使用注解定义过滤器这样是对的吗？如果不对应该怎么写

@WebFilter(filterName = "Encoding",urlPatterns = "/*",initParams = {@WebInitParam(name = "ENCODING",value = "utf-8")})
public class EncodingFilter implements Filter {
   private String encoding;

   @Override
   public void init(FilterConfig filterConfig) throws ServletException {
       if (filterConfig.getInitParameter("Encoding") != null) {
           encoding = filterConfig.getInitParameter("Encoding");
       }

   }

   @Override
   public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
       servletRequest.setCharacterEncoding(encoding);
       servletResponse.setCharacterEncoding(encoding);
       filterChain.doFilter(servletRequest, servletResponse);
   }

   @Override
   public void destroy() {
       encoding = null;
   }
}