自定义项目启动初始化信息的listener报错

时间:2023-03-10 06:28:53
自定义项目启动初始化信息的listener报错

自定义初始化组件代码如下:

@Component
public class InitComponent implements ServletContextListener, ApplicationContextAware { private static ApplicationContext applicationContext; @Override
public void contextInitialized(ServletContextEvent servletContextEvent) {
ServletContext sc = servletContextEvent.getServletContext();
//设置博主信息
BloggerService bloggerService = (BloggerService) applicationContext.getBean("bloggerService"); //错误处
Blogger blogger = bloggerService.getBlogger();
blogger.setPassword(null);
sc.setAttribute("blogger", blogger); } @Override
public void contextDestroyed(ServletContextEvent servletContextEvent) { } @Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
}

    写这段代码并且将其配在web.xml的listener中,用意在于项目启动的时候通过监听就初始化一些信息,

    但是每次启动错误处就会报NullPoint异常,经过排查才知道:

    Spring在项目启动时扫描注解配置的Bean是有顺序的,具体顺序是ApplicationContext.xml的顺序,

    问题就出在这,当扫描到这个类时如果BloggerService还没有被扫描到,就自然会报错了。