvo was build!");
	}
}

 

 测试类

 

package org.wikimore.simplefactory;


public class Test {

	public static void main(String[] args) throws Exception {
		CarFactory cf = new CarFactory();
		cf.buildcar("Benz");
		cf.buildcar("Volvo");
		cf.buildcar("BMW");
		cf.buildcar("QQ");
	}

}

以上为简单工厂 

可以造出工厂中已经定义的牌子的车子，CarFactory没有父类或子类，只能生产Car或者Car的子类

这是最简单的工厂模式，甚至不能称之为模式

同时我们可以将CarFactory的buildcar方法定义为静态方法，这样我们就不用去new一个CarFactory而直接生产Car的

这是我对简单工厂的一些浅显的理解，多流于表面，希望以后回看的时候可以有些体会！