tomcat中filter，servlet的@Autowired，@Resource注解报空指针

 在Filter中@Autowired或 @Resource 注解标注的变量不能注入,在Filter的init方法中加入如下代码即可: 

import org.springframework.web.context.support.SpringBeanAutowiringSupport;  
  
    public void init(FilterConfig config) throws ServletException {  
        SpringBeanAutowiringSupport.processInjectionBasedOnServletContext(this, config.getServletContext());  
    }