java – 想要创建一个过滤器来检查cookie,然后从控制器保存对象

public class CookieFilter implements Filter {
????public void doFilter(ServletRequest req,ServletResponse res,FilterChain chain) throws IOException,ServletException {
????????HttpServletRequest request = (HttpServletRequest) req;
?       
        Cookie[] cookies = request.getCookies();
        if (cookies != null){
          for (Cookie ck : cookies) {
            if ("nameOfMyCookie".equals(ck.getName())) {
                // read the cookie etc,etc
                // ....
                // set an object in the current request
                request.setAttribute("myCoolObject",myObject)
            }
        }
????????chain.doFilter(request,res);
????}
????public void init(FilterConfig config) throws ServletException {
        // some initialization code called when the filter is loaded
????}
????public void destroy() {
        // executed when the filter is unloaded
????}
}

然后在web.xml中声明过滤器