Spring入门Blog[三、Bean的懒加载和生命周期]

转自:http://blog.csdn.net/zhang6622056/article/details/7697863

懒加载
<?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"
           default-lazy-init="true">

<bean id="userDao" class="com.spring.dao.UserDaoImpl"></bean>

<bean id="userService" class="com.spring.service.UserServiceImpl" scope="prototype">
<property name="userDao" ref="userDao"></property>
</bean>

<!-- 这里的懒加载。也就是说在我们程序中真正get指定bean的
时候才会实例化这个bean而且也有全局的声明在xml文件上,否则在容器初始化的时候就开始声明初始化实例了。 -->
<bean id="userAction" class="com.spring.action.UserAction" autowire="byName" lazy-init="true">
</bean>
</beans>



生命周期：

bean的声明周期是要在配置文件中指定并且要在bean中编写的。下面看两个文件：
1、xml配置文件：

<bean id="userService" class="com.spring.service.UserServiceImpl" init-method="init" destroy-method="destory">
<property name="userDao" ref="userDao"></property>
</bean>

Java文件：

public class UserServiceImpl implements UserService{
private UserDao userDao;

public void init(){
System.out.println("init");
}

public void destory(){
System.out.println("destory");
}