bean实例化--工厂方法

1，编写bean

package com.songyan.factory2;

public class Bean3 {

}

2，编写工厂

package com.songyan.factory2;

public class MyBean3Factory {
public MyBean3Factory()
{
    System.out.println("bean3 实例化ing``````");
}

public Bean3 createBean()
{
    return new Bean3();
}
}

3， 编写xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
        <bean id="fac3" class="com.songyan.factory2.MyBean3Factory" ></bean>
        <bean id="bean3" class="com.songyan.factory2.Bean3" factory-bean="fac3" factory-method="createBean"></bean>      
        </beans>

4， 测试类

package com.songyan.factory;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestFactory {
public static void main(String[] args) {
    ApplicationContext  applicationContext=new ClassPathXmlApplicationContext("com/songyan/factory/beans2.xml");
    Bean2 bean=(Bean2)applicationContext.getBean("factory");
    System.out.println(bean);
}
}

5， 输出结果