spring新手－－一个简单的问题（sprinf bean的销毁）

Question

小弟初学spring，可是在销毁bean的时候，代码如下：

applicationContext.xml





<beans <br=""> 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">





<bean id="user" class="com.xznu.springdemo.UserBean" <br=""> abstract="false" lazy-init="default" autowire="default"

dependency-check="default"  >

</bean></beans>



UserBean.java

package com.xznu.springdemo;



import org.springframework.beans.factory.DisposableBean;

import org.springframework.beans.factory.InitializingBean;



public class UserBean implements InitializingBean,DisposableBean{



private String name;

private int age;







public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public int getAge() {

return age;

}

public void setAge(int age) {

this.age = age;

}





public void afterPropertiesSet() throws Exception {

// 继承初始化接口

name = "wwx";

age = 23;

}




public void destroy() throws Exception {

// 继承销毁接口

name = null;

age = 0;

System.out.println("以销毁！"+this.name);

}




}



MainDemo.java

package com.xznu.springdemo;



import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import org.springframework.context.support.FileSystemXmlApplicationContext;



public class MainDemo {

public static void main(String args[]){

ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

UserBean userBean = (UserBean)context.getBean("user");

System.out.println("name:"+userBean.getName());

System.out.println("age:"+userBean.getAge());

}

}



只能初始化，却能销毁Bean，，不知道怎么回事？十分郁闷。。望高手给解决一下！谢谢！

Answer 1

你的问题应该是: 只能初始化，却不能销毁Bean 吧.

之所以没有依据你的预期调用DisposableBean.destroy()方法,是由于,整段代码结束了. 哈哈.

将代码改成下面这样:
[code="java"] public static void main(String args[]) {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("user.xml");
context.registerShutdownHook();

    UserBean userBean = (UserBean) context.getBean("user");
    System.out.println("name:" + userBean.getName());
    System.out.println("age:" + userBean.getAge());
}[/code]

注意这一句: context.registerShutdownHook();

其实, 它内部就是给 Runtime.getRuntime().addShutdownHook(this.shutdownHook);

也就是在jvm停掉之前执行 this.shutdownHook 里面定义的事情.
只有使用context.registerShutdownHook(); 注册了shutdownHook, 才可以触发剩下的事情, 比如说 DisposableBean.destroy()方法.