Java之接口与工厂详解一（附源码）

Posted 2022-12-14 mufeng_慕枫

前言

       接口是实现多重继承的途径，而生成遵循某个接口的对象的典型方式就是工厂方法设计模式。这与直接调用构造器不同，我们在工厂对象上调用的是创建方法，而该工厂对象将生成接口的某个实现的对象。理论上，通过这种方式，我们的代码将完全与接口的实现分离，这就使得我们可以透明地将某个实现替换成另一个实现。下面的实例展示了工厂方法的结构：

示例源码

package com.mufeng.theninthchapter;

interface Service 
	void method1();

	void method2();


interface ServiceFactory 
	Service getService();


class Implementation1 implements Service 

	public Implementation1() 
		// TODO Auto-generated constructor stub
	

	@Override
	public void method1() 
		// TODO Auto-generated method stub
		System.out.println("Implementation1 method1");
	

	@Override
	public void method2() 
		// TODO Auto-generated method stub
		System.out.println("Implementation1 method2");
	


class Implementation1Factory implements ServiceFactory 

	@Override
	public Service getService() 
		// TODO Auto-generated method stub
		return new Implementation1();
	



class Implementation2 implements Service 

	public Implementation2() 
		// TODO Auto-generated constructor stub
	

	@Override
	public void method1() 
		// TODO Auto-generated method stub
		System.out.println("Implementation2 method1");
	

	@Override
	public void method2() 
		// TODO Auto-generated method stub
		System.out.println("Implementation2 method2");
	


class Implementation2Factory implements ServiceFactory 

	@Override
	public Service getService() 
		// TODO Auto-generated method stub
		return new Implementation2();
	



public class Factories 

	public static void serviceConsumer(ServiceFactory fact) 
		Service s = fact.getService();
		s.method1();
		s.method2();
	

	public static void main(String[] args) 
		serviceConsumer(new Implementation1Factory());
		
		//Implementations are completely interchangeable
		serviceConsumer(new Implementation2Factory());
	

输出结果

Implementation1 method1
Implementation1 method2
Implementation2 method1
Implementation2 method2