传智播客Spring视频教程学习笔记4

三种实例化bean的方式

 

1.使用类构造器实例化

<bean id="personService" class="service.impl.PersonServiceBean"></bean>

2.使用静态工厂方法实例化

beans.xml

<bean id="personService2" class="service.impl.PersonServiceBeanFactory" factory-method="createPersonServiceBean"></bean>

PersonServiceBeanFactory.java

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

 

3.使用实例工厂方法实例化

beans.xml

<bean id="personServiceFactory" class="service.impl.PersonServiceBeanFactory"></bean> <bean id="personService3" factory-bean="personServiceFactory" factory-method="createPersonServiceBean2"></bean>

PersonServiceBeanFactory.java

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

 

三种方式测试成功

绝大部分都使用第一种实例化方法