用listener和beanfactoryaware实现bean的动态装载

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 console
		System.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。