工厂设计模式的两种实现方式

下面将介绍工厂模式的用户输入实现和配置文件实现

一、工厂设计模式通过用户输入实现

1、创建水果接口

Fruit接口

public interface Fruit {	public void buy();}2、创建实现水果接口的水果类
Apple类
public class Apple implements Fruit {	@Override	public void buy() {		System.out.PRintln("买苹果");	}}Pear类
public class Pear implements Fruit {	@Override	public void buy() {		System.out.println("买梨子");	}}Orange类
public class Orange implements Fruit {	@Override	public void buy() {		System.out.println("买橙子");	}}3、创建水果工厂接口
Factory接口
public interface Factory {	public Fruit createFruit(String str);}4、创建工厂实现类
FactoryImpl类
public class FactoryImpl implements Factory {	@Override	public Fruit createFruit(String str) {		if("apple".equals(str)){			return new Apple();		}else if("pear".equals(str)){			return new Pear();		}else if("orange".equals(str)){			return new Orange();		}		return null;	}}5、测试
public class Test {	public static void main(String[] args) {		Factory factory = new FactoryImpl();		Fruit fruit1 = factory.createFruit("apple");		Fruit fruit2 = factory.createFruit("pear");		Fruit fruit3 = factory.createFruit("orange");		fruit1.buy();		fruit2.buy();		fruit3.buy();	}}
输出结果：
买苹果买梨子买橙子
二、工厂设计模式通过配置文件实现
说明：本项目中的所有文件均在包factory_design_pattern1中
1、创建水果接口
Fruit接口
public interface Fruit {	public void buy();}2、创建实现水果接口的水果类
Apple类
public class Apple implements Fruit {	@Override	public void buy() {		System.out.println("买苹果");	}}Pear类
public class Pear implements Fruit {	@Override	public void buy() {		System.out.println("买梨子");	}}Orange类
public class Orange implements Fruit {	@Override	public void buy() {		System.out.println("买橙子");	}}
3、创建配置文件
配置文件名为
FactoryTest.properties
内容为：
ImplClass = factory_design_pattern1.Apple
注意：本实例中的所有文件均在包factory_design_pattern1中
4、创建水果工厂接口
Factory接口
public interface Factory {	public Fruit createFruit();}5、创建工厂实现类
FactoryImpl类
import java.io.IOException;import java.io.InputStream;import java.util.Properties;public class FactoryImpl implements Factory {	@Override	public Fruit createFruit() {		Properties p = new Properties();		InputStream in =null;		in = FactoryImpl.class.getResourceAsStream("FactoryTest.properties");		try {			p.load(in);		} catch (IOException e) {			// TODO Auto-generated catch block			e.printStackTrace();		}finally{			try {				in.close();			} catch (IOException e) {				// TODO Auto-generated catch block				e.printStackTrace();			}		}		Fruit fruit = null;		try {			fruit = (Fruit) Class.forName(p.getProperty("ImplClass")).newInstance();		} catch (InstantiationException | IllegalaccessException | ClassNotFoundException e) {			// TODO Auto-generated catch block			e.printStackTrace();		}		return fruit;			}}
6、测试
public class Test {	public static void main(String[] args) {		Factory factory = new FactoryImpl();		Fruit fruit = factory.createFruit();		fruit.buy();	}}
输出结果：
买苹果