嚴重: Exception sending context destroyed event to listener instance of class org.springframework.web.context.ContextLoaderListener
java.lang.IllegalStateException: BeanFactory not initialized or already closed - call 'refresh' before accessing beans via the ApplicationContext
at org.springframework.context.support.AbstractRefreshableApplicationContext.getBeanFactory(AbstractRefreshableApplicationContext.java:170)
at org.springframework.context.support.AbstractApplicationContext.destroyBeans(AbstractApplicationContext.java:921)
at org.springframework.context.support.AbstractApplicationContext.doClose(AbstractApplicationContext.java:895)
at org.springframework.context.support.AbstractApplicationContext.close(AbstractApplicationContext.java:841)
at org.springframework.web.context.ContextLoader.closeWebApplicationContext(ContextLoader.java:579)
at org.springframework.web.context.ContextLoaderListener.contextDestroyed(ContextLoaderListener.java:115)
at org.apache.catalina.core.StandardContext.listenerStop(StandardContext.java:5165)
at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:5838)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:221)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:149)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1700)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1690)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
情況1.
（鏈接：https://www.cnblogs.com/lomomiao/p/4269519.html）
正確寫法：
cxt = new ClassPathXmlApplicationContext("beans.xml");
productService = (ProductService)cxt.getBean(
"productTypeServiceBean"
);