@Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
   //设置跨域请求
   HttpServletResponse response = (HttpServletResponse) res;
   //此处ip地址为需要访问服务器的ip及端口号
   response.setHeader("Access-Control-Allow-Origin", "*");
   response.setHeader("Access-Control-Allow-Credentials", "true");
   response.setHeader("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, DELETE, TRACE, OPTIONS, PATCH");
   response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type,Token,Accept, Connection, User-Agent, Cookie");
   response.setHeader("Access-Control-Max-Age", "3628800");

   chain.doFilter(req, response);

}

这是过滤器还要做哪些百度了他说是这么搞的