设计模式之-工厂方法-FactoryMethod

定义一个用于创建对象的接口，让子类决定实例化哪一个类。FactoryMethod使一个类的实例化延迟到其子类。

 

适用性:

1.当一个类不知道它所必须创建的对象的类的时候。

2.当一个类希望由它的子类来指定它所创建的对象的时候。

3.当类将创建对象的职责委托给多个帮助子类中的某一个，并且你希望将哪一个帮助子类是代理者这一信息局部化的时候。
 

 

package pack.java.iworkfactory;

public interface IWork {
	/**
	 * 开始工作方法;
	 */
	public void doWork();
}

 

 

 

package pack.java.iworkfactory;

public interface IWorkFactory {
	/**
	 * 获取工作；
	 * @return
	 */
	public IWork getWork();
}

 

 

package pack.java.workfactoryimpl;

import pack.java.iworkfactory.IWork;
import pack.java.iworkfactory.IWorkFactory;

public class StudentFactory implements IWorkFactory{

	public IWork getWork() {
		// TODO Auto-generated method stub
		return new StudentWork();
	}

}

 

 

package pack.java.workfactoryimpl;

import pack.java.iworkfactory.IWork;

public class StudentWork implements IWork {

	public void doWork() {
		// TODO Auto-generated method stub
		System.out.println("学生做作业!");
	}
}

 

 

package pack.java.workfactoryimpl;

import pack.java.iworkfactory.IWork;
import pack.java.iworkfactory.IWorkFactory;


public class TeacherFactory implements IWorkFactory{

	public IWork getWork() {
		// TODO Auto-generated method stub
		return new TeacherWork();
	}

}

 

 

package pack.java.workfactoryimpl;

import pack.java.iworkfactory.IWork;

public class TeacherWork implements IWork {

	public void doWork() {
		// TODO Auto-generated method stub
		System.out.println("老师批改作业!");
	}

}

 

 

package pack.java.testfactorymethod;

import pack.java.iworkfactory.IWorkFactory;
import pack.java.workfactoryimpl.StudentFactory;
import pack.java.workfactoryimpl.TeacherFactory;

public class TestFactoryMethod {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//学生工厂方法;
		IWorkFactory studentFactory =  new StudentFactory();
		//学生开始工作;
		studentFactory.getWork().doWork();
		
		//老师工厂方法;
		IWorkFactory teacherFactory  = new TeacherFactory();
		//老师开始工作;
		teacherFactory.getWork().doWork();
	}
}

 

 

 

运行结果：

学生做作业!
老师批改作业!