凡是出现了大量的实例需要创建，而且具有共同的接口时，可以通过工厂方法模式进行创建。

一个接口: Sender

public interface Sender{

	public void send();

}

 

两个实现类: MainSender和SmsSender

public class MailSender implements Sender{

	@Override

	public void send(){

		System.out.println("Main Send...");

	}

}

public class SmsSender implements Sender{

	@Override

	public void send(){

		System.out.println("Sms Send...");

	}

}

 

一个接口: Provider

public interface Provider{

	public Sender produce();

}

 

两个实现类: MainFactory和SmsFactory

public class MailFactory implements Provider{

	@Override

	public Sender produce(){

		return new MailSender();

	}

}

 

public class SmsFactory implements Provider{

	@Override

	public Sender produce(){

		return new SmsSender();

	}

}

 

测试类

public class TestDemo{

	@Test

	public void testFactory(){

		Provider provider = new MailFactory();

		Sender sender = provider.produce();

		sender.send();

	}

}

结果:

     Main Send...