spring2.5学习笔记（一）：三种实例化bean的方式-优快云博客

本文链接：https://blog.youkuaiyun.com/sfwhhp/article/details/83708755

本文介绍Spring框架中三种实例化Bean的方法：使用默认构造器、通过静态工厂方法和通过实例工厂方法。并展示了如何配置这些Bean及其初始化方法。

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beans.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-2.5.xsd">
      <!--实例化bean方法一  -->
	 	<bean id="personservice" class="cn.itcast.service.impl.PersonServiceBean"  
			lazy-init="default" init-method="init">
		</bean>

		<!--实例化bean方法二  -->
		<bean id="personservice2" class="cn.itcast.service.impl.PersonServiceBeanFactory" factory-method="createPersonServiceBean">
		</bean>

		<!--实例化bean方法三  -->
		<bean id="personservicefactory" class="cn.itcast.service.impl.PersonServiceBeanFactory" >
		</bean>
		<bean id="personservice3" factory-bean="personservicefactory" factory-method="createPersonServiceBean2">
		</bean>
</beans>

包cn.itcast.service.impl中的两个类，
普通bean类：PersonServiceBean


package cn.itcast.service.impl;
import cn.itcast.service.IPersonService;
public class PersonServiceBean implements IPersonService {

	/* (non-Javadoc)
	 * @see cn.itcast.service.impl.IPersonService#save()
	 */
	//此方法在配置文件bean标签中用init-method属性调用
	public void init(){
		System.out.println("初始化");
	}
	public PersonServiceBean(){
		System.out.println("我被实例化了");
	}

	public void save(){
		System.out.println("这是PersonServiceBean类中的save方法");
	}

	public void destroy(){
		System.out.println("关闭打开的资源");
	}
}

PersonServiceBean所继承的接口：IPersonService


package cn.itcast.service;
public interface IPersonService {

	public abstract void save();

}

工厂类：PersonServiceBeanFactory


package cn.itcast.service.impl;

public class PersonServiceBeanFactory {

	public static PersonServiceBean createPersonServiceBean(){
		return new PersonServiceBean();
	}

	public  PersonServiceBean createPersonServiceBean2(){
		return new PersonServiceBean();
	}
}