用listener和beanfactoryaware实现bean的动态装载

来源：互联网发布：nba新秀排行榜2017数据编辑：程序博客网时间：2024/06/11 14:03

首先，写一个类，继承Beanfactoryaware

public class SpringBeanAware implements BeanFactoryAware {    public static BeanFactory beanFactory;    public void setBeanFactory(BeanFactory beanFactory) {        this.beanFactory = beanFactory;    }    public static Object getBean(String name) {        return beanFactory.getBean(name);    }    public static <T> T getBean(String name, Class<T> clazz) {        return (T)beanFactory.getBean(name);    }    public static boolean containsBean(String name) {        return beanFactory.containsBean(name);    }}

然后再spring的xml中声明：

<bean id="springBeanAware"class="com.iris.listener.SpringBeanAware" />

再次，在web.xml中声明监听器：

<listener><listener-class>com.iris.listener.IrisSedaDispatcher</listener-class></listener>

注意：此处如果使用的是spring mvc3，切不可图省事把所有spring配置都和mvc配置放一起，那样将导致监听不到（除非你想加载两次配置~）

监听器的代码如下：

public class IrisSedaDispatcher implements ServletContextListener {private ServletContext context = null;public void contextDestroyed(ServletContextEvent event) {// Output a simple message to the server's consoleSystem.out.println("The Simple Web App. Has Been Removed");this.context = null;}public void contextInitialized(ServletContextEvent event) {this.context = event.getServletContext();System.out.println("启动好了我勒个去");DefaultListableBeanFactory beanregistry = (DefaultListableBeanFactory) SpringBeanAware.beanFactory;System.out.println("关注factory：" + beanregistry); RootBeanDefinition define = new RootBeanDefinition(User.class); PropertyValue username = new PropertyValue("username", "hellokitty"); MutablePropertyValues values = new MutablePropertyValues(Arrays.asList(username)); define.setPropertyValues(values); define.setScope(BeanDefinition.SCOPE_SINGLETON); define.setAutowireCandidate(true); beanregistry.registerBeanDefinition("usertest", define); System.out.println((User) beanregistry.getBean("usertest")); System.out.println("初始化好了");    }}

然后，你就可以再程序中按如下方法获取到你新注册的bean了：

System.out.println(SpringBeanAware.getBean("statisticsMessageProducer"));

以上。备忘。

注意：以上方法只能用来注册普通的bean，你如果想注册个jms的listener、listenercontain、queue什么的，那么还是放弃吧，除非你想把spring的解析这些东西的源码再写一遍。我就是这么搞了一天最后才发现自己就是个蛋。算吸取教训了。

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