springboot里写了个过滤器没有作用

@WebFilter(filterName="urlFilter", urlPatterns="/*")
public class UrlFilter implements Filter{
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

        System.out.println("----------------------->过滤器被创建");
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws  ServletException, IOException {

        HttpServletRequest req = (HttpServletRequest) servletRequest;
        String requestURI = req.getRequestURI();
        System.out.println("--------------------->过滤器：请求地址"+requestURI);
        if(requestURI.contains("index")){
            servletRequest.getRequestDispatcher("/page").forward(servletRequest, servletResponse);
        }else{
            filterChain.doFilter(servletRequest, servletResponse);
        }
    }

    @Override
    public void destroy() {

        System.out.println("----------------------->过滤器被销毁");
    }

}

你有没有在spring boot启动类上添加@ServletComponentScan啊