Context has been closed already solution

Error code

With such a piece of code, the context has been closed already error may occur during running, and once it occurs, it will make an error every time it runs in the future.

@Component
public class SpringContextUtil implements ApplicationContextAware {

    private static ApplicationContext context = null;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        ApplicationContextExt.context = applicationContext;
    }

	/**
	 * This static method allows you to retrieve the desired bean from the Spring context.
	 */
	public static <T> T getBean(Class<T> cls) {
        if (context == null)
            throw new IllegalStateException("no application context aviliable.");
        try {
            return (T) context.getBean(cls); // Wrong!
        } catch (BeansException e) {
			throw new RuntimeException(e);
        }
        return (T) null;
    }
}    

Cause analysis

However, when spring cloud context. Jar is included in the classpath, because the contextrefresher class will close the old context when the context is refreshed, so that the context in the static class has been closed, so this error will occur.

Trigger exploration

Find out the direct reason. Find out that a jar that you depend on listens to a notification from MQ. When you hear the message to be refreshed, you will refresh the context, which leads to this phenomenon.