三、Bean的懒加载和生命周期
最后更新于:2022-04-01 11:38:10
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");
}
~~~