设计模式_抽象工厂模式

系列产品（车、武器、食品补给……）




Vehicle.java

package com.bjsxt.dp.factory.abstractfactory;

public abstract class Vehicle {
public abstract void run();
}

Weapon.java

package com.bjsxt.dp.factory.abstractfactory;

public abstract class Weapon {
public abstract void shoot();
}

Food.java

package com.bjsxt.dp.factory.abstractfactory;

public abstract class Food {
public abstract void printName();
}

Car.java

package com.bjsxt.dp.factory.abstractfactory;

public class Car extends Vehicle {

public void run() {
System.out.println("冒着烟奔跑中car.......");
}
}

Broom.java

package com.bjsxt.dp.factory.abstractfactory;

public class Broom  extends Vehicle{

public void run() {
System.out.println("一路沙尘暴飞奔而来broom.....");
}

}

AK47.java

package com.bjsxt.dp.factory.abstractfactory;

public class AK47 extends Weapon{
public void shoot() {
System.out.println("哒哒哒...");
}
}

MagicStick.java

package com.bjsxt.dp.factory.abstractfactory;

public class MagicStick extends Weapon {

@Override
public void shoot() {
System.out.println("fire hu hu hu ...");
}

}

Apple.java

package com.bjsxt.dp.factory.abstractfactory;

public class Apple extends Food {
public void printName() {
System.out.println("apple");
}
}

MushRoom.java

package com.bjsxt.dp.factory.abstractfactory;

public class MushRoom extends Food {

@Override
public void printName() {
// TODO Auto-generated method stub
System.out.println("mushroom");
}

}

AbstractFactory.java

package com.bjsxt.dp.factory.abstractfactory;

public abstract class AbstractFactory {
public abstract Vehicle createVehicle();
public abstract Weapon createWeapon();
public abstract Food createFood();

}

DefaultFactory.java

package com.bjsxt.dp.factory.abstractfactory;

public class DefaultFactory extends AbstractFactory{

@Override
public Food createFood() {
// TODO Auto-generated method stub
return new Apple();
}

@Override
public Vehicle createVehicle() {
// TODO Auto-generated method stub
return new Car();
}

@Override
public Weapon createWeapon() {
// TODO Auto-generated method stub
return new AK47();
}

}

MagicFactory.java

package com.bjsxt.dp.factory.abstractfactory;

public class MagicFactory extends AbstractFactory {

@Override
public Food createFood() {
// TODO Auto-generated method stub
return new MushRoom();
}

@Override
public Vehicle createVehicle() {
// TODO Auto-generated method stub
return new Broom();
}

@Override
public Weapon createWeapon() {
// TODO Auto-generated method stub
return new MagicStick();
}

}

Test.java

package com.bjsxt.dp.factory.abstractfactory;

public class Test {
public static void main(String[] args) {
//DefaultFactory f = new DefaultFactory();
//AbstractFactory f = new DefaultFactory();
AbstractFactory f = new  MagicFactory();
Vehicle v = f.createVehicle();
v.run();
Weapon w = f.createWeapon();
w.shoot();
Food a = f.createFood();
a.printName();
}
}

简单工厂产生产品系列很麻烦，工厂泛滥

抽象工厂在产生新的产品品种的时候，改动的太多

理解Spring的Bean工厂

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans>

<bean id="v" class="com.bjsxt.spring.factory.Train">
</bean>

<!--  //v=com.bjsxt.spring.factory.Car  -->
</beans>

Moveable.java

package com.bjsxt.spring.factory;

public interface Moveable {
void run();
}

Car.java

package com.bjsxt.spring.factory;

public class Car implements Moveable{
public void run() {
System.out.println("冒着烟奔跑中car.......");
}
}

Train.java

package com.bjsxt.spring.factory;

public class Train implements Moveable{

@Override
public void run() {
System.out.println("小火车呜呜呜");
}

}

BeanFactory.java

package com.bjsxt.spring.factory;

public interface BeanFactory {
Object getBean(String id);
}

ClassPathXmlApplicationContext.java

package com.bjsxt.spring.factory;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.input.SAXBuilder;
import org.jdom.xpath.XPath;

public class ClassPathXmlApplicationContext implements BeanFactory  {
private Map<String, Object> container = new HashMap<String, Object>();

public ClassPathXmlApplicationContext(String fileName) throws Exception{
SAXBuilder sb = new SAXBuilder();
Document doc = sb.build(this.getClass().getClassLoader()
.getResourceAsStream(fileName));
Element root = doc.getRootElement();
List list = XPath.selectNodes(root, "/beans/bean");
System.out.println(list.size());

for (int i = 0; i < list.size(); i++) {
Element bean = (Element) list.get(i);
String id = bean.getAttributeValue("id");
String clazz = bean.getAttributeValue("class");
Object o = Class.forName(clazz).newInstance();
container.put(id, o);
System.out.println(id + " " + clazz);
}

}

@Override
public Object getBean(String id) {

return container.get(id);
}

}

Test.java

package com.bjsxt.spring.factory;

import java.io.IOException;
import java.util.Properties;

public class Test {

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws Exception {
BeanFactory f = new ClassPathXmlApplicationContext("com/bjsxt/spring/factory/applicationContext.xml");
Object o = f.getBean("v");
Moveable m = (Moveable)o;
m.run();
}

}